design & engineering servicesdr 09

DR 09.05 Design & Engineering Services

INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 Phase1: Demand Response Potential

DR 09.05 Report

Prepared by:

Design & Engineering Services Customer Service Business Unit Southern California Edison

November 30, 2009

What’s Inside… Introduction

DR 09.05.01: Open and Closed Refrigerated Display Cases

DR 09.05.02: Anti-sweat Heaters on Glass Doors of Low-temperature Reach-in Display Cases

DR 09.05.03: Refrigerated Beverage Vending Machines

DR 09.05.04: Walk-in Coolers and Freezers

DR 09.05.05: Reach-in Refrigerators and Freezers

DR 09.05.06: Commercial Ice Machines

DR 09.05.07: Hot Food Holding Cabinets

DR 09.05.08: Residential Portable Spas

DR 09.05.09: Residential Appliances

DR 09.05.10: Residential Pool Pumps

DR 09.05.11: Home Office Equipment

DR 09.05.12: Home Entertainment Equipment

DR 09.05.13: Laptop Batteries and Docking Stations

Integration of Demand Response into Title 20 DR 09.05

Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under overall internal project number DR 09.05. This project was conducted with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer

This report was prepared by Southern California Edison (SCE) and funded by California utility customers under the auspices of the California Public Utilities Commission. Reproduction or distribution of the whole or any part of the contents of this document without the express written permission of SCE is prohibited. This work was performed with reasonable care and in accordance with professional standards. However, neither SCE nor any entity performing the work pursuant to SCE’s authority make any warranty or representation, expressed or implied, with regard to this report, the merchantability or fitness for a particular purpose of the results of the work, or any analyses, or conclusions contained in this report. The results reflected in the work are generally representative of operating conditions; however, the results in any other situation may vary depending upon particular operating conditions.

Southern California Edison November 2009 Design & Engineering Services

Integration of Demand Response into Title 20 DR 09.05

INTRODUCTION This project seeks to validate and establish demand response (DR) potential of thirteen residential and commercial appliance categories. This project addresses Phase 1 of potentially a multi-phase, multi-year effort to evaluate the possible incorporation of DR into the California Appliance Efficiency Regulations (Title 20).

This document presents the findings from Phase 1, which entails assessing the demand reduction for all thirteen appliance categories within Southern California Edison’s (SCE) service territory as well as statewide. The remainder of this document contains the full individual reports for each of the thirteen appliance categories investigated, as shown in the table below.

DR 09.05.01 Open and Closed Refrigerated Display Cases

DR 09.05.02 Anti-sweat Heaters on Glass Doors of Low-temperature Reach-in Display Cases

DR 09.05.03 Refrigerated Beverage Vending Machines

DR 09.05.04 Walk-in Coolers and Freezers

DR 09.05.05 Reach-in Refrigerators and Freezers

DR 09.05.06 Commercial Ice Machines

DR 09.05.07 Hot Food Holding Cabinets

DR 09.05.08 Residential Portable Spas

DR 09.05.09 Residential Appliances

DR 09.05.10 Residential Pool Pumps

DR 09.05.11 Home Office Equipment

DR 09.05.12 Home Entertainment Equipment

DR 09.05.13 Laptop Batteries and Docking Stations

Southern California Edison Page 1 Design & Engineering Services November 2009

Design & Engineering Services

INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR OPEN AND CLOSED REFRIGERATED DISPLAY CASES Phase1: Demand Response Potential

DR 09.05.01 Report

Prepared by:


November 30, 2009

What’s Inside… Executive Summary ..........................

Introduction.....................................

Market Size......................................

Market Barriers ................................

DR Strategies and Potential................

Results............................................

Recommendations ............................

Appendix .........................................

References ......................................

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Integration of DR into Title 20 for Open and Closed Refrig. Display Cases DR 09.05.01

Southern California Edison Design & Engineering Services November 2009

Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.01. DES project manager Scott Mitchell conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer


Integration of DR into Title 20 for Open and Closed Refrig. Display Cases DR 09.05.01

ABBREVIATIONS AND ACRONYMS

ASH Anti-sweat Heaters

CEUS Commercial End Use Survey

DOE US Department of Energy

DR Demand Response

EE Energy Efficiency

PG&E Pacific Gas & Electric

SCE Southern California Edison

SDG&E San Diego Gas & Electric

SMUD Sacramento Municipal Utility District

TDA Total Display Area

Southern California Edison Page i Design & Engineering Services November 2009

Integration of DR into Open and Closed Refrig. Display Cases DR 09.05.01

EXECUTIVE SUMMARY This project seeks to validate and estimate the Demand Response (DR) potential for refrigerated display cases in the California Appliance Efficiency Standards (Title 20).

A short-term study was conducted to estimate the total DR potential of refrigerated display cases in SCE service territory. This included an estimation of the population of display cases, contemplation of market acceptance factors, an exploration of potential DR strategies, and a determination of system-wide DR potential for each strategy.

Using projections from a recent Department of Energy energy efficiency rulemaking, the total demand of refrigerated display cases in a medium sized supermarket (45,000 ft2) was estimated to be 142 kW. Three DR strategies were investigated: case temperature reset, lighting reduction, and day-ahead temperature pull-down. The lighting measure is fairly straightforward and can achieve a 21,000 kW reduction with 10% market adoption. There are some concerns with effects on merchandising when lights are turned off, but these could probably be overcome with minimal efforts.

For the temperature reset and pull-down strategies, there are serious concerns about applicability to different types of equipment, food safety issues, and impact on customer economics. For example, medium temperature display cases will most likely not be included in such a strategy because of their inherent vulnerability to food spoilage. The most likely candidate for these strategies is low temperature display cases with transparent doors. Initial estimations suggest a 35,000 kW DR potential at 10% market acceptance for this class. However, the methodology employed here does not account for the duration of the DR period and may significantly overstate actual savings. More data on the temperature characteristics of display cases undergoing DR events is needed before a more accurate estimation of DR potential can be determined.

It is recommended that the DR strategy for display case lighting start immediately. There are major efforts currently underway to transform display case lighting from an energy efficiency perspective through new technologies such as LED. Incorporating DR into new installations that are planned to occur very shortly can provide more refined information on DR potential of this strategy.

The temperature reset and day ahead pull-down strategies need to be investigated more thoroughly before they can be incorporated into code. The impacts of DR on display case performance must be studied in a laboratory environment before implementation, rather than in the field, because of the potential problems associated with food safety. Once this performance data is known and there are more accurate estimates, industry participation in this effort will be crucial in order to ensure that a code effort is successful.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for open and closed refrigerated display cases. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from open and closed refrigerated display cases to home office equipment.

This project aligns well with the objectives of Southern California Edison’s (SCE) SmartConnect™ by fostering and accelerating the availability of DR-ready appliances in the market place. Furthermore, this project supports the California Public Utilities Commission goal of zero net energy (ZNE) for residential new construction by 2020 and commercial new construction by 2030.

Phase 1 of this potential three phase effort addresses the DR potential for open and closed refrigerated display cases; If Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for open and closed refrigerated display cases; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for open and closed refrigerated display cases.

This report reviews the findings from Phase 1 to estimate the DR potential for open and closed refrigerated display cases. This phase entails assessing the demand reduction associated with open and closed refrigerated display cases, the population statewide and within SCE service territory, and the market/customer acceptability of DR strategies associated with open and closed refrigerated display cases.

TECHNOLOGY DESCRIPTION Refrigerated display cases are used to merchandise perishable foods and other goods. “Display cases” is a generic term that encompasses numerous subcategories of equipment with varying physical and operational characteristics significantly impacting their energy consumption. The United States Department of Energy’s (DOE) 2009 energy efficiency rulemaking divided display cases into 38 different product classes in order to account for differences in energy consumption between these various configurations1. The following sections discuss several distinguishing characteristics that impact the feasibility of integrating DR into specific classes of display cases. (See Appendix for a breakdown of all equipment classes.)

OPERATING TEMPERATURE Display cases are designed to operate within specific temperature ranges based on the type of food they merchandize. Three temperature designations are commonly used to distinguish between the different types of cases: medium temperature (MT), low temperature (LT), and ice cream (IC). Design temperatures and applications are shown in Table 1.



TABLE 1. TEMPERATURE DESIGNATIONS

EQUIPMENT CLASS

DESIGNATION

RATING TEMPERATURE

APPLICATION

MT* 38°F Perishable fresh foods (meat, dairy, deli, and produce)

LT* 0°F Frozen foods (vegetables, juices, and frozen dinners)

IC* -15°F Ice cream

*DOE uses M, L, and I, respectively.

THERMAL BOUNDARY The overall construction of a display case’s thermal boundary has the greatest influence on its energy consumption. The two basic configurations are open and closed cases.

Open cases are most common in meat, dairy, and deli departments of supermarkets and are constructed such that at least one side of the case is permanently exposed to the surrounding environment. Because of this design open cases entrain warm moist air from the adjacent space. The moisture in the air condenses and freezes on the evaporator coil reducing its heat transfer effectiveness, choking airflow through the coil, and requiring more frequent defrosts to remove the ice build-up. The result is that these cases require up to 80% more cooling energy than similar closed cases.

Closed cases typically have a glass door or similar barrier that creates a full thermal boundary around the refrigerated space. These cases are most common in frozen food aisles of supermarkets and are slowly making their way into beverage and dairy departments. By removing the infiltration load, the cases can reduce the problems associated with frosting of the coil and are able to maintain more constant product temperature and use less energy.

Table 2 lists the different equipment class designations used by DOE to distinguish between basic case construction families.

TABLE 2. DISPLAY CASE FAMILY DESIGNATIONS

EQUIPMENT CLASS

DESIGNATION FAMILY

VOP Vertical Open

SVO Semi-vertical Open

HZO Horizontal Open

VCT Vertical Transparent Doors

VCS Vertical Solid Doors

HCT Horizontal Transparent Doors

HCS Horizontal Solid Doors

SOC Service Over Counter



REFRIGERATION SYSTEM CONFIGURATION Display case refrigeration systems come in two distinct forms, self-contained and remote. Self-contained display cases contain all refrigeration components, including compressors and condensers in one package; these systems reject heat to the surrounding space. Remote display cases contain only evaporators and evaporator fans, which are connected to a centralized refrigeration system.

A typical supermarket remote system contains several compressor racks, each with multiple compressors that are piped either in a loop or direct circuit to display cases, and walk-in coolers and freezers. The racks accommodate the evaporators by maintaining the lowest suction temperatures for the group. Typically, three to five compressor racks are employed to provide all refrigeration in the supermarket. Each compressor rack may have 3 to 5 compressors serving a series of loads with nearly identical evaporator temperature. In supermarkets the compressors are typically located in a mezzanine at the rear of the store and condensers are on the roof, rejecting heat to the outdoor environment.

Table 3 lists designations for refrigeration system configurations. (DR opportunities for remote refrigeration systems are covered in the DR 09.06.01 report.)

TABLE 3. OPERATING MODE DESIGNATIONS

EQUIPMENT CLASS

DESIGNATION OPERATING MODE

RC Remote Condensing

SC Self Contained



DISPLAY CASE COMPONENTS Display cases are an assemblage of many individual energy-consuming components working together to perform necessary functions. However, each component may have DR potential independent from the others. The major case components are shown in Figure 1 and their functions are described in the text immediately following the figure.

FIGURE 1. SCHEMATIC OF A REMOTE OPEN FRONT VERTICAL DISPLAY CASE

Evaporator Fans – circulate air through the cooling coil (evaporator) into the air distribution plenum and out to the refrigerated space. When fans are turned off, the refrigeration system alone is incapable of cooling the display case.

Lights – illuminate products for merchandising purposes. Typically, cases use T8 fluorescent lamps, but newer efficient technologies such as LED, fiber optic, and cold cathode lighting are now entering the market.

Anti-sweat heaters (closed cases only) – prevent condensation formation on exposed surfaces of closed cases. Typically, Anti-sweat heaters (ASH) are located in the door frames and around the perimeter of glass doors. Condensation on the frames can cause doors of LT cases to freeze shut, which puts door gaskets at risk of being torn. The condensation may also drip off the case and onto the floor, creating slip hazards for customers. Condensation on the inside surfaces of glass doors cause them to fog, obstructing the customer’s view of products inside the case. (DR opportunities for ASH are covered in the DR 09.05.02 report.)



Defrost heaters (LT only) – evaporator coils of display cases become frosted during normal operation due to entrainment of warm, moist air from the sales floor. Defrost cycles are typically initiated by a time clock (e.g., four times per day) and terminated either by a time clock (e.g., 45 minutes of defrost) or a temperature sensor (e.g., air leaving the evaporator has reached 42°F).

Compressors – perform mechanical work on a refrigerating fluid to take advantage of its thermodynamic properties and provide cooling to a space. In this report, compressors of both self-contained and remote equipment are considered. (Remote compressors are addressed further in the DR 09.06.01 report.)

Condenser fans – reject the heat absorbed by the refrigerant from the cold space to the ambient environment. Typically, the condenser is air-cooled and requires a fan to blow air across it. In larger remote systems, there may be an evaporatively-cooled cooling tower or other device used to reject heat, but all commonly require some sort of fan. (Remote condensers are addressed in more depth in the DR 09.06.01 report.)

CURRENT ENERGY CODE REQUIREMENTS The wide variety of components and configurations present in display cases has contributed to them remaining unregulated appliances in the United States. However, in January 2009, the DOE published energy standards for 38 display case equipment classes that apply to cases manufactured on or after January 1, 2012.2 These energy consumption standards are based on the total refrigerated volume for closed cases with solid doors and the total display area (TDA) for open cases and closed cases with transparent doors. No DR capabilities are included in this standard. Because this report only deals with sales floor units which must be open or have transparent doors for marketing purposes, the solid door cases will be ignored.

There currently are no California Title 20 standards, nor ENERGY STAR® programs addressing display cases.

DEMAND PROFILE AND ENERGY CONSUMPTION Because of the wide variation in product classes, demand and energy consumption cannot be easily reported as a single value. Figure 2 shows daily energy consumption as a function of Total Display Area (TDA) for 30 display case classes based on the DOE Standards.3 For a TDA of 60 ft2, daily energy consumption ranges from 9.73 kWh to 348.02 kWh depending on the type of equipment. This includes compressor and condensing unit consumption for both remote and self-contained equipment.

Assuming that energy is consumed in a consistent pattern over the day, the power demand could range from 272 W to over 9 kW per 40 ft2 of TDA. For the most prevalent case types (VOP.RC.M, VCT.RC.L, and VCT.RC.I) the range is approximately 1.0 kW to 1.5 kW for the same size TDA, see Figure 3.




0

50

100

150

200

250

300

350

400

0 10 20 30 40 50 60 7

TDA (sq ft)

Ener

gy C

onsu

mpt

ion

(kW

h/da

y)

0

VOP.RC.M SVO.RC.M HZO.RC.M VOP.RC.L HZO.RC.L

VCT.RC.M VCT.RC.L SOC.RC.M VOP.SC.M SVO.SC.M

HZO.SC.M HZO.SC.L VCT.SC.I HCT.SC.I SVO.RC.L

VOP.RC.I SVO.RC.I HZO.RC.I VCT.RC.I HCT.RC.M

HCT.RC.L HCT.RC.I SOC.RC.L SOC.RC.I VOP.SC.L

VOP.SC.I SVO.SC.L SVO.SC.I HZO.SC.I SOC.SC.I

FIGURE 2. DAILY ENERGY CONSUMPTION FOR SEVERAL DISPLAY CASE CLASSES AS A FUNCTION OF TDA

0

2

4

6

8

10

12

VOP.RC.M

SVO.RC.M

HZO.RC.M

VOP.RC.L

HZO.RC.L

VCT.RC.M

VCT.RC.L

SOC.RC.M

VOP.SC.M

SVO.SC.M

HZO.SC.M

HZO.SC.L

VCT.SC.I

HCT.SC.I

SVO.RC.L

VOP.RC.I

SVO.RC.I

HZO.RC.I

VCT.RC.I

HCT.RC.M

HCT.RC.L

HCT.RC.I

SOC.RC.L

SOC.RC.I

VOP.SC.L

VOP.SC.I

SVO.SC.L

SVO.SC.I

HZO.SC.I

SOC.SC.I

Case Type

Dem

and

(kW

/40

sf T

DA

)

FIGURE 3. DEMAND FOR SEVERAL DISPLAY CASE CLASSES ASSUMING 40 FT2 OF TDA


MARKET SIZE To estimate the number of supermarkets and grocery stores in SCE service territory and statewide, the information in the Commercial End-Use Survey (CEUS)4 report was used.5 Note that the information in CEUS was only for SCE, Pacific Gas and Electric (PG&E), San Diego Gas and Electric (SDG&E), and Sacramento Municipal Utility District (SMUD), and it did not include other municipal utilities in California.

While CEUS divided the total number of supermarkets and grocery stores into three main categories according to their annual energy consumption, see Table 4, it did not provide the actual number of stores for each category in the report. Nonetheless, CEUS provided the number of stores in each of the three size categories that was planned to be sampled, which can serve as a proxy for the actual distribution, see Table 4. For example, it was estimated that small size grocery stores comprise of about 27% of the total grocery stores. For medium and large size grocery stores, the distribution was estimated to be about 47% and 26% of the total grocery stores, respectively. There was no correlation between energy consumption and physical footprint size, so additional market research would be necessary to increase the accuracy of DR potential calculations.

TABLE 4. GROCERY STORES SIZE CLASSIFICATION AND DISTRIBUTION ACCORDING TO ANNUAL ENERGY CONSUMPTION

GROCERY STORE SIZE CATEGORIES

ANNUAL ENERGY CONSUMPTION (KWH/YEAR)

AVERAGE DISTRIBUTION (% OF TOTAL)

Small Size Less than 190,000 27%

Medium Size Between 190,000 and 1,600,000 47%

Large Size Greater than 1,600,000 26%

Table 5 summarizes the total number of stores in SCE, PG&E, SDG&E, and SMUD, as well as the number of stores according to their size classification for these service territories. Table 5 also shows the total number of stores for each of the three size classifications that can be used as a proxy for the actual number of stores in the state of California.

TABLE 5. TOTAL MARKET SIZE, AND MARKET SIZE FOR SMALL, MEDIUM, AND LARGE SIZE GROCERY STORES

SERVICE

TERRITORY TOTAL GROCERY

STORES SMALL SIZE

(27% OF TOTAL) MEDIUM SIZE

(47% OF TOTAL) LARGE SIZE

(26% OF TOTAL)

SCE 10,760 2,905 5,057 2,798

PG&E 12,293 3,319 5,778 3,196

SDG&E 2,632 711 1,237 684

SMUD 825 223 388 215

Total 26,510 7,158 12,460 6,893

A typical supermarket has approximately 60 to 80 display cases. About 60% of these are medium-temperature cases and 40% are low-temperature cases. Most of the medium-temperature cases are open display cases. DOE used the values from Table 6 for a medium size store to estimate energy consumption for a 45,000 ft2 supermarket. No guidance was



provided for smaller or larger stores, so multipliers of 50% and 125%, respectively, of the medium store length were used.

TABLE 6. LINE-UP LENGTH FOR 45,000 FT2 SUPERMARKET6

EQUIPMENT CLASS UNIT LENGTH (FT) LINE-UP LENGTH (FT) SMALL* MEDIUM LARGE*

VOP.RC.M 12 192 384 480

SVO.RC.M 12 42 84 105

VCT.RC.M 12.7 12.7 25.4 31.8

HZO.RC.M 12 12 24 30

SOC.RC.M 12 12 24 30

VOP.RC.L 12 12 24 30

VCT.RC.L 12.7 133.4 266.7 333.4

*Length for small and large supermarkets based on 50% and 125%, respectively, of medium supermarket length.

MARKET BARRIERS There are several over-arching factors that will impede acceptance of DR strategies by SCE customers. The concept of DR must be approached differently for these customers due to the critical role of electricity in their operation. While they may be adverse to DR in refrigeration, they must be reminded that without DR, the likelihood for extended, widespread power outages is increased. The losses resulting from such outages will likely far outweigh detrimental impacts of DR implementation. This follows the line of thought used in avoided cost analyses.

FOOD SAFETY

The FDA Food Code requires that all fresh foods be kept at a maximum temperature of 41°F to prevent spoilage and growth of food-borne illnesses. Because most of these fresh foods are maintained at temperatures at approximately 36°-38° F, there is little room for temperature fluctuation that results from shutting down any of the cooling equipment.

The most common DR measures for refrigeration involve turning off refrigeration equipment, which creates the risk of exceeding allowable temperature limits. Furthermore, many of the control systems used in the field today do not operate with tight tolerances, which increase the risk that temperatures will not be maintained properly. Thus, MT cases on the whole are not suitable for DR participation.

There may be an argument that cases holding non-perishable items, such as sodas, beer, sports drinks, and other beverages are capable of withstanding more pronounced temperature fluctuation. However, the inherent danger is that the type of product in a particular case may change over time. There is no way to guarantee that a case holding soda today will not be holding milk and dairy products 6 months from now. Thus, it appears that utilities have the potential of incurring significant liability if MT cases are included in any temperature-changing DR schemes.



LT and IC cases are typically able to withstand moderate changes in temperature because the products merchandised in them are maintained well below the freezing point and are not susceptible to thawing. Thus, DR strategies are more applicable here.

MARKETING IMPACTS

The main purpose of display cases is to merchandize perishable products to consumers. Any DR measures must not interfere with this purpose to the degree that they have a significant impact on the ability of cases to sell product. Historically in supermarkets, marketing aspects of cases have always been more important than energy consumption or thermal performance. For example, open display cases are commonplace in every supermarket today despite the opportunity to save nearly 80% on energy costs by switching to identical cases with doors. The reason is that the merchandisers are concerned that placing a door in between the customer and the product will so drastically cut into sales that any potential savings would be overshadowed by the loss of sales. In addition, any measures that reduce visibility of products to the customer by reducing lighting levels or allowing glass doors to fog more than usual will not be accepted by the market. Therefore, research projects are currently underway to assess the sales impact of adding doors to refrigerated display cases to address the concerns voiced by the grocery industry.

COMPLEXITY One of the biggest hurdles to overcome in widespread deployment in refrigeration programs for supermarkets is the lack of consistent refrigeration system design, even among stores operated by the same chain. These systems are connected to numerous types of display cases and walk-in coolers and incorporate any number of controllers using different communication protocols. The end result is that no two systems are alike and implementation of any DR strategy can require significant amounts of specialization for individual locations. This will likely increase implementation costs.

COST

The grocery industry operates on very tight profit margins; usually less than 1% of sales, and energy costs typically exceed profits. As such, they require energy efficiency and DR measures to have very short payback periods. Because some of the DR strategies proposed in this report may be very costly to implement in a particular store location, let alone across a chain with many vintages and store configurations, the associated DR rate structure must provide sufficient incentives to meet the payback criteria.



INTRUSION INTO SALES AREA

Like most business owners, grocery store operators are very hesitant to allow work crews in their facilities during operating hours. This is especially true when refrigerated cases are involved because customers who see any type of work undertaken on a case might assume that there is a problem with all refrigerated cases and refrain from purchasing any perishable products in the surrounding area. Furthermore, depending on the kind of instrumentation required to implement a particular DR strategy, technicians may be required to access the inner workings of the case. This is very labor-intensive and requires removal of a substantial amount of product from the case. The combination of labor intensiveness and possible after-hours schedule could significantly increase implementation labor costs, hampering the payback issues mentioned above.

DEMAND RESPONSE STRATEGIES AND POTENTIAL There are three strategies for achieving DR in display cases presented below. For the purpose of this evaluation, the DR potential of each strategy is defined in Equation 1.

EQUATION 1. DEMAND RESPONSE POTENTIAL

DRpotential = (kWreduction/unit) x (Market Size) x (Market Acceptance)

STRATEGY 1 – TEMPERATURE RESET

STRATEGY DESCRIPTION Temperature reset requires raising the thermostat setpoint temperature by a few degrees. Depending on how the refrigeration system is set up, this can either cause the compressor and condenser (condensing unit) to cycle off because the setpoint is now satisfied, or reduce the load on a multiplex remote compressor set-up, thereby reducing its power consumption. In any case, the suction pressure will be raised slightly, allowing the refrigeration system to operate at slightly higher efficiency and reduced demand.

TECHNICAL DEMAND REDUCTION If the condensing unit cycles off, there will be a 100% reduction in power until the various cooling loads warm the case to the new setpoint temperature. For remote systems tied into multiple compressor systems, there will be a reduction in refrigeration load but it will not necessarily lead to compressors shutting off completely. The duration of the off-cycle or reduced refrigeration load condition is completely dependent on the type of case involved and the overall cooling load effect of the surroundings, which will determine how quickly the case heats back up. Open cases will reach the new setpoint fairly quickly while closed cases will take more time due to their inherent isolation from the surroundings.

Where sustained DR is necessary, one option is to have multiple display case DR “groups” either within a site or across multiple sites. The groups can be rotated through short DR events to ensure they have coincident off-cycle times.



Because of all the variables involved, it is difficult to predict the actual demand reduction or duration, especially in an aggregate sense. The most realistic way to calculate the technical potential is to estimate total kW demand for the specified line-up lengths. Table 7 lists power demand for total length of each type of display case for three store sizes.

NOTE: For the purposes of the present exercise, the diversity effects mentioned above will intentionally be ignored because they are not included in Equation 1. As a result, the DR potential calculated here may not be realistically achievable for any significant duration of time.

TABLE 7. PER UNIT TOTAL DISPLAY CASE DEMAND FOR GIVEN STORE TYPES

EQUIPMENT

CLASS

TOTAL POWER DEMAND (KW)

POWER DEMAND

PER UNIT LENGTH

(KW/FT) SMALL MEDIUM LARGE

VOP.RC.M 0.192 36.9 73.7 92.2

SVO.RC.M 0.189 8.0 15.9 19.9

VCT.RC.M 0.056 0.7 1.4 1.8

HZO.RC.M 0.088 1.1 2.1 2.6

SOC.RC.M 0.107 1.3 2.6 3.2

VOP.RC.L 0.509 6.1 12.2 15.3

VCT.RC.L 0.13 17.4 34.8 43.4

TOTAL 71.5 142.7 178.4

MARKET ACCEPTANCE The biggest foreseen acceptance barrier to this DR strategy for MT equipment is compliance with FDA Food Code.. The risk of spoilage and potential for resulting illness overshadows benefits realized in the minds of many store operators. Application to LT equipment does not appear to be a major issue because there is a much wider acceptable temperature range and less opportunity for product quality to be reduced. However, for open LT cases, this strategy will likely result in significant temperature swings that could damage product. As a result, the only equipment class it would be applicable to is VCT.RC.L.

Additionally, there may be technical complications in the implementation of this strategy due to the wide array of equipment and controllers that have to interface with the DR dispatching device.

There also may be a sector of the market that is not willing to relinquish any control of their equipment to a utility or other outside actor, similar to the experience of programmable communicating thermostats for residential air conditioners.

It is estimated that the market acceptance is approximately 50% for the VCT.RC.L class.

DEMAND RESPONSE POTENTIAL Combining the display case DR potential from Table 7 and the market size information from Table 5, the DR achieved for various adoption rates on VCT. RC.L equipment is shown in Table 8.



TABLE 8. DR POTENTIAL FOR STRATEGY 1 FOR VARIOUS ADOPTION RATES

SIZE 1%

ACCEPTANCE

(KW)

5%

ACCEPTANCE (KW)

10%

ACCEPTANCE (KW)

20%

ACCEPTANCE

(KW)

50%

ACCEPTANCE (KW)

SCE 505 2,524 5,048 10,096 25,240 Small

CA 1,244 6,219 12,439 24,877 62,193

SCE 1,758 8,788 17,575 35,151 87,876 Med

CA 4,330 21,652 43,304 86,608 216,520

SCE 1,216 6,078 12,155 24,311 60,777 Large

CA 2,995 14,973 29,945 59,890 149,726

SCE 3,478 17,389 34,779 69,557 173,893 Total

CA 8,569 42,844 85,688 171,375 428,439

STRATEGY 2 – LIGHTING REDUCTION

STRATEGY DESCRIPTION Upon receiving a DR signal from the utility, lights in display cases will either shut off or switch to a dim state. Most cases in the field today are equipped with T8 fluorescent lamps that cannot be dimmed. A growing number of new cases are equipped with LED lighting, which can incorporate dimming strategies for energy efficiency gains. These dimming capabilities can be enabled during a DR event to provide prolonged low-power lighting.

TECHNICAL DEMAND REDUCTION The lighting load for display cases with T8 lighting is typically around 28 Watts per foot. LED lighting demand is approximately 40% less than T8, or 16 W/ft. Table 9 details the potential DR reduction for several market share scenarios, assuming that T8 is turned completely off and LEDs are switched to 20% of maximum power. (Note, as existing cases are retrofitted to incorporate LED lighting, the total DR potential decreases because of the inherently lower power draw.) This measure applies to all display case types.

TABLE 9. DISPLAY CASE LIGHTING DR POTENTIAL PER SITE

T8 / LED

MARKET SHARE

TOTAL POWER DEMAND (KW)

EQUIVALENT DR

POTENTIAL (KW/FT) SMALL MEDIUM LARGE

90% / 10% 0.0260 10.8 21.6 27.1

75% / 25% 0.0238 9.9 19.8 24.7

50% / 50% 0.0201 8.3 16.7 20.9

MARKET ACCEPTANCE The biggest foreseen acceptance barrier to this DR strategy is customer perception. Because this strategy directly affects the merchantability aspects of the display case, merchandisers may be hesitant to adopt it. There is a fear that customers who see a case with the lights out will think that it is not working properly and the products



inside are not good. This fear can be overcome using the LED dimming strategy or simply by placing signs in the aisle explaining why the lights are off. Signs of this nature have become more prevalent as companies are trying to promote their social consciousness through energy efficiency measures they have taken. It is estimated that the total market acceptance is 80%.

DEMAND RESPONSE POTENTIAL Using the 90% T8/10% LED figures, which are closest to the present state of the market, and market size information from Table 5 the DR achieved for various adoption rates is shown in Table 10.

TABLE 10. DR POTENTIAL FOR STRATEGY 2 FOR VARIOUS ADOPTION RATES

SIZE 1%

ACCEPTANCE

(KW)

5%

ACCEPTANCE (KW)

10%

ACCEPTANCE (KW)

20%

ACCEPTANCE

(KW)

50%

ACCEPTANCE (KW)

SCE 314 1,572 3,144 6,287 15,718 Small

CA 775 3,873 7,746 15,492 38,730

SCE 1,094 5,472 10,945 21,890 54,724 Med

CA 2,697 13,484 26,967 53,934 134,835

SCE 757 3,785 7,570 15,139 37,848 Large

CA 1,865 9,324 18,648 37,296 93,240

SCE 2,166 10,829 21,658 43,316 108,290 Total

CA 5,337 26,681 53,361 106,722 266,806

STRATEGY 3 – DAY-AHEAD DR TEMPERATURE PULL-DOWN

STRATEGY DESCRIPTION In the event that the utility has advance knowledge that a DR event will be required the next day, display case temperatures may be pulled down in advance. During the DR event, the refrigeration equipment can be shut off and the temperature allowed to float up for a period of time until it reaches a maximum allowable temperature.

As with the temperature reset strategy, this is most suitable for LT applications. Pulling down temperature on MT equipment can bring temperatures close to freezing (32°F), which can damage the products on display. The duration of off time is dependent on the type of case involved and surrounding environmental effects. Open display cases are not good candidates because of their increased exposure to neighboring conditions. Closed cases are better candidates due to more effective thermal isolation from the surroundings.

TECHNICAL DEMAND REDUCTION The potential DR for this measure is similar to that of Strategy 1, but should have longer duration due to the lower starting temperature. Because duration is not included in the DR potential calculation, there is no difference between this strategy and Strategy 1. Thus, the values in Table 7 apply here.



MARKET ACCEPTANCE Just as in Strategy 1, the biggest foreseen acceptance barrier to this strategy is compliance with FDA Food Code. However, market acceptance may be slightly higher due to the advanced warning inherent in this strategy rather than an instantaneous change in operation.

It is estimated that the market acceptance is 60% for the VCT.RC.M equipment class.

DEMAND RESPONSE POTENTIAL The total DR potential is the same as Strategy 1, so Table 8 applies.

RESULTS DR potential for display cases range from 2,166 kW with 1% acceptance when lighting reductions are undertaken within SCE service territory to 428,439 kW with 50% acceptance for temperature reset or day-ahead pull down statewide. Table 11 shows the range of total DR potential for the two strategies identified.

TABLE 11. RANGE OF DR POTENTIAL

1% ACCEPTANCE (KW)

50% ACCEPTANCE (KW)

STRATEGY

SCE CA SCE CA Temp Reset / Day-Ahead Pull Down 3,478 8,569 173,893 428,439 Lighting Reduction 2,166 5,337 108,290 266,806

RECOMMENDATIONS It is recommended that a codes and standards effort for Strategy 2, lighting reduction, move forward quickly. It would be easy to implement and would provide a significant amount of DR potential. Since lighting is not critical to the fitness of the products, it also will likely have a higher acceptance rate. Furthermore, many stores are on the verge of completing major retrofits to LED lighting systems once SCE rebates are in place early next year. This is a great opportunity to incorporate DR technology into the LED hardware, which might increase participation by allowing a dimming option rather than a fully off option.

Strategies 1 and 3 should also be pursued, but require further research to determine exactly how display cases will respond to DR events. The questions around duration of off-time and applicability to various display case types can only be answered through detailed technical testing. Significant industry involvement and buy-in are crucial to the implementation and success of these strategies.



APPENDIX

FIGURE 4. DOE DISPLAY CASE EQUIPMENT CLASSES




REFERENCES

1 DOE Commercial Refrigeration Equipment Final Rule Technical Support Document. pp. 3-18. http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/chp_3_cre_mta.pdf

2 DOE Commercial Refrigeration Equipment Final Rule Technical Support. http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/cre_final_rule.pdf

3 Id. At p.3. 4 California Energy Commission (CEC). California Commercial End-Use Survey (CEUS)

http://www.energy.ca.gov/ceus/index.html, accessed December 2009 5 Itron. 2006. “California Commercial End-Use Survey: Consultant Report,” CEC-400-2006-005. pp

27, 29, 42, 68-69. http://capabilities.itron.com/CeusWeb/Default.aspx, accessed November 2009. 6 Id.

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/chp_7_cre_energy_final.pdf p 7-10

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/chp_3_cre_mta.pdf

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/cre_final_rule.pdf

http://www.energy.ca.gov/ceus/index.html

http://capabilities.itron.com/CeusWeb/Default.aspx

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/chp_7_cre_energy_final.pdf%20p%207-10

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/chp_7_cre_energy_final.pdf%20p%207-10


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR ANTI-SWEAT HEATERS ON GLASS DOORS OF LOW-TEMPERATURE REACH-IN DISPLAY CASES Phase1: Demand Response Potential

DR 09.05.02 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size......................................

Market Barriers ................................


Results and Recommendations ...........

References ......................................

1

2

10

13

13

16

17

Integration of Demand Response into Title 20 for Anti-Sweat Heaters on Glass Doors of Low-Temperature Reach-In Display Cases DR 09.05.02


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.02. DES project manager Rafik Sarhadian conducted this technology evaluation with overall guidance and management from Scott Mitchell, Ramin Faramarzi, and Carlos Haiad of DES, and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer




ASH Anti-sweat heaters

DP Dew Point

DR Demand Response

EE Energy Efficiency

EER Energy Efficiency Ratio (Btu/hour/watts)

EFLH Equivalent Full Load Hours (hours/year)

Title 20 California’s Appliance Efficiency Regulations

LT Low-Temperature


SCT Saturated Condensing Temperature, (oF)

TTC Technology Test Centers



EXECUTIVE SUMMARY The specific focus of this project is to establish and quantify demand response (DR) potential for anti-sweat heaters on glass doors of low-temperature reach-in refrigerated display cases. The entire analysis and recommendations made in this project rely on findings from prior research conducted at Southern California Edison’s (SCEs) Technology Test Centers (TTC). This project seeks to evaluate the potential for DR utilizing anti-sweat heaters which could be to be incorporated into the California Appliance Efficiency Regulations, Title 20. Currently, there are no demand response regulations for anti-sweat heaters in Title 20, Federal regulations, or ENERGY STAR programs. Title 20 only regulates anti-sweat heaters on glass doors of walk-ins, and not on glass doors of reach-in refrigerated display cases.

Low-temperature reach-in refrigerated display cases are commonly found in grocery stores. These cases are equipped with anti-sweat heaters to prevent condensation on the glass doors. Absent any control mechanisms, the anti-sweat heaters on conventional glass doors require about 200 watts per door at all times. Most of the time, however, the temperature and humidity inside grocery stores do not necessitate continuously running heaters at full load. Therefore, the connected electrical power to these heaters can be lowered according to the indoor conditions of the grocery stores.

The results of this project indicate that the only practical and reasonable demand response strategy for anti-sweat heaters on conventional glass doors, without any control mechanism, is to reduce the power supplied to them from 100% to 60%. The basis for this conservative strategy is the typical indoor conditions (temperature and humidity) observed in grocery stores, and the empirical data that provides the target power level for these heaters according to indoor conditions in grocery stores. As a result, it is anticipated that the proposed DR strategy has the potential to reduce demand by 99 watts per door. Extending this finding to the potential market size in SCE service territory and California by assuming different market acceptance levels, the demand reductions are anticipated to range between 52 kW and 2,607 kW, and between 128 kW and 6,413 kW, respectively.

Although the proposed DR strategy yields power reductions, it is highly recommended to evaluate the cost effectiveness of this strategy relative to prominent energy efficiency solutions. Currently, rebate programs offer incentives for using controllers on anti-sweat heaters and using a new generation of glass doors that require low power. This is recommended because these two energy efficiency measures provide long-term benefits whereas reducing the power for certain periods of time provides short-term benefits. Additionally, the magnitude of the savings realized by using these two energy efficiency measures are far greater than the savings realized using the proposed DR strategy. From a DR cost effectiveness stance, it is also recommended to focus on grocery stores that are equipped with energy management systems and interfaces that offer two-way communication. Nonetheless, if the proposed DR strategy is to be pursued, field or laboratory assessments will provide improvement areas for the proposed strategy.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for anti-sweat heaters (ASH). It is part of a multi-phase effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to anti-sweat heaters.

This project aligns well with the objective of Southern California Edison’s (SCE) SmartConnectTM by fostering and accelerating the availability of DR-ready appliances in the market place. Furthermore, this project supports the California Public Utilities Commission goal of zero net energy for residential new construction by 2020 and commercial new construction by 2030.

Phase 1 of this potential three-phase effort addresses the DR potential for anti-sweat heaters; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for anti-sweat heaters; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for anti-sweat heaters.

Phase 1 is the focus of this project and establishes DR potential for anti-sweat heaters. This phase entails assessing the demand reduction associated with anti-sweat heaters, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with anti-sweat heaters.

TECHNOLOGY DESCRIPTION Low-temperature reach-in refrigerated display cases, Figure 1, can be found in small, medium, and large size grocery stores. They are used to merchandise frozen foods and ice cream. The air temperatures inside LT reach-in display cases can range from -5oF to -24oF. Due to cold case temperatures and the moisture content of the surrounding air, condensation becomes a problem in the operation of LT reach-in refrigerated display cases.

The temperature at which condensation occurs, which is known as dew point (DP), depends on the amount of moisture in the air in the surrounding environment. Condensation takes place when moist air contacts a cold surface with a temperature below the DP air temperature.

Condensation on a cold exterior surface of glass doors and doorframe is referred to as sweating. The exterior surfaces that are not well insulated or sealed are particularly vulnerable to the accumulation of condensation from the moisture in the surrounding air. Figure 1 illustrates sweating on the exterior glass surface (left picture) and exterior surface of the doorframe (right picture).



FIGURE 1. SWEATING ON THE EXTERIOR GLASS SURFACE (LEFT) AND THE DOORFRAME (RIGHT)

Further, as the moisture condenses and freezes on the interior surface of the glass doors it becomes opaque thus blocking visibility through the door with a surface of fog (see Figure 2). Fogging on the interior surface of the glass doors is mainly due to shoppers opening and closing the doors. As the glass doors are opened, the surrounding air circulates across the face of the glass doors and into the case while the cold air of the case spills out onto the floor. When the glass doors are closed, the surrounding air that is trapped inside the case begins to cool and the moisture it contains condenses and freezes on all surfaces.

FIGURE 2. FOGGING ON THE GLASS SURFACE

The problems with condensation are summarized below:

Sweating and fogging that blocks shoppers’ visibility through the display case, thus possibly affecting store sales

Condensation dripping on the floor that can be a slip hazard to shopper traffic



If the surface temperature of the case is very cold in a location where sweating occurs, a local build up of ice can occur. If ice forms on door seals additional problems can develop:

Build up of ice on door seals can render the seals rigid and no longer pliable, thus no longer effective at sealing the doors. This problem quickly compounds to more ice and more leakage across the door seal mating surfaces.

If condensate on or around the door seals freezes it can cause the door seals to become rigid and frozen to the mating surfaces of the case and door. The seals then become vulnerable to ripping and tearing when the doors are opened.

In order to minimize the problem of the cold surface temperatures that cause condensation to form on glass doors of LT reach-in display cases, ASH or sometimes referred to as anti-condensate heaters are used. ASH are electric resistance heaters that add heat in localized areas to keep the surface temperature above that which would allow condensation to occur. A portion of the electric connected load of ASH becomes the cooling load of the case. This load is ultimately removed by the compressor to maintain target product temperatures.

The conventional or standard glass doors used on LT reach-in display cases require three sets of heaters:

Case mullion heaters – located inside the case to keep the doors from freezing shut (green in Figure 3)

Doorframe heaters – located in the doorframe to keep the doors from freezing shut and provide some heat to the glass (red in Figure 3)

Glass heaters – located on the glass itself to raise its surface temperature and prevent condensation (blue in Figure 3)

FIGURE 3. TYPICAL ANTI-SWEAT HEATERS LOCATION FOR LOW-TEMPERATURE REACH-IN DISPLAY CASES



The structure of the components that make up the interface between the doors and the display case is illustrated in Figure 4. The interface is referred to as a mullion and serves to separate the opening of the display case into sections that can be covered with practical sized doors.

FIGURE 4. TOP VIEW OF MULLION AND DOORS

The mullion is the perimeter frame around the face of the display case where the doors close up against the display case. It divides the open face area of the case into separate openings that are each the size of a mating door. The vertical mullions between doors offer a convenient place for mounting internal lighting fixtures and their respective power supplies. Note, the lamp ballast mounted in the mullion channel. In addition to being conveniently close to the lamp, any heat given off by the ballast supplements that of the ASH in the mullion. Close to the door mating surface and behind an access panel are the heating elements of the mullion heaters (see Figure 5). The mullion heaters (white wire shown in Figure 5) help keep condensation off of the door gasket mating surface of the mullion. They also help keep the door gaskets dry and pliable while the doors are closed.

FIGURE 5. MULLION WITH DOORS AND MULLION ACCESS COVER REMOVED SHOWING WIRING FOR LIGHTS (BLUE) AND MULLION HEATER WIRE (WHITE)



The heat in each door consists of door frame heaters and a door glass heater. The heating elements for each of these components are separate but are typically fed through a single electrical connector at the bottom edge of the doorframe (see Figure 6 and Figure 7).

Doorframe heaters help keep condensate from forming on the perimeter of the doorframe. Heat from the doorframe also complements the mullion heaters in helping to keep the door gaskets dry and pliable while the doors are closed.

The glass of the doors is typically made up of several layers of glass separated by inert gas-filled chambers between each layer. This is done to improve the insulation across the doors by improving the thermal isolation from inside to outside the case. The inside surface of the exterior layer of glass is typically coated with a very thin layer of transparent, electrically conductive material that heats up when electric current is applied. This is referred to as glass heat and is the primary source of ASH for the surface of the glass.

FIGURE 6. DOORFRAME EDGE SHOWING DOOR HEATER RECEPTACLE AND CONNECTIONS

FIGURE 7. DOORFRAME MATING PLUG WHICH PROVIDES POWER TO DOOR HEATERS

Absent any control mechanisms for ASH, these heaters operate at full power 100% of the time. Typically the ASH controllers modulate the amount of heat supplied to the heaters as a function of indoor humidity or the amount of moisture detected on the surface of the glass. In addition, although the conventional or standard glass doors require three sets of heaters (mullion, glass and doorframe), the new generations of glass doors require either mullion heat only or mullion and glass heat.

Overall, there are at least four possible scenarios for ASH on LT reach-in glass doors. These four scenarios are outlined below. The only scenario that could potentially provide demand reductions is scenario 1. In scenario 2, the power supplied to ASH is controlled and optimized according to indoor environment humidity conditions. In scenario 3, special glass doors with low-powered ASH are used. In scenario 4, these low-powered ASH glass doors are controlled and further optimized according to indoor environment humidity conditions. As a result, in scenarios 2, 3 and 4 where the ASH heat requirements are already optimized, additional demand reductions would be insignificant and not be feasible. Therefore, the focus of this report is on ASH on conventional glass doors that are not equipped with any control mechanism (scenario 1). Possible scenarios:



1. ASH on standard or conventional glass doors without controller

2. ASH on standard or conventional glass doors with controller

3. ASH on new generation glass doors that require low heat without controller

4. ASH on new generation glass doors that require low heat with controller

CURRENT ENERGY CODE REQUIREMENTS Display cases have remained unregulated appliances in the United States (US) because of the difficulty in addressing the wide variety of components and configurations present in this product type. However, in January 2009, the US Department of Energy (DOE) published energy standards for 38 display case equipment classes, which becomes effective for case manufacturers on or after January 1, 2012.1 These energy consumption standards are based on the total refrigerated volume for closed cases and the total display area for open cases, due to the significant impact of open area on energy consumption. No DR capabilities are included in this standard.

ENERGY STAR programs do not address display cases. Title 20 standards, however, address only the ASH of the glass doors of walk-ins, and not the ASH of glass doors for reach-in display cases.2

DEMAND PROFILE AND ENERGY CONSUMPTION This section discusses both the direct and indirect or interactive effects of using ASH on LT reach-in display cases. Direct effect is simply the connected electric load of ASH. The interactive or indirect effect of ASH is the portion of the connected electric load of ASH that becomes the cooling load of the display case, which ultimately has to be removed by the compressors. Therefore, it is imperative to consider both direct and interactive effects of ASH.

DIRECT EFFECTS OF ASH According to the 2004-2005 Database for Energy Efficient Resources (DEER), the ASH connected electrical load for a conventional or standard glass door is 214 watts.3 The Gas Research Institute (GRI) reported total ASH connected electric load of 574 watts for a LT reach-in display case equipped with three conventional or standard glass doors.4 This is equivalent to ASH connected electric load of 191 watts (574 watts ÷ 3 doors) per door. Similarly, laboratory testing has shown a total of 544 watts of ASH connected electric load for a LT reach-in display case equipped with three conventional glass doors.5 This is equivalent to ASH connected electric load of 181 watts (544 ÷ 3 doors) per door.

Additional data was extracted from two leading U.S. display case manufacturers’ catalogs, namely Hill Phoenix6 and Hussmann.7 The results are summarized in Table 1. As shown in Table 1, the ASH connected electric load ranges between 188 and 216 watts per door, which is in close agreement with the three cited references above. Note that all the referenced display cases in Table 1 are equipped with conventional or standard glass doors.




TABLE 1. ASH POWER DEMAND FOR LOW-TEMPERATURE REACH-IN GLASS DOOR DISPLAY CASES FROM TWO LEADING U.S. MANUFACTURERS’ CATALOG

MODEL NUMBER

DISPLAY CASE DESCRIPTION TOTAL ASH POWER (WATTS)

ASH POWER PER DOOR (WATTS / DOOR)

ORZ6

Glass Door Reach-In Frozen Food/Ice Cream Merchandiser (3-door)

637 212

ORZH6

High Glass Door Reach-In Frozen Food/Ice Cream Merchandiser (3-door)

648 216

ONRZ6

Narrow Glass Door Reach-In Frozen Food/Ice Cream Merchandiser (3-door)

637 212

ONRZHH

6High Narrow Glass Door Reach-In Frozen Food/Ice Cream Merchandiser (3-door)

648 216

NRC7

Reach-In Ice Cream Merchandiser (3-door)

565 188

NRCV7

Reach-In Ice Cream Merchandiser, Vertical Lighting (3-door)

636 212

As indicated earlier, ASH stays on full load around the clock minus any control mechanism. Based on this assertion, the annual operation hours of ASH is 8,760 (365 days/year x 24 hours/day). Accordingly, the annual energy usage of ASH is estimated by simply multiplying power demand by annual hours of operation. Table 2 summarizes electric demand per door from all five cited sources and the corresponding annual electric energy usage per door. Table 2 also shows the arithmetic average value for demand and energy usage.

TABLE 2. SUMMARY OF ASH ELECTRIC DEMAND AND ANNUAL ELECTRIC ENERGY USAGE PER DOOR

DATA SOURCE

ELECTRIC DEMAND (WATTS/DOOR)

ANNUAL ELECTRIC ENERGY (KWH/DOOR/YR)

DEER 2004-20053 214 1,875

GRI4 191 1,673

Laboratory Testing5 181 1,586

Hill Phoenix (ORZ and ONRZ)6 212 1,857

Hill Phoenix (ORZH and ONRZH)6 216 1,892

Hussmann (NRC)7 188 1,647

Hussmann (NRCV)7 212 1,857

Arithmetic Average 202 1,770


INDIRECT OR INTERACTIVE EFFECTS OF ASH Laboratory testing revealed that about 35% of the sensible heat generated by the ASH ends up as a cooling load inside a LT reach-in display case.5 Using 202 watts (or 0.202 kW) per door as the connected electric power of ASH and assuming that ASH are on 100% of the time, the contribution of ASH to the total cooling load of the case is about 241 Btu/hr per door. Equation 1 shows the formula for calculating the cooling load contribution per door from ASH.

EQUATION 1. COOLING LOAD CONTRIBUTION FROM ASH

QASH = 35% x kWASH x ASH ON% x (3,413 Btu/hr/kW)

= 35% x (0.202 kW/door) x 100% x (3,413 Btu/hr/kW)

= 241 Btu/hr/door

This additional cooling load of 241 Btu/hr per door, however, needs to be removed by the LT compressors. To estimate the compressor power and energy required to remove this load, the compressor energy efficiency ratio (EER) and equivalent full load hours (EFLH) of operation are needed. Since both EER and EFLH are weather-dependent factors, they vary according to saturated condensing temperature (SCT) or climate zone. Table 3 summarizes EER and EFLH as a function of climate zone or the representative SCT.8 As shown in Table 3, the average EER for LT compressors is 5.26 Btu/hr/watts and EFLH is 5,696.

TABLE 3. REPRESENTATIVE AND AVERAGE LOW-TEMPERATURE COMPRESSORS’ ENERGY EFFICIENCY RATIO AND HOURS OF OPERATION AS A FUNCTION OF SATURATED CONDENSING TEMPERATURE

CLIMATE ZONE

REPRESENTATIVE

DRY BULB TEMP. (OF)

SATURATED

CONDENSING

TEMP. (OF)

ENERGY

EFFICIENCY RATIO

(BTU/HR/WATTS)

EQUIVALENT FULL

LOAD HOURS OF

OPERATION (HRS/YEAR)

1 69 79 7.74 5,477

2 96 106 4.98 5,517

3 89 99 5.57 5,609

4 88 98 5.67 5,744

5 83 93 6.14 5,625

6 92 102 5.31 5,819

7 83 93 6.14 5,880

8 89 99 5.57 5,855

9 94 104 5.14 5,796

10 100 110 4.67 5,734

11 104 114 4.37 5,528

12 100 110 4.67 5,615

13 101 111 4.59 5,744

14 108 118 4.08 5,681

15 111 121 3.88 6,269

16 89 99 5.57 5,240

Arithmetic Average 5.26 5,696



Subsequently, compressor power and annual energy usage due to additional cooling load imposed by ASH are calculated using Equation 2 and Equation 3, respectively. As outlined below, the LT compressors require 0.045 kW/door and 256 kWh/door/year to remove the additional cooling load of 241 Btu/hr per door.

EQUATION 2. COMPRESSOR POWER FOR REMOVING COOLING LOAD DUE TO ASH

kWcompressor = (Cooling Load Contribution from ASH) ÷ (EERcompressor x 1,000)

= (241 Btu/hr/door) ÷ (5.26 Btu/hr/watts x 1,000 watts/kW)

= 0.045 kW/door

EQUATION 3. ANNUAL COMPRESSOR ENERGY FOR REMOVING COOLING LOAD DUE TO ASH

kWhcompressor = kWcompressor x EFLH

= (0.045 kW/door) x (5,696 hours/year)

= 256 kWh/door/year

Overall, taking into account both direct and indirect effects, ASH require 0.247 kW or 247 watts per door. This power demand translates to 2,026 kWh per door, annually. Table 4 summarizes the results.

TABLE 4. OVERALL DEMAND AND ANNUAL ENERGY USAGE PER DOOR FOR ASH

ELECTRIC DEMAND (KW/DOOR)

ANNUAL ELECTRIC ENERGY (KWH/DOOR/YR)

Direct Effects 0.202 1,770

Indirect Effects 0.045 256

Total 0.247 2,026

MARKET SIZE To estimate the number of supermarkets and grocery stores in SCE service territory and statewide, the information in the Commercial End-Use Survey (CEUS)9 report was used.10 Note that the information in CEUS was only for SCE, PG&E, SDG&E, and SMUD, and it did not include other municipal utilities in California.

While CEUS divided the total number of supermarkets and grocery stores into three main categories according to their annual energy consumption (Table 5), it did not provide the actual number of stores for each category in the report. Nonetheless, CEUS provided the number of stores in each of the three size categories that was planned to be sampled, which serves as a proxy for the actual distribution (Table 5). For example, it was estimated that the small size grocery stores comprise about 27% of the total grocery stores. For medium and large size grocery stores, the distribution was estimated to be about 47% and 26% of the total grocery stores, respectively.

TABLE 5 GROCERY STORES SIZE CLASSIFICATION AND BREAKDOWN ACCORDING TO ANNUAL ENERGY CONSUMPTION

GROCERY STORE SIZE CATEGORIES

ANNUAL ENERGY CONSUMPTION (KWH/YEAR)

AVERAGE DISTRIBUTION (% OF TOTAL)

Small Size Less than 190,000 27%

Medium Size Between 190,000 and 1,600,000 47%

Large Size Greater than 1,600,000 26%



Table 6 summarizes the total number of stores in SCE, PG&E, SDG&E, and SMUD, as well as the number of stores according to their size classification for these service territories. Table 6 also shows the total number of stores for each of the three size classifications that can be used as a proxy for the actual number of stores statewide.

TABLE 6. TOTAL MARKET SIZE, AND MARKET SIZE FOR SMALL, MEDIUM, AND LARGE SIZE GROCERY STORES

SERVICE

TERRITORY TOTAL GROCERY

STORES SMALL SIZE

(27% OF TOTAL) MEDIUM SIZE

(47% OF TOTAL) LARGE SIZE

(26% OF TOTAL)

SCE 10,760 2,905 5,057 2,798

PG&E 12,293 3,319 5,778 3,196

SDG&E 2,632 711 1,237 684

SMUD 825 223 388 215

Total 26,510 7,158 12,460 6,893

Typically, small size grocery stores have one or two self-contained LT reach-in display cases.11 Therefore, the focus and attention is given to medium and large size grocery stores.

To estimate the number of LT reach-in glass doors in medium and large size grocery stores, the data gathered from reviewing the refrigeration schedule, past12 and current projects13, as well as the survey14 of several grocery stores was used. The data revealed that a typical medium size grocery store has on average about 35 LT reach-in glass doors. The number of LT reach-in glass doors in a typical large store ranges between 65 and 100, or on the average about 80 doors.

According to an Evaluation, Monitoring, and Verification (EM&V) report15, 41% of the grocery stores have a mechanism to cycle and control ASH of LT reach-in glass doors. In addition, about 32% of the grocery stores use a new generation of glass doors that requires low to no ASH. However, this report does not clarify the percentage of the grocery stores that have both a new generation of glass doors and a mechanism to control ASH power. Therefore, to take a conservative approach for estimating the number of standard or conventional LT reach-in glass doors without any ASH controllers in SCE service territory and statewide, these percentages are applied independently. Subsequently, Equation 4 is used to estimate the number of standard or conventional LT reach-in glass doors without ASH control in SCE service territory and statewide. Table 7 summarizes results for SCE service territory, and Table 8 summarizes the results for the entire State of California.

EQUATION 4. NUMBER OF CONVENTIONAL REACH-IN GLASS DOORS WITHOUT ASH CONTROL

No. of Glass Doors without ASH Control = No. of Stores x No. of Glass Doors per Store x % of Stores with ASH Control x % of Stores with New Generation of Glass doors



TABLE 7. NUMBER OF STANDARD OR CONVENTIONAL LOW-TEMPERATURE REACH-IN GLASS DOORS WITHOUT ASH CONTROL IN SCE SERVICE TERRITORY BY MARKET SIZE AND TOTAL

MEDIUM SIZE LARGE SIZE TOTAL

Number of LT Reach-In Glass Doors per Grocery Store 35 80 n/a

Number of Grocery Stores 5,057 2,798 7,855

Total Number of LT Reach-In Glass Doors 176,995 223,840 400,835

Percentage of Grocery Stores with ASH Control 41% 41% n/a

Percentage of Grocery Stores with New Generation of Glass Doors

32% 32% n/a

Total Number of Standard or Conventional LT Reach-in Glass Doors without ASH Control

23,222 29,368 52,590

TABLE 8. NUMBER OF STANDARD OR CONVENTIONAL LOW-TEMPERATURE REACH-IN GLASS DOORS WITHOUT ASH CONTROL IN CALIFORNIA BY MARKET SIZE AND TOTAL

MEDIUM SIZE LARGE SIZE TOTAL

Number of LT Reach-In Glass Doors per Grocery Store 35 80 n/a

Number of Grocery Stores 12,460 6,893 19,353

Total Number of LT Reach-In Glass Doors 436,100 551,440 987,540

Percentage of Grocery Stores with ASH Control 41% 41% n/a

Percentage of Grocery Stores with New Generation of Glass Doors

32% 32% n/a

Total Number of Standard or Conventional LT Reach-in Glass Doors without ASH Control

57,216 72,349 129,565



MARKET BARRIERS Reducing the ASH power of LT reach-in display cases can be associated with several risks that threaten potential sales, increased maintenance cost, and customer safety. These risks should be considered as primary market barriers.

It is important to refer back to the primary function of ASH to better understand the market barriers of DR strategies in this application. The primary function of ASH is to minimize the condensation problem that is common for LT reach-in display cases. Since grocery stores operate at low profit margins, fogging and sweating that blocks shoppers’ visibility through the glass doors can be associated with the risk of significant loss of revenue and profit. Condensation can also result in slippery walk ways and be a cause of injuries. In addition, ice build up on the surfaces of the case could cause the door assembly to freeze, which can be associated with the increased cost of maintenance, and perhaps loss of sales. Thus, the fundamental market barrier for any DR strategy for ASH is the uncertainty associated with the ability to minimize and eliminate the condensation problems.

DEMAND RESPONSE STRATEGIES AND POTENTIAL The following equation is used to determine the DR potential for this strategy.



Focusing on ASH for standard or conventional glass doors that are not equipped with any control mechanism, the only practical and reasonable DR strategy is to reduce the power supplied to the ASH to a level that does not cause condensation problems on the glass doors. In the following sections, this strategy and the rational for selecting this strategy is explained. Additionally, in the following sections the demand reduction benefits for using this strategy are quantified.

STRATEGY: REDUCE ASH POWER FROM 100% TO 60%

STRATEGY DESCRIPTION As its name implies, this strategy reduces the electrical power to the ASH. To determine the acceptable power reduction level for ASH, two issues need to be addressed: (1) indoor temperature and humidity levels inside grocery stores, and (2) minimum ASH power for that particular indoor temperature and humidity levels.

The field-monitored data from a previously conducted project by SCE’s TTC was used to establish average and typical indoor dry bulb (DB) and relative humidity (RH) inside the grocery stores. Figure 8 depicts the hourly monitored DB temperature and RH inside a supermarket located in Thousand Oaks, California, which is classified as climate zone 9. The average monthly DB temperature and RH are also shown in Figure 8. Based on the presented field data, it seems to be reasonable and appropriate to consider an average indoor DB temperature of 72oF and an average indoor RH of 45% for this grocery store. It is worthwhile to point out that the indoor DB temperature did not vary significantly and remained relatively constant. While the variations in indoor RH were to some extent significant and exceeded 45% level in some instances, the monthly average indoor RH did not exceed 45%. This is an important observation because it underscores the fact that there might be instances




where reducing the ASH power may perhaps cause condensation on glass doors, hence may not be a desirable option.

0

10

20

30

40

50

60

70

80

90

100

Monitoring Periods (March 1997 to October 1997)[hourly data -- SCE's large supermarket in Thousand Oaks, CA]

Sto

re D

ry B

ulb

Te

mp

era

ture

(oF)

an

d R

ela

tive

Hu

mid

ity (

%)

Mar MayApr Jun Jul Aug Sep Oct

Avg. = 70oF Avg. = 70oF Avg. = 71oF Avg. = 67oFAvg. = 71oF Avg. = 72oF Avg. = 70oFAvg. = 72oF

Avg. = 31% Avg. = 33% Avg. = 41% Avg. = 32%Avg. = 45% Avg. = 43% Avg. = 35%Avg. =45%

45% RH Level

FIGURE 8. INDOOR DRY BULB TEMPERATURE AND RELATIVE HUMIDITY AT A SUPERMARKET IN THOUSAND OAKS, CA

SCE’s TTC laboratory test data revealed that when the indoor DB temperature was 75oF and RH was 45% (equivalent to a DP temperature of 52.2oF), providing 83 watts of ASH power per door was sufficient to prevent condensation.5 In other words, when the indoor DB was 75oF and RH was 45%, there was no need to run the ASH at full power of 181 watts per door. In fact, the temperature of the exterior of the glass door was 66oF and the doorframe temperature was 64oF, which both were above the indoor DP temperature of 52.2oF. The interior glass temperature at 24oF was below the indoor DP temperature of 52.2oF. As a result, a fogging effect was observed on the interior surface of the glass. It took about 48 seconds to clear the fog on the interior glass surface when only 83 watts per door was supplied to ASH. Under the scenario where 181 watts per door was supplied to ASH, it took about 38 seconds to clear the fog on the interior glass surface. The fogging effect on the interior surface of the glass, however, is inevitable even at low humidity levels of 35%.

Overall, this laboratory test finding suggested that when the indoor DB temperature was 75oF and RH was 45%, which is similar to average DB temperature and RH inside a typical grocery store, the power supplied to ASH can be reduced by 54% while preventing condensation on the glass doors. That is, ASH only required 46% of full power to prevent condensation under ambient conditions of 75oF DB and 45% RH. This indicates a reduction from 181 watts per door to 83 watts per door.

Based on the foregoing discussions, the ASH power can be reduced from 100% to 46% since the typical DB temperature and RH inside the grocery stores are 72oF and 45%, respectively. To take a conservative approach, based on our engineering experience, instead of using 46%, 60% will be used as an acceptable power level for ASH in this strategy. Accordingly, the strategy is to reduce the ASH power from 100% to 60% to ensure that there are no condensation problems on the glass doors.


TECHNICAL DEMAND REDUCTION Reducing the ASH power from 100% to 60% not only reduces the connected electrical power of ASH but it also reduces the cooling load requirements, and thereby compressor power. Reducing the ASH power from 100% to 60% means that the ASH requires 121 (202 x 60%) watts per door instead of 202 watts per door. In other words, the direct effect of reducing ASH power from 100% to 60% is a demand reduction of 81 (202 – 121) watts per door or 0.081 kW per door.

Reducing the ASH power demand by 81 watts per door reduces the cooling load of the case by 97 Btu/hr/door (refer to Equation 1 for calculation methodology). This reduction in total cooling load in turn reduces the compressor power requirement by 0.018 kW per door (refer to Equation 2 for calculation methodology). Overall, coupling both direct and indirect impacts, 0.099 kW per door is the anticipated demand reduction for this DR strategy.

MARKET ACCEPTANCE The uncertainty associated with potential adverse impacts of reduced ASH on the sales and revenue can affect market acceptance. Therefore, the primary barrier for this strategy is the skepticism about ASH’s ability to prevent condensation at 60% power level. Since there is a great deal of unknowns associated with estimating a market acceptance level, market acceptance levels of 1%, 5%, 10%, 20%,and 50% are used for the purpose of this evaluation.

DEMAND RESPONSE POTENTIAL Table 9 summarizes the results for various market acceptance levels in SCE service territory and statewide, respectively.

TABLE 9. DEMAND RESPONSE POTENTIAL FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND STATEWIDE

DR POTENTIAL (KW)

DEMAND

REDUCTION (KW/DOOR)

MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE SCE 52,590 52 261 521 1,043 2,607

0.099 CA 129,565 128 641 1,283 2,565 6,413



RESULTS The results indicate that the only practical and reasonable DR strategy for ASH on conventional glass doors without any control mechanism is to reduce the power supplied to them from 100% to 60%. The basis for this conservative strategy is the typical indoor conditions (DB and RH) observed in grocery stores and the empirical data that supported the need for reducing ASH power under those typical indoor conditions. As a result, it is anticipated that this DR strategy has the potential to reduce the demand by 0.099 kW per door. Extending this finding to the potential market size in SCE service territory and statewide by assuming different market acceptance levels, the demand reductions are anticipated to range between 52 kW and 2,607 kW, and between 128 kW and 6,413 kW, respectively.

RECOMMENDATIONS It is recommended to evaluate the cost effectiveness of this DR strategy relative to the current measures in energy efficiency rebate programs. Such evaluation will enhance the understanding about the value of this DR strategy. Currently, rebate programs offer incentives for using ASH controller and new generation of glass doors that require low ASH power. It is important to note that these two energy efficiency measures (ASH controller and new generation glass doors) provide long-term benefits, whereas this DR strategy reduces partially the power for short periods of time. In addition, the magnitude of demand reduction and energy savings realized by using these two energy efficiency measures are far greater than the savings realized using the proposed DR strategy.

Considering DR cost effectiveness, it is also recommended to focus on grocery stores that are equipped with energy management systems and a two-way communication interface. If the proposed DR strategy is to be pursued, however, field or laboratory assessments will provide improvement areas for the proposed DR strategy.




REFERENCES

1 Energy Independence and Security Act of 2007. Retrieved from

http://www.govtrack.us/congress/billtext.xpd?bill=h110-6 2 California Energy Commission. 2007. “2007 Appliance Efficiency Regulations,”

CEC-400-2007-016-Rev 1, p. 109. 3 2004-2005 Database for Energy Efficiency Resources (DEER) Update Study. 2005. Itron, Inc.

pp. 7-91. http://www.calmac.org/publications/2004-05_DEER_Update_Final_Report-Wo.pdf 4 Gas Research Institute. 2000. “Investigation of Relative Humidity Impacts on the Performance and

Energy Use of Refrigerated Display Cases,” p. 129. http://www.gastechnology.org/webroot/app/xn/xd.aspx?it=enweb&xd=10AbstractPage/12327.xml

5 Faramarzi, R., Coburn, B. and Sarhadian, R. 2001. “Anti-Sweat Heaters in Refrigerated Display Cases.” ASHRAE Journal, vol. 43, no. 6, pp 64-65. https://eweb.ashrae.org/eweb/DynamicPage.aspx?Site=ASHRAE&WebKey=69c74d61-facd-4ca4-ad83-8063ea2de20a&listwhere=(prd_etab_ext%20LIKE%20'%25124%25'%20AND%20prd_etab_ext%20LIKE%20'%251197%25')

6 Hill Phoenix Merchandiser Engineering Reference Manual. 2001. pp 170-177. 7 Hussmann Merchandiser Data. 1993. Ice Cream Merchandiser Section. 8 SCE Design and Engineering Services, Work Paper (WPSCNRRN0008.0). 2007. “New Refrigeration

Display Cases with Doors – Low-Temperature and Medium-Temperature.” 9 California Energy Commission (CEC) California Commercial End-Use Survey (CEUS). Retrieved from

http://www.energy.ca.gov/ceus/index.html, accessed December 2009 10 Itron. 2006. “California Commercial End-Use Survey: Consultant Report,” CEC-400-2006-005.

pp 27, 29, 42, 68-69. http://capabilities.itron.com/ceusweb/default.aspx, accessed November 2009.

11 Southern California Edison. 2002. “Small Grocery Store Integrated Energy Efficiency Improvements: Final Report.” ET 02.05. p. 4. http://www.etcc-ca.com/component/content/article/22/2613-integrated-efficiency-improvements-for-small-grocery-stores

12 Southern California Edison. 2006. “Fiber Optic Lighting in Low-Temperature Reach-in Refrigerated Display Cases: Final Report.” ET 05.04. p. 6. http://www.etcc-ca.com/component/content/ article/31/2370-fiber-optic-display-case-lighting-system

13 Southern California Edison. Final Report In Progress. “LED in Low-Temperature Reach-in Refrigerated Display Cases”. ET 06.06. http://www.etcc-ca.com/component/content/ article/31/2781-led-in-low-temperature-reach-in-refrigerated-display-cases

14 Southern California Edison. 2001. Unpublished Survey. Refrigeration and Thermal Test Center’s Survey of Grocery Stores.

15 Final Evaluation, Monitoring, and Verification (EM&V) Report for 2004-2005 EnergySmart Grocer Program. 2006. PWP, Inc. p. 39, Exhibit 18. http://www.calmac.org/events/7_SmartGrocer_Prog_PECI.ppt

http://www.govtrack.us/congress/billtext.xpd?bill=h110-6

http://www.calmac.org/publications/2004-05_DEER_Update_Final_Report-Wo.pdf

http://www.gastechnology.org/webroot/app/xn/xd.aspx?it=enweb&xd=10AbstractPage/12327.xml

https://eweb.ashrae.org/eweb/DynamicPage.aspx?Site=ASHRAE&WebKey=69c74d61-facd-4ca4-ad83-8063ea2de20a&listwhere=(prd_etab_ext%20LIKE%20'%25124%25'%20AND%20prd_etab_ext%20LIKE%20'%251197%25





http://capabilities.itron.com/ceusweb/default.aspx

http://www.etcc-ca.com/component/content/article/22/2613-integrated-efficiency-improvements-for-small-grocery-stores

http://www.etcc-ca.com/component/content/article/22/2613-integrated-efficiency-improvements-for-small-grocery-stores

http://www.etcc-ca.com/component/content/article/31/2370-fiber-optic-display-case-lighting-system

http://www.etcc-ca.com/component/content/article/31/2370-fiber-optic-display-case-lighting-system

http://www.etcc-ca.com/component/content/%0Barticle/31/2781-led-in-low-temperature-reach-in-refrigerated-display-cases

http://www.etcc-ca.com/component/content/%0Barticle/31/2781-led-in-low-temperature-reach-in-refrigerated-display-cases

http://www.calmac.org/events/7_SmartGrocer_Prog_PECI.ppt


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR REFRIGERATED BEVERAGE VENDING MACHINES Phase1: Demand Response Potential

DR 09.05.03 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size......................................

Market Barriers ................................


Results............................................


References ......................................

1

3

10

11

11

18

19

20

Integration of DR into Title 20 for Refrigerated Beverage Vending Machines DR 09.05.03


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.03. DES project manager Rafik Sarhadian conducted this technology evaluation with overall guidance and management from Scott Mitchell, Ramin Faramarzi, Carlos Haiad of DES, and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer




CFVM Closed-Front Vending Machine

DB Dry Bulb

DR Demand Response

GFVM Glass-Front Vending Machine

NTBV Next-to-be-vended

RH Relative Humidity



TTC Technology Test Centers

VM Vending Machine



EXECUTIVE SUMMARY The objective of this report is to establish and quantify demand response (DR) potential for refrigerated beverage vending machines. The entire analysis and recommendations made in this project rely on findings from prior research conducted at Southern California Edison’s (SCEs) Technology Test Centers (TTCs). This project seeks to evaluate the potential for DR using refrigerated beverage vending machines that can be incorporated into the California Appliance Efficiency Regulations, Title 20. Currently, there are no demand response regulations for refrigerated beverage vending machines in Title 20, Federal regulations, or ENERGY STAR programs. These standards only regulate the maximum daily energy consumption of refrigerated beverage vending machines.

The refrigerated beverage vending machines are commonplace both indoors and outdoors at gas stations, convenience stores, retailers, schools, hospitals, hotels and motels, parks, and office buildings. They fit into one of two categories: closed-front and glass-front. The majority of refrigerated beverage vending machines are located outdoors. Closed-front refrigerated beverage vending machines make up 92% of the market, and glass-front the remaining 8%. This study focuses on closed-front vending machines because of their large presence. The older generation of closed-front machines uses about 600 watts, which is the basis for demand reduction analysis in this project.

The results of this project indicate that there are at least six different DR strategies. Some of the proposed strategies, however, are suitable for the units that are located indoors, or are exposed to milder (less than 90oF dry bulb temperature) ambient conditions. Table 1 summarizes all six strategies and their corresponding range-of-demand mitigation in SCE’s service territory and statewide using minimum and maximum market acceptance levels of 1% and 50%, respectively.

TABLE 1. SUMMARY OF PROPOSED STRATEGIES AND DEMAND REDUCTIONS IN SCE’S SERVICE TERRITORY AND STATEWIDE

STRATEGIES

AND DESCRIPTIONS

DEMAND REDUCTION IN SCE SERVICE TERRITORY

(KW) [1% TO 50% MARKET ACCEPTANCE]

DEMAND REDUCTION IN THE STATE OF CALIFORNIA

(KW) [1% TO 50% MARKET ACCEPTANCE]

Strategy 1: Turn off the entire unit

1,541 to 77,056 4,423 to 221,150

Strategy 2: Turn off the lighting system

292 to 14,592 838 to 41,879

Strategy 3: Turn off one of the evaporator fan motors

59 to 2,944 169 to 8,450

Strategy 4: Turn off the lighting system and one of the evaporator fan motors

351 to 17,536 1,007 to 50,329

Strategy 5: Reset the temperature setpoint

1,172 to 58,624 3,365 to 168,251

Strategy 6: Reset the temperature setpoint and turn off the lighting system

1,464 to 73,216 4,203 to 210,130



Although the proposed DR strategies yield power reductions, it is highly recommended to evaluate the cost effectiveness of the strategies relative to prominent energy efficiency solutions. Currently, rebate programs offer incentives for using a new generation of high- efficiency refrigerated beverage vending machines. This is recommended because using new generation high-efficiency units provides long-term benefits, whereas reducing the power for certain periods of time provides short-term benefits. In addition, the magnitude of the savings realized by using high-efficiency units is far greater than the savings realized using the proposed DR strategies. It is also necessary to consider the adverse impact of some of the proposed demand response strategies on product quality. Specifically, syrup quality of the beverages at higher temperatures can alter taste and subsequently consumers’ acceptance.

Additional recommendations include evaluating the cost effectiveness of targeting either the older and inefficient generation of vending machines or the newer one, such as ENERGY STAR-qualified units. It is anticipated that strategies on the older generation of vending machines will yield greater demand reductions at higher implementation costs. In contrast, the demand reductions and cost of implementation for newer generation vending machines is anticipated to be lower. Nonetheless, if the proposed DR strategies are pursued, field or laboratory assessments will provide improvement areas for the proposed strategies.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for refrigerated beverage vending machines (VMs). It is part of a multi-phase effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from home office equipment to vending machines.

This project aligns well with the objectives of Southern California Edison’s (SCE) SmartConnectTM by fostering and accelerating the availability of DR-ready appliances in the market place. Furthermore, this project supports the California Public Utilities Commission’s goal of zero net energy for residential new construction by 2020 and commercial new construction by 2030.

Phase 1 of this potential three-phase effort addresses the DR potential for VMs; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for VMs; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for VMs.

This report reviews the findings from Phase 1 and estimates the DR potential for VMs. This phase entails assessing the demand reduction associated with VMs, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with VMs.

TECHNOLOGY DESCRIPTION Refrigerated VMs are designed to store bottled or canned beverages at a prescribed temperature and dispense product in exchange for currency. Many refrigerated VMs operate in outdoor locations where they are subjected to extreme ambient conditions, especially in California.

Vending machines can be divided into two main categories, closed-front (Figure 1Figure 1

, left picture) and glass-front ( , right picture). Closed-front vending machines (CFVMs) house products inside a completely opaque insulated compartment. Some models may have a display window where sample products are viewed, but the products to be vended are contained behind an insulated door and cannot be seen. These machines typically have a full-size illuminated advertisement panel on the front. Glass-front vending machines (GFVMs) have a translucent panel that enables the purchaser to see the product as it is vended. In this type of machine, the product itself is illuminated and used to attract the purchaser’s attention. There are various vending configurations but all machines fit into one of these two categories.



FIGURE 1. EXAMPLES OF COMMON CLOSED-FRONT (LEFT) AND GLASS-FRONT (RIGHT) VENDING MACHINES

Product temperature is an important metric for VMs because customer satisfaction requires proper maintenance of cold products. Ideally, the product temperature located at the next-to-be-vended (NTBV) position should be kept at 36°F. For CFVMs, the NTBV location refers to the bottom position in each of the product stacks (blue in Figure 2

Figure 2, left picture). For GFVMs, the NTBV location refers to the front plane of

product shelving (blue , right picture).

Next-to-be-vended area

FIGURE 2. NEXT-TO-BE-VENDED PRODUCT LOCATION FOR CLOSED-FRONT (LEFT) AND GLASS-FRONT (RIGHT) UNITS

The basic construction of the VMs cabinet is steel with 1.5-inch to 2-inch thick polyurethane insulation surrounding the entire refrigerated cabinet. The following lists the main components of refrigerated VMs:

1. Lights and ballasts

2. Refrigeration system

o Compressor



o Evaporator coil and fan

o Condenser coil and fan

o Expansion device

3. Coin box and vending mechanism

The following describes the main components that are typically found in older generation CFVMs and GFVMs. The lighting system of CFVMs, used to illuminate advertisement panels, consists of two 5 ft. T-12 fluorescent lamps with magnetic ballasts that reside in the doorframe. The lighting system of GFVMs consists of a single 4 ft. T-8 fluorescent lamp with electronic ballasts that reside in the electronics compartment.

Commonly, VMs use refrigerant R-134a. The refrigeration system is served by a small hermetically-sealed reciprocating compressor. These compressors run at a fixed speed without any capacity modulation.

To circulate the air inside the cabinet, the evaporator coil assembly of CFVMs is equipped with two single-speed shaded pole fan motors (Figure 3

Figure 3

, left picture). When the unit is cycled off, however, only one of the evaporator fans continues running while the other is shut off. For space limitations, the evaporator coil assembly of GFVMs uses a single-speed shaded pole fan motor ( , right picture).

FIGURE 3. EVAPORATOR COIL AND FAN FOR CLOSED-FRONT (LEFT) AND GLASS-FRONT (RIGHT)

To reject the refrigeration heat, the condenser coil assembly of VMs uses a single-speed shaded pole fan motor (Figure 4). It is located between the condenser coil and compressor. To control the refrigerant flow through the system, VMs use a capillary tube. Capillary tubes, however, cannot maintain a specified superheat.

Compressor

Fan motor

Condenser coil

FIGURE 4. CONDENSER COIL ASSEMBLY (CONDENSER COIL AND FAN MOTOR)




The operation of the VMs is controlled by a temperature sensor mounted on the evaporator coil. The compressor cycles off when the air temperature reaches the setpoint. These VMs use a mechanical thermostat for setpoint adjustments (Figure 5).

FIGURE 5. TYPICAL MECHANICAL THERMOSTAT FOR VENDING MACHINES

CURRENT ENERGY CODE REQUIREMENTS In August 2009, the United States (US) Department of Energy (DOE) published energy standards for GFVMs (referred to as Class A) and CFVMs (referred to as Class B), which will become effective for VM manufacturers on or after August 31, 2011.1 These maximum daily energy consumption standards are based on the total refrigerated volume for VMs.

Title 20 standards established maximum daily energy consumptions for VMs manufactured on or after January 1, 2006.2 The maximum daily energy consumption is based on the performance of the unit at 90oF ambient temperature, considering thrated capacity, which is the number of 12-ounce cans. Additionally, Title 20 requires VMs to automatically be able to operate at least one of three low-power mode conditions during an inactive period and able to automatically bring itself back to normal operating conditions at the end of the inactivity period. These low-power modes are low lighting power, low refrigeration power, and both low lighting and low refrigeration power. It is noteworthy that this standard is pre-empted by DOE’s standard.

e

The US Environmental Protection Agency (EPA) allows VM manufacturers to attach their ENERGY STAR label under two tiers (Tier I and Tier II) for new or rebuilt models of VM that satisfy maximum daily energy consumption requirements.3 The maximum daily energy consumption for both tiers is a function of vendible capacity, which is the number of 12-ounce cans. The maximum daily energy consumption requirement for Tier I units is the same as Title 20. Similar to Title 20, ENERGY STAR requires VMs to operate at least one of three low-power mode conditions during an inactive period and be able to bring itself back to normal operating conditions at the end of the inactivity period.

Although ENERGY STAR requires VMs to be labeled appropriately as indoor or outdoor, there is no distinction made about the maximum daily energy consumption requirements for indoor or outdoor units. Likewise, Title 20 and US DOE standards do not distinguish between indoor and outdoor units’ maximum daily energy consumption requirements.


DEMAND PROFILE AND ENERGY CONSUMPTION In 2004 and 2005, SCE’s Technology Test Centers (TTC) conducted research projects on older generation CFVMs and GFVMs. Data extracted from those research studies established the power and demand profiles for both types of VMs.4,5

For rating purposes, test protocols require VMs to be tested at 75oF dry bulb (DB) temperature and 45% relative humidity (RH), as well as 90oF DB temperature and 45% RH representing indoor and outdoor conditions, respectively. To quantify impacts of realistic ambient conditions on the performance of VMs, the laboratory testing went beyond the requirements and tested both VMs under additional ambient conditions of 90oF DB/65% RH, 115oF DB/45% RH, and 130oF DB/15% RH. The following sections demonstrate the findings.

Further, to take a conservative approach for establishing demand and energy usage for typical VMs, test data for 90oF DB/45% RH is used. This seems to be a reasonable approach since the outdoor rating conditions are also 90oF DB/45% RH.

GLASS-FRONT VENDING MACHINES SCE’s Technology Test Center’s test data4 revealed that the power demand of the evaporator fans, condenser fan, lighting and money handling mechanism generally did not deviate as the ambient conditions changed (Figure 6). The compressor power demand, on the other hand, showed a noticeable increase as the ambient temperature increased. The total VM used 613 watts at 75°F DB temperature and 45% RH. The power demand was 736 watts at 130°F DB and 15% RH, an overall increase of 123 watts (20%). The compressor was responsible for 75% to 80% of the unit’s total power demand due to operating at elevated head pressures under high ambient temperatures. It is important to note that in this study the adverse energy use impact of solar radiation through the glass was not captured.

462 493 535 586

5449

4949

2829 29

3029

492

565757

57

4848

1818

171717

0

100

200

300

400

500

600

700

800

75°F / 45%RH 90°F / 45%RH 90°F / 65%RH 115°F / 45%RH 130°F / 15%RH

Test Scenarios(glass-front vending machine)

Pow

er U

se b

y C

ompo

nent

Dur

ing

Ref

riger

atio

n Pe

riod

(W)

Compressor Condenser Fan Evaporator Fans Lighting Money Handling Mechanism

Total = 613 W Total = 643 W Total = 688 W Total = 736 W Total = 644 W

FIGURE 6. POWER USE BY COMPONENT FOR EACH AMBIENT CONDITION (GLASS-FRONT UNIT)

As the ambient temperature increased, the refrigeration system had to run for a longer period of time to attempt to satisfy the cooling load (Figure 7). At 130oF DB, the compressor ran just about the entire test period.



22.5

15.3

9.6

23.6

15.5

0

4

8

12

16

20

24



Tota

l Con

dens

ing

Uni

t Run

Tim

eD

urin

g 24

-Hou

r Tes

t (ho

urs)

FIGURE 7. TOTAL REFRIGERATION SYSTEM RUN TIME DURING A 24-HOUR PERIOD (GLASS-FRONT UNIT)

As a result of the increased compressor power demand and refrigeration system run time at higher ambient conditions, the daily energy consumption was increased (Figure 8). The daily energy consumption of the VM increased by 138% as the ambient conditions changed from 75°F DB/45% RH to 130°F DB/15% RH.

4.57.5

12.113.8

7.6

1.281.25

0.880.87

0.55

1.17

1.16

1.15

1.16

1.19

0.68

0.68 0.69

0.71

0.710.42

0.43

0.430.44

0.46

0

4

8

12

16

20



Dai

ly E

nerg

y U

se b

yC

ompo

nent

(kW

h)


Total = 7.3 kWh

Total = 10.8 kWh

Total = 15.6 kWhTotal = 17.4 kWh

Total = 10.7 kWh

FIGURE 8. DAILY ENERGY USE BY COMPONENT FOR EACH AMBIENT CONDITION (GLASS-FRONT UNIT)

CLOSED-FRONT VENDING MACHINES According to TTC’s test data5, power demand of the evaporator fans, condenser fan, lighting and money handling mechanism generally did not deviate as the ambient conditions changed (Figure 9). The compressor power demand, on the other hand, showed a noticeable increase as the ambient temperature increased. The total VM used 589 watts at 75°F DB/45% RH and 702 watts at 130oF DB/15% RH, an overall



increase of 113 watts (19%). The compressor was responsible for 64% to 72% of the unit’s total power demand due to operating at elevated head pressures under high ambient temperatures.

374 394 434508

4046

48

46118 114 114 106

101

402

404141434647

77777

0

100

200

300

400

500

600

700

800


Test Scenarios(closed-front vending machine)

Pow

er U

se b

y C

ompo

nent

Dur

ing

Ref

riger

atio

n Pe

riod

(W)


Total = 589 W Total = 610 W Total = 635 W Total = 702 W Total = 602 W

FIGURE 9. POWER USE BY COMPONENT FOR EACH AMBIENT CONDITION (CLOSED-FRONT UNIT)

As the ambient temperature increased, the refrigeration system had to run for a longer period of time to satisfy the cooling load (Figure 10). At 130oF DB, the compressor did run continuously the entire test period.

23.1

9.97.2

24.0

10.6

0

4

8

12

16

20

24



Tota

l Con

dens

ing

Uni

t Run

Tim

eD

urin

g 24

-Hou

r Tes

t (ho

urs)

FIGURE 10. TOTAL REFRIGERATION SYSTEM RUN TIME DURING A 24-HOUR PERIOD (CLOSED-FRONT UNIT)

As a result of the increased compressor power demand and refrigeration system run time at higher ambient conditions, the daily energy consumption was increased (Figure 11). The daily energy consumption of the VM increased by 150% as the ambient conditions changed from 75°F DB/45% RH to 130°F DB/15% RH.



2.7 3.9

10.012.2

2.842.73 2.73

2.542.42

4.3

0.960.93

0.430.40

0.31

1.11

0.78

0.72

0.79

1.13

0.170.17

0.170.170.17

0

4

8

12

16

20

24



Dai

ly E

nerg

y U

se b

yC

ompo

nent

(kW

h)


Total = 6.7 kWh

Total = 8.4 kWh

Total = 14.8 kWh

Total = 16.9 kWh

Total = 8.0 kWh

FIGURE 11. DAILY ENERGY USE BY COMPONENT FOR EACH AMBIENT CONDITION (CLOSED-FRONT UNIT)

The preceding discussion points out that the demand and energy usage of CFVMs are slightly, but not significantly, lower than that for the GFVMs. The difference is mostly due to higher refrigeration or cooling load for GFVMs. This is because heat can conduct and radiate through the clear glass front panel of GFVMs much easier than through the opaque insulated front panel of CFVMs.

MARKET SIZE The number of VMs in SCE service territory and statewide was provided by SCE’s Measurement and Evaluation Group (Table 2

Table 2

).6 The data provided was based on a 2003 Commercial End-Use Survey (CEUS)7 report. It included the approximate total number of VMs and the total number of GFVMs. Subsequently, the total number of CFVMs was estimated by subtracting the total number of GFVMs from the total number of VMs.

The data shows that the CFVMs have a large presence and make up about 92% of the total units, and the GFVMs make up the remaining 8%. The data, however, does not distinguish between the number of units that are located outdoors or indoors. Since the data is based on a 2003 report and prior to any energy code requirements for VMs, it seems to be reasonable to assume that the number of units provided in represent older generation VMs.

TABLE 2. NUMBER OF CLOSED- AND GLASS-FRONT VENDING MACHINES IN SCE SERVICE TERRITORY AND STATEWIDE

CLASSIFICATIONS OF VENDING MACHINES

NUMBER OF UNITS IN SCE SERVICE TERRITORY

NUMBER OF UNITS STATEWIDE

Closed-front 256,000 734,720

Glass-front 22,000 63,140

Total 278,000 797,860



MARKET BARRIERS The main market barrier for VMs can be associated with the risk of loss of potential sales and unsatisfied customers. These risks should be considered as primary market barriers.

The primary function of VMs is to maintain bottled or canned beverages at a prescribed temperature for purchasing purposes. Therefore, if the VM does not dispense beverages, the customer walks away. Additionally, if the purchased product is above the prescribed temperature this may result in unsatisfied customers.

DEMAND RESPONSE STRATEGIES AND POTENTIAL It is important to note that the following analyses are done for CFVMs only because of their large presence in the market, about 92%. In addition, power demand for a typical CFVM is based on the TTC’s test data under ambient conditions of 90oF DB/45% RH.

There are at least six demand reduction strategies that can be used for CFVMs. Some of the proposed strategies, however, may be more suitable for indoor units than outdoor units, or may require hardware replacement. The following lists all six strategies, which are not in a particular order:

1. Strategy 1: Turn off the entire unit

2. Strategy 2: Turn off the lighting system

3. Strategy 3: Turn off one of the evaporator fan motors

4. Strategy 4: Turn off the lighting system and one of the evaporator fan motors

5. Strategy 5: Reset the temperature setpoint

6. Strategy 6: Reset the temperature setpoint and turn off lighting system

Equation 1 is used to determine the DR potentials associated with the proposed strategies.



STRATEGY 1: TURN OFF THE ENTIRE VENDING MACHINE

STRATEGY DESCRIPTION As its name implies, this strategy shuts off the entire CFVMs. This includes turning off the lighting, refrigeration and money handling mechanisms. This is the simplest strategy and reduces the demand considerably.

TECHNICAL DEMAND REDUCTION It was established that under the ambient conditions of 90oF DB/45% RH, the CFVM uses 602 watts. This includes lighting, refrigeration, and the money handling mechanism. Therefore, turning off these units reduces the demand by 602 watts per CFVM. Table 3 summarizes the anticipated technical demand reduction potential in SCE service territory and statewide for turning off the CFVMs.



TABLE 3. TECHNICAL DEMAND REDUCTIONS IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF THE CLOSED-FRONT VENDING MACHINES

DEMAND

REDUCTION (KW/CFVM

OFF)

MARKET SIZE

IN SCE (NO. OF CFVMS)

TECHNICAL DEMAND

REDUCTION IN SCE (KW)

MARKET SIZE

IN CA (NO. OF CFVMS)

TECHNICAL

DEMAND

REDUCTION IN CA (KW)

0.602 256,000 154,112 734,720 442,301

MARKET ACCEPTANCE A foreseen market barrier to this DR strategy is the loss of sales and unhappy customers. If the CFVMs are not operating, clearly no transaction can occur. For the purpose of this evaluation, market acceptance levels of 1%, 5%, 10%, 20%, and 50% are used.

DEMAND RESPONSE POTENTIAL Table 4 summarizes the results for this strategy based on various market acceptance levels in SCE service territory and statewide. As shown, the demand reductions can range from 1,541 kW to 77,056 kW in SCE’s service territory, and from 4,423 kW to 221,150 kW statewide.

TABLE 4. DEMAND RESPONSE FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF THE CLOSED-FRONT VENDING MACHINES

DR POTENTIAL (KW)

DEMAND

REDUCTION (KW/CFVM

OFF) MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE SCE 256,000 1,541 7,706 15,411 30,822 77,056

0.602 CA 734,720 4,423 22,115 44,230 88,460 221,150

STRATEGY 2: TURN OFF THE LIGHTING SYSTEM

STRATEGY DESCRIPTION As its name implies, this strategy shuts off the lighting system of CFVMs only. In other words, the refrigeration system and money handling mechanism are in operation while the lighting is turned off.

TECHNICAL DEMAND REDUCTION It was established that under the ambient conditions of 90oF DB/45% RH, the CFVM lighting system uses 114 watts. Therefore, only turning off the lighting system reduces the demand by 114 watts per CFVM. Considering the entire 256,000 CFVMs in SCE’s service territory and 734,720 CFVMs statewide, a technical demand reduction potential of 29,184 kW and 83,758 kW, respectively, is anticipated due to turning off the lighting system only, see Table 5.



TABLE 5. TECHNICAL DEMAND REDUCTION IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF THE LIGHTING SYSTEM OF CLOSED-FRONT VENDING MACHINES

DEMAND

REDUCTION (KW /CFVM

LIGHTING)

MARKET SIZE


TECHNICAL

DEMAND


MARKET SIZE


TECHNICAL

DEMAND


0.114 256,000 29,184 734,720 83,758

MARKET ACCEPTANCE Provided that this strategy is implemented during day time periods, there should not be any barriers, or the barriers will be minimal, for this strategy. The fact that lights are turned off, may mislead the potential customers that the VM is not operating, which may result in loss of sales. Nonetheless, for the purpose of this evaluation, market acceptance levels of 1%, 5%, 10%, 20%, and 50% are used.

DEMAND RESPONSE POTENTIAL Table 6

Table 6 summarizes the results for this strategy based on various market acceptance

levels in SCE service territory and California. shows that the demand reductions can range from 292 kW to 14,592 kW in SCE’s service territory, and from 838 kW to 41,879 kW in California.

TABLE 6. DEMAND REDUCTION FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF THE LIGHTING SYSTEM OF CLOSED-FRONT VENDING MACHINES

DR POTENTIAL (KW)

DEMAND

REDUCTION (KW/CFVM

LIGHTING) MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE SCE 256,000 292 1,459 2,918 5,837 14,592

0.114 CA 734,720 838 4,188 8,376 16,752 41,879

STRATEGY 3: TURN OFF ONE OF THE EVAPORATOR FAN MOTORS

STRATEGY DESCRIPTION Since the evaporator coil assembly of CFVMs are equipped with two fan motors, this strategy proposes to shut off one of them. This strategy shuts off one of the evaporator fan motors while the lighting, refrigeration, and money handling mechanism are in operation.

TECHNICAL DEMAND REDUCTION Turning off one of the evaporator fan motors reduces the demand by 23 watts per CFVM. Accordingly, for this strategy, a technical demand reduction potential of 5,888 kW in SCE service territory and 16,899 kW in California is predicted (Table 7).



TABLE 7. TECHNICAL DEMAND REDUCTION IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF ONE OF THE EVAPORATOR FAN MOTORS OF CLOSED-FRONT VENDING MACHINES

DEMAND

REDUCTION (KW /CFVM

EVAP. FAN)

MARKET SIZE


TECHNICAL

DEMAND


MARKET SIZE


TECHNICAL

DEMAND


0.023 256,000 5,888 734,720 16,899

MARKET ACCEPTANCE According to the TTC’s test data, under ambient conditions of 90oF DB/45% RH, turning off one of the evaporator fan motors, at least for a short period of time, will not have an adverse impact on the average product temperatures. The results, however, may vary depending on the ambient conditions where the VM is located. At higher ambient temperatures, shutting off one of the evaporator fan motors may not be a feasible option since it may result in increased product temperature above the desired levels. For the purpose of this evaluation, however, market acceptance levels of 1%, 5%, 10%, 20%, and 50% are used.

DEMAND RESPONSE POTENTIAL Table 8 summarizes the results for this strategy based on various market acceptance levels in SCE service territory and California. It is anticipated that the demand reductions can range from 59 kW to 2,944 kW in SCE service territory, and from 169 kW to 8,450 kW in California.

TABLE 8. DEMAND REDUCTION FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND CALIFORNIA FOR TURNING OFF ONE OF THE EVAPORATOR FAN MOTORS OF CLOSED-FRONT VENDING MACHINES

DR POTENTIAL (KW)

DEMAND

REDUCTION (KW /CFVM

EVAP. FAN) MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE SCE 256,000 59 294 589 1,178 2,944

0.023 CA 734,720 169 845 1,690 3,380 8,450

STRATEGY 4: TURN OFF THE LIGHTING AND ONE OF THE EVAPORATOR FANS

STRATEGY DESCRIPTION This strategy proposes to shut off the lighting system and one of the evaporator fan motors of the CFVMs. In essence, this strategy is the combination of strategies 2 and 3 discussed above.



TECHNICAL DEMAND REDUCTION As discussed in the previous sections, turning off the lighting system reduces the demand by 114 watts, and turning off one of the evaporator fan motors reduces the demand by 23 watts. The combined reduction is 137 watts per CFVM. So, taking into account the entire 256,000 CFVMs in SCE’s service territory and 734,720 CFVMs in California, a technical demand reduction potential of 35,072 kW and 100,657 kW, respectively, is anticipated for this strategy (Table 9).

TABLE 9. TECHNICAL DEMAND REDUCTION IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF THE LIGHTING SYSTEM AND ONE OF THE EVAPORATOR FAN MOTORS OF CLOSED-FRONT VENDING MACHINES

DEMAND

REDUCTION (KW/CFVM

LIGHT & FAN)

MARKET SIZE


TECHNICAL

DEMAND


MARKET SIZE


TECHNICAL

DEMAND


0.137 256,000 35,072 734,720 100,657

MARKET ACCEPTANCE Turning off the lighting may not be a significant barrier for this strategy. Turning off one of the evaporator fan motors for units exposed to hot ambient conditions, however, may have an adverse impact on the product temperatures. To have a general idea about the potential demand reductions, market acceptance levels of 1%, 5%, 10%, 20%, and 50% are used.

DEMAND RESPONSE POTENTIAL Table 10 summarizes the results of this strategy based on various market acceptance levels in SCE service territory and California. As shown, the demand reductions can range from 351 kW to 17,536 kW in SCE service territory, and from 1,007 kW to 50,329 kW in California.

TABLE 10. DEMAND REDUCTION FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND STATEWIDE FOR TURNING OFF THE LIGHTING SYSTEM AND ONE OF THE EVAPORATOR FAN MOTORS OF CLOSED-FRONT VENDING MACHINES

DEMAND REDUCTION (KW)

DEMAND

REDUCTION (KW /CFVM

EVAP. FAN) MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE SCE 256,000 351 1,754 3,507 7,014 17,536

0.137 CA 734,720 1,007 5,033 10,066 20,131 50,329



STRATEGY 5: RESET THE TEMPERATURE SETPOINT

STRATEGY DESCRIPTION The intention of this strategy is to increase the thermostat setpoint in an attempt to cause the refrigeration system to cycle off. Essentially, once the temperature setpoint is satisfied the unit cycles off. This means that the compressor and condenser fan motor will turn off. Accordingly, one of the evaporator fan motors will turn off.

TECHNICAL DEMAND REDUCTION Since increasing the thermostat setpoint causes the compressor, condenser fan motor, and one of the evaporator fan motors to shut off, the demand reduction is the summation of the demand for all three components. At 90oF DB/45% RH, the compressor power demand is 394 watts. The condenser uses 41 watts, and a single evaporator fan motor uses 23 watts at those ambient conditions. Therefore, the combined demand reduction is 458 watts per CFVM. Accordingly, the technical demand reduction potential in SCE service territory would be 117,248 kW and in California 336,502 kW (Table 11).

TABLE 11. TECHNICAL DEMAND REDUCTION IN SCE SERVICE TERRITORY AND CALIFORNIA FOR INCREASING THERMOSTAT SETPOINT OF CLOSED-FRONT VENDING MACHINES

DEMAND

REDUCTION (KW /CFVM

TEMP RESET)

MARKET SIZE


TECHNICAL

DEMAND


MARKET SIZE


TECHNICAL

DEMAND


0.458 256,000 117,248 734,720 336,502

MARKET ACCEPTANCE Increasing the thermostat setpoint is more suitable for the CFVMs that are located in a milder ambient condition such as less than 90oF DB. Since these units are in milder conditions, turning off the refrigeration for a short period of time may not have an adverse impact on the product temperatures. When the DB temperature is above 90oF, this may not be a desirable option. Empirical data shows that at higher ambient DB temperatures these units run almost all the time to maintain the thermostat setpoint. In fact, at higher ambient conditions these units may not even cycle off by increasing the thermostat setpoint. Therefore, the market acceptance levels are dependent on the ambient conditions where the CFVMs are located. To have a general perspective of the potential demand reductions, the market acceptance levels of 1%, 5%, 10%, 20%, and 50% are used.

DEMAND RESPONSE POTENTIAL Table 12 summarizes the results of this strategy in SCE service territory and statewide by considering various market acceptance levels. As illustrated, the demand reductions can range from 1,172 kW to 58,624 kW in SCE service territory. In California, it is anticipated that the demand reductions can range from 3,365 kW to 168,251 kW.



TABLE 12. DEMAND REDUCTION FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND STATEWIDE FOR INCREASING THERMOSTAT SETPOINT OF CLOSED-FRONT VENDING MACHINES


DEMAND

REDUCTION (KW /CFVM

TEMP

RESET) MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE

SCE 256,000 1,172 5,862 11,725 23,450 58,624 0.458

CA 734,720 3,365 16,825 33,650 67,300 168,251

STRATEGY 6: RESET THE TEMPERATURE SETPOINT AND TURN OFF THE LIGHTING

STRATEGY DESCRIPTION This is a combination of strategies 2 and 5. When the thermostat setpoint is increased, the lighting system can be shut off as well.

TECHNICAL DEMAND REDUCTION The potential benefit of increasing the thermostat setpoint is a demand reduction of 458 watts. Turning off the lighting system contributes to a 114 W reduction in demand. When both are implemented, a total of 572 watts reduction in demand can be expected. So, with regards to the entire 256,000 CFVMs in SCE service territory, a demand reduction of 146,432 kW is anticipated for this strategy (So, for this strategy, a technical demand reduction potential of 146,432 kW in SCE service territory and 420,260 kW in California is estimated (Table 13).

TABLE 13. TECHNICAL DEMAND REDUCTION IN SCE SERVICE TERRITORY AND STATEWIDE FOR INCREASING THERMOSTAT SETPOINT AND TURNING OFF THE LIGHTING SYSTEM OF CLOSED-FRONT VENDING MACHINES

DEMAND

REDUCTION (KW/CFVM TEMP

RESET & LIGHT)

MARKET SIZE


TECHNICAL DEMAND


MARKET SIZE


TECHNICAL

DEMAND


0.572 256,000 146,432 734,720 420,260

MARKET ACCEPTANCE Turning off the lighting may not be a significant barrier for this strategy. Adjusting the thermostat setpoint, however, may not be a desirable strategy for CFVMs located in relatively warmer climate zones. For the purpose of this evaluation, the market acceptance levels of 1%, 5%, 10%, 20%, and 50% are used.

DEMAND RESPONSE POTENTIAL Table 14 summarizes the results of this strategy by taking into account various market acceptance levels in SCE service territory and California. As shown, the demand reductions can range from 1,464 kW to 73,216 kW in SCE service territory, and from 4,203 kW to 210,130 kW in California.



TABLE 14. DEMAND REDUCTION FOR VARIOUS MARKET ACCEPTANCE LEVELS IN SCE SERVICE TERRITORY AND STATEWIDE FOR INCREASING THERMOSTAT SETPOINT AND TURNING OFF THE LIGHTING SYSTEM OF CLOSED-FRONT VENDING MACHINES


DEMAND

REDUCTION (KW/CFVM

TEMP RESET

& LIGHT MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE

SCE 256,000 1,464 7,322 14,643 29,286 73,216 0.572

CA 734,720 4,203 21,013 42,026 84,052 210,130

RESULTS This study points out the six different demand response strategies for CFVMs. The study focuses on CFVMs because they constitute about 92% of the market. The analysis relied on laboratory test data to establish the typical power consumption of CFVMs at ambient conditions of 90oF DB temperature and 45% RH. This approach is reasonable and conservative because most of the VMs are located outdoors. Some of the proposed strategies, however, are suitable for the VMs that are located in indoor or are exposed to milder (less than 90oF DB) ambient conditions. For example, increasing the thermostat setpoint (strategies 5 and 6) for the CFVMs that are exposed to above 90oF DB temperatures may not trigger the VMs to cycle off. The empirical data demonstrates that at high ambient conditions although the refrigeration system ran continuously, it was not able to remove heat fast enough to keep the product at the designated temperature of 36oF.

Table 15 summarizes the results for all six strategies. It shows the demand reduction for each of the six strategies per CFVM, and technical demand reduction potential that includes the entire market size in SCE service territory and California. It also shows the DR potential for minimum and maximum market acceptance levels in SCE service territory and California. Obviously, significant demand reductions are attained when the refrigeration system, and more specifically the compressor, of the VMs are turned off (strategies 1, 5, and 6).

TABLE 15. SUMMARY OF PROPOSED STRATEGIES AND THE CORRESPONDING DEMAND REDUCTIONS IN SCE SERVICE TERRITORY AND STATEWIDE

STRATEGIES AND

DESCRIPTION

DEMAND REDUCTION

(KW /CFVM)

TECHNICAL

DEMAND


DEMAND

REDUCTION IN

SCE (KW) [1% TO 50%

MARKET

ACCEPTANCE]

TECHNICAL

DEMAND


DEMAND

REDUCTION IN

CA (KW) [1% TO 50%

MARKET

ACCEPTANCE]

Strategy 1: Turn off the entire unit

0.602 154,112 1,541 to 77,056 442,301 4,423 to 221,150

Strategy 2: Turn off the lighting system

0.114 29,184 292 to 14,592 83,758 838 to 41,879

Strategy 3: Turn off one of the evaporator fan motors

0.023 5,888 59 to 2,944 16,899 169 to 8,450

Strategy 4: Turn off the lighting system and one of the evaporator fan motors

0.137 35,072 351 to 17,536 100,657 1,007 to 50,329




STRATEGIES AND

DESCRIPTION

DEMAND REDUCTION

(KW /CFVM)

TECHNICAL

DEMAND


DEMAND

REDUCTION IN

SCE (KW) [1% TO 50%

MARKET

ACCEPTANCE]

TECHNICAL

DEMAND


DEMAND

REDUCTION IN

CA (KW) [1% TO 50%

MARKET

ACCEPTANCE]

Strategy 5: Reset the temperature setpoint

0.458 117,248 1,172 to 58,624 336,502 3,365 to 168,251

Strategy 6: Reset the temperature setpoint and turn off the lighting system

0.572 146,432 1,464 to 73,216 420,260 4,203 to 210,130

RECOMMENDATIONS It is recommended to evaluate the cost effectiveness of the proposed DR strategies relative to the current measures in energy efficiency rebate programs. Such evaluation will enhance understanding about the value of the proposed DR strategies. Currently, rebate programs offer incentives for using new generation high-efficiency VMs. Clearly, using new generation high-efficiency VMs provides long-term benefits, whereas the DR strategies reduce demand for short periods of time. In addition, the magnitude of the savings realized by using high efficiency VMs are far greater than the savings realized using the proposed DR strategies. It is also necessary to consider the adverse impact of some of the proposed DR strategies on product quality. Specifically, syrup quality of the beverages at higher temperatures can alter taste and subsequently consumers’ acceptance.

In view of DR cost effectiveness, it is also recommended to evaluate the cost effectiveness of targeting either the older and inefficient generation of VMs or the newer and efficient generation of VMs such as ENERGY STAR qualified units. It is anticipated that DR strategies on the older generation of VMs will yield greater demand reductions at higher implementation costs. In contrast, the demand reductions and cost of implementation for newer generation VMs are anticipated to be lower than that for the older generation VMs. Nonetheless, if the proposed DR strategies are pursued, field or laboratory assessment will provide improvement areas for the proposed DR strategies.



REFERENCES

1 United States Department of Energy. 2009. Federal Register Part II. “Energy Conservation Program:

Energy Conservation Standards for Refrigerated Bottled or Canned Beverage Vending Machines; Final Rule.” 10 CFR Part 431. pp. 44914–44924.

2 California Energy Commission. 2007. “2007 Appliance Efficiency Regulations,” CEC-400-2007-016-

REV1. pp. 109-111.

3 Energy Star Program Requirements for Refrigerated Beverage Vending Machines. Retrieved from

http://www.energystar.gov/ia/partners/product_specs/program_reqs/vending_prog_req.pdf.

4 Southern California Edison. 2004. “Performance Evaluation of a Typical Glass-Front Refrigerated

Beverage Vending Machine Under Various Ambient Conditions.”

5 Southern California Edison. 2005. “Performance Evaluation of a Typical Closed-Front Refrigerated

Beverage Vending Machine Under Various Ambient Conditions.”

6 Southern California Edison. 2009. E-mail communication with Measurement and Evaluation Group.

7 California Energy Commission (CEC) California Commercial End-Use Survey (CEUS)

http://www.energy.ca.gov/ceus/index.html, accessed December 2009

http://www.energystar.gov/ia/partners/product_specs/program_reqs/vending_prog_req.pdf



INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR WALK-IN COOLERS AND FREEZERS Phase1: Demand Response Potential

DR 09.05.04 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size......................................

Market Barriers ................................


Results............................................


References ......................................

1

2

7

8

8

15

16

17

Integration of Demand Response Into Title 20 for Walk-In Coolers and Freezers DR 09.05.04


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.04. DES project manager Devin Rauss conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer




ASH Anti-Sweat Heaters

CASE Codes and Standards Enhancement

DOE Department of Energy

DR Demand Response

ECM Electronically Commutated Motor

EPCA Energy Policy and Conservation Act

PSC Permanent Split Capacitor


Title 20 California’s Appliance Energy Efficiency Regulations

Walk-ins Walk-in coolers and walk-in freezers



EXECUTIVE SUMMARY This project seeks to validate and establish the demand response (DR) potential for walk-in coolers and freezers (walk-ins) and to assess the potential for DR capable walk-ins to be included in California’s Appliance Efficiency Regulations (Title 20). This project may follow up with demonstrations of the DR strategies identified, and could ultimately lead to the development of code language, Phases 2 and 3, respectively.

Walk-ins are capable of responding to a DR event by allowing the temperature of the unit to float. This is accomplished through a variety of strategies including cycling, temperature resets, and pre-cooling. The success of each of these strategies is reliant on the amount of float possible, yet there is very little information on this topic. The float is impacted by the strategy, the thermal mass of the unit, and the usage profile. Additionally, walk-ins have the potential to respond to a DR event by reducing evaporator fan speed. Again, the success is dependent on finding the appropriate control strategy to ensure food quality and is dependent on the same variables.

Absent information on the duration of the DR event, the potential for the cycling, temperature reset, and pre-cooling strategies is very similar. The major difference in the pre-cooling strategy is the concern that the refrigerator can be pre-cooled too much, freezing the food and lowering the market acceptance. Evaporator fan speed modulation is expected to have greater market acceptance, as cooling is still provided, yet has less technical potential, reducing the total DR potential. Using the market information and demand profile for each unit, as well as estimates of market acceptance, the total DR potential was determined for each strategy. A summary of the potential within Southern California Edison’s (SCE) service territory, for each strategy, is provided in Table 1.

TABLE 1. DR STRATEGY POTENTIAL SUMMARY

MINIMUM POTENTIAL (KW)

MAXIMUM POTENTIAL (KW)

STRATEGY

SCE CA SCE CA Refrigeration System Cycling 943 1,886 94,273 188,546

Refrigeration System Temperature Reset

1,774 3,548 88,723 177,446

Walk-In Pre-Cooling 1,886 3,772 94,273 188,546

Evaporator Fan Speed Reduction

56 112 2,789 5,578

Table 1 shows that walk-ins present ample opportunity for DR savings. Additionally, SCE is already actively involved in Codes and Standards Enhancement (CASE) studies in an effort to adopt code for walk-ins, both at the state and national levels. Therefore, walk-ins are viable candidates for Phases 2 and 3.

It is recommended that further studies be done to determine the product temperature as a function of time while the unit is off. Also, because Strategies 1, 2, and 3 are similar in nature, (e.g., result in unit shut off), it is recommended that a survey be performed to provide insight into the preferred strategy for the customer. Additionally, it is recommended that a study be performed to optimize the evaporator fan modulation. This includes a similar study of temperature fluctuations, as a function of fan speed and time.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for walk-in coolers and freezers (walk-ins). It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from walk-ins to home office equipment.


Phase 1 of this possible three phase effort addresses the DR potential for walk-ins; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for walk-ins; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for walk-ins.

This report reviews the findings from Phase 1 and estimates the DR potential for walk-ins. This phase entails assessing the demand reduction associated with walk-ins, the population statewide and within SCE service territory, and the market/customer acceptability of DR strategies associated with walk-ins.

TECHNOLOGY DESCRIPTION The Energy Independence and Security Act of 2007 amended the Energy Conservation and Policy Act (EPCA) to establish the code definition of walk-ins. Because this project is aimed at implementing DR into code, the EPCA definition is used. The definition is as follows:

“The terms ‘walk-in cooler’ and ‘walk-in freezer’ mean an enclosed storage space refrigerated to temperatures, respectively, above, and at or below 32 degrees Fahrenheit that can be walked into, and has a total chilled storage area of less than 3,000 square feet.”1

These units can be stand alone (self-contained) wherein the refrigeration system is an integral component of the walk-in. Alternatively, these units can be served by a remote system, typically part of a larger, centralized, refrigeration system and are targeted for inclusion into Title 24 regulation; however all types of walk-ins are considered in this report.

Typically walk-ins consist of the enclosure, with varying levels of insulation, and a refrigeration system which includes the evaporator, condenser, and associated fans, and a mechanism for defrost. Typically the fans are driven by either an Electronically Commutated Motor (ECM) or Permanent Split Capacitor (PSC) motor. The condensers can either be air cooled, incorporating a fan, or water cooled, where a pump is needed.

CURRENT ENERGY CODE REQUIREMENTS Prescriptive requirements for walk-ins are already in place within California and nationwide. Currently, efforts are underway in both arenas to increase the stringency of code. SCE is working on a Codes and Standards Enhancement (CASE) study to



add additional prescriptive measures to Title 20. The DOE is concurrently working on rulemaking that establishes performance based standards for walk-ins. California was given an exemption from the federal standards until a performance based standard is effective, which is targeted for January 1, 2012. Table 2 provides an overview of the current Title 202 and federal standards.1

TABLE 2. CURRENT CODE LEVELS FOR WALK-INS

TITLE 20 FEDERAL STANDARDS Application All Less than 3,000 ft2

Automatic Door Closers

All reach-in doors Main doors: <4’ wide or <7’ tall

Main doors up to 3’9” by 7’

Infiltration Barriers

No requirements Strip doors or spring doors

Insulation Cooler insulation: R-28 Freezer insulation: R-36

Cooler insulation: R-25 Freezer insulation: R-32 Freezer floor insulation: R-28

Motors Evaporator fan motors: Only ECM (as of 1/1/08) Condenser fan motors: ECM, PSC, or 3-phase, or equivalent

Evaporator fan motors: ECM (or equivalent) or 3-phase Condenser fan motors: ECM, PSC, or 3-phase

Lighting No requirements >40 Lumen/W Or must be controlled by occupancy timer

Glass Reach-in doors: Triple pane with heat reflective treated glass or gas fill

Freezers: Triple pane with heat reflective treated glass or gas fill Coolers: Windows in walk-in doors either: • Double pane with heat reflective

treated glass or gas fill, or • Triple pane with heat reflective

treated glass or gas fill.

Glass Anti-Sweat Heaters (ASH)

If no ASH controls, then: • Freezer ASH <40 W/ft of door

width • Cooler ASH <17 W/ft of door

width If ASH controls and higher power than above, then humidity-based controls must be used.

If no ASH controls, then: • Freezer ASH <7.1 W/sq ft of door

area • Cooler ASH <3.0 W/sq ft of door

area If ASH controls and higher power than above, then humidity-based controls must be used.

Defrost No requirements No requirements

DEMAND PROFILE AND ENERGY CONSUMPTION As part of the on-going SCE CASE study, the market size was determined by identifying compressor/condenser sizes and types.3 In order to determine power draw and energy consumption, these same classifications were used. Using the unit conversion factor from horsepower to kW (0.7457 kW/hp), the power draw for each compressor size was determined.

The SCE CASE study also looked at a few typical configurations for walk-ins. From this analysis the fan power was determined. The typical configurations developed a fan power for one, or two in the case of outdoor units, compressor size(s). A fan



power per compressor horsepower multiplier was developed to determine both the condenser and fan power. Equation 1 was used to determine this multiplier.

EQUATION 1. FAN POWER MULTIPLIER

Fan Power Multiplier = (kW FAN, LARGE – kW FAN, SMALL) / (HP LARGE – HP SMALL)

After the multiplier was determined, the incremental fan power was determined for each compressor size, and was added to the base case (1 HP and under) fan power.

It is important to note that the coolers and freezers have different fan requirements which were evidenced in the SCE CASE study, and as a result appear in this study. Additionally, as water-cooled units rely on the movement of liquid rather than air, there is no fan power associated with these condensing units. The pumping power associated with these units could not be found, and as a result is omitted.

Additionally, the SCE CASE study asserts that walk-ins run 18 hours a day.3 This same assumption is used in this report to determine the annual energy consumption.

The results of these various calculations appear in Table 3 and Table 4. Table 3 details the demand and energy for the walk-in coolers. Table 4 provides the same information for walk-in freezers.

TABLE 3. DEMAND PROFILE AND ENERGY CONSUMPTION- WALK-IN COOLER

COMPRESSOR

POWER (KW)

CONDENSER

FAN

POWER

(KW)

EVAPORATOR

FAN POWER

(KW)

TOTAL

REFRIGERATION

POWER (KW)

TOTAL

ENERGY

CONSUMPTION

(KWH/YR) Pre-Charged Unitary

1 HP and under 0.75 0.11 0.08 0.94 6,171

1-1/2 HP 1.11 0.16 0.13 1.41 9,256

2 HP and 2-1/2 HP 1.68 0.24 0.19 2.11 13,884

3 HP 2.23 0.33 0.26 2.82 18,512

3 HP – 15 HP (average 4 HP) 2.98 0.43 0.34 3.76 24,682

Indoor Air-Cooled

1 HP and under 0.75 0.11 0.08 0.94 6,171

1-1/2 HP 1.11 0.16 0.13 1.41 9,256

2 HP and 2-1/2 HP 1.68 0.24 0.19 2.11 13,884

3 HP 2.23 0.33 0.26 2.82 18,512

3 HP – 15 HP (average 4 HP) 2.98 0.43 0.34 3.76 24,682

Outdoor Air-Cooled

1 HP and 0.75 0.07 0.05 0.86 5,673




COMPRESSOR

POWER (KW)

CONDENSER

FAN

POWER

(KW)

EVAPORATOR

FAN POWER

(KW)

TOTAL

REFRIGERATION

POWER (KW)

TOTAL

ENERGY

CONSUMPTION

(KWH/YR) under

1-1/2 HP 1.11 0.11 0.07 1.30 8,509

2 HP and 2-1/2 HP 1.68 0.16 0.11 1.94 12,764

3 HP 2.23 0.21 0.14 2.59 17,019

3 HP – 15 HP (average 4 HP) 2.98 0.28 0.19 3.45 22,692

Water Cooled

1 HP and under 0.75 -- 0.05 0.79 5,212

1-1/2 HP 1.11 -- 0.07 1.19 7,818

2 HP and 2-1/2 HP 1.68 -- 0.11 1.78 11,727

3 HP 2.23 -- 0.14 2.38 15,636

3 HP – 15 HP (average 4 HP) 2.98 -- 0.19 3.17 20,848

Compressor Receiver Units

3 HP – 15 HP (average 4 HP) 2.98 0.28 0.19 3.45 22,692

TABLE 4. DEMAND PROFILE AND ENERGY CONSUMPTION- WALK-IN FREEZER

COMPRESSOR

POWER (KW)

CONDENSER

FAN

POWER

(KW)

EVAPORATOR

FAN POWER

(KW)

TOTAL

REFRIGERATION

POWER (KW)

TOTAL

ENERGY

CONSUMPTION

(KWH/YR) Pre-Charged Unitary

1 HP and under 0.75 0.26 0.12 1.12 7,366

1-1/2 HP 1.11 0.38 0.18 1.68 11,049

2 HP and 2-1/2 HP 1.68 0.57 0.27 2.52 16,574

3 HP 2.23 0.77 0.36 3.36 22,099

3 HP – 15 HP (average 4 HP) 2.98 1.02 0.48 4.48 29,465

Indoor Air-Cooled

1 HP and under 0.75 0.26 0.12 1.12 7,366

1-1/2 HP 1.11 0.38 0.18 1.68 11,049



COMPRESSOR

POWER (KW)

CONDENSER

FAN

POWER

(KW)

EVAPORATOR

FAN POWER

(KW)

TOTAL

REFRIGERATION

POWER (KW)

TOTAL

ENERGY

CONSUMPTION

(KWH/YR) 2 HP and 2-1/2 HP 1.68 0.57 0.27 2.52 16,574

3 HP 2.23 0.77 0.36 3.36 22,099

3 HP – 15 HP (average 4 HP) 2.98 1.02 0.48 4.48 29,465

Outdoor Air-Cooled

1 HP and under 0.75 0.08 0.02 0.84 5,521

1-1/2 HP 1.11 0.11 0.03 1.26 8,281

2 HP and 2-1/2 HP 1.68 0.17 0.04 1.89 12,422

3 HP 2.23 0.23 0.06 2.52 16,562

3 HP – 15 HP (average 4 HP) 2.98 0.30 0.07 3.36 22,083

Water Cooled

1 HP and under 0.75 -- 0.02 0.76 5,020

1-1/2 HP 1.11 -- 0.03 1.15 7,530

2 HP and 2-1/2 HP 1.68 -- 0.04 1.72 11,295

3 HP 2.23 -- 0.06 2.29 15,060

3 HP – 15 HP (average 4 HP) 2.98 -- 0.07 3.06 20,079


3 HP – 15 HP (average 4 HP) 2.98 0.30 0.07 3.36 22,083

MARKET SIZE The market size is determined as part of the on-going SCE CASE study. Although the SCE CASE study is still a draft, the market size data is still used for the purposes of this report. The market data was developed using census data on equipment sales, with extrapolations made to determine the California market size.3 At this point no SCE service territory data has been collected, so an assumption is made that 50% of all walk-ins are within SCE service territory, based on population data. Table 5 details the market size, both statewide and within SCE service territory.


TABLE 5. MARKET SIZE BREAKDOWN

WALK-IN COOLERS WALK-IN FREEZERS TOTAL

Pre-Charged Unitary

Statewide SCE Territory



1 HP and under 991 495 522 261 1,513 756

1-1/2 HP 1,983 991 1,044 522 3,027 1,514

2 HP and 2-1/2 HP 2,478 1,239 1,305 653 3,784 1,892

3 HP 2,478 1,239 1,305 653 3,784 1,892

3 HP – 15 HP (average 4 HP)

1,735 867 914 457 2,648 1,324

TOTAL 9,665 4832 5,091 2,545 14,756 7,378

Indoor Air-Cooled Statewide SCE Territory



1 HP and under 1,983 991 1,044 522 3,027 1,513

1-1/2 HP 3,965 1,982 2,088 1,044 6,054 3,027

2 HP and 2-1/2 HP 4,956 2,478 2,611 1,305 7,567 3,783

3 HP 4,956 2,478 2,611 1,305 7,567 3,783


3,469 1,734 1,827 913 5,297 2,648

TOTAL 19,330 9,665 10,181 5,090 29,511 14,755

Outdoor Air-Cooled




1 HP and under 7,647 3,823 4,028 2,024 11,675 5,837

1-1/2 HP 15,294 7,647 8,056 4,028 23,350 11,675

2 HP and 2-1/2 HP 19,117 9,558 10,070 5,035 29,187 14,593

3 HP 19,117 9,558 10,070 5,035 29,187 14,593


13,382 6,691 7,049 3,524 20,431 10,215

TOTAL 74,558 37,279 39,271 19,635 113,829 56,914

Water Cooled Statewide SCE Territory



1 HP and under 425 212 224 112 649 324

1-1/2 HP 850 425 448 224 1,297 648

2 HP and 2-1/2 HP 1,062 531 559 279 1,622 811

3 HP 1,062 531 559 279 1,622 811


743 371 392 196 1,135 567

TOTAL 4,142 2,071 2,182 1,091 6,324 3,162





3 HP – 15 HP 1,454 727 2,761 1,380 4,216 2,108

TOTALS 110,456 55,228 58,180 29,090 168,636 84,318




MARKET BARRIERS As is the case in all refrigerated food storage applications, the single greatest barrier is food safety and compliance with U.S. Food and Drug Administration (FDA) Food Code which requires all fresh foods be kept below a maximum temperature of 41°F to prevent spoilage.4 It will be required for any DR strategy to maintain this maximum temperature threshold. Additionally, since freezers are also being considered in this report, another market barrier is maintaining the temperature of the food below freezing, 32°F.

DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, the DR potential is defined using Equation 2.



STRATEGY 1 – REFRIGERATION SYSTEM CYCLING

STRATEGY DESCRIPTION This strategy cycles the walk-in’s refrigeration system off for a pre-determined period of time. The amount of cycling influences the duration of the DR event. The lower the amount of cycling is (e.g., 25% as opposed to 75%), the more stable the food temperature is. Similarly to the cycling options offered in the SCE Commercial Summer Discount Plan (100%, 50%, and 30% cycling),5 the cycling/off strategies will evaluate the 100% (off) and 50% (off 15 minutes out of every 30 minutes) cycling options.

TECHNICAL DEMAND REDUCTION For the 100% option, it is assumed that all the power associated with the refrigeration system is shed, while the 50% option results in half of the power being shed. Table 3 and Table 4 detail the demand for the different walk-in coolers and freezers, respectively, and provide the technical demand reduction potential for the 100% option. The demand reduction for the 50% option is equal to half of the values and is shown in Table 6.


TABLE 6. STRATEGY 1- REFRIGERATION SYSTEM CYCLING: TECHNICAL DEMAND REDUCTION (50% OPTION)

COOLER (KW)

FREEZER (KW)

Pre-Charged Unitary

1 HP and under 0.04 0.56

1-1/2 HP 0.065 0.84

2 HP and 2-1/2 HP 0.095 1.26

3 HP 0.13 1.68

3 HP – 15 HP (average 4 HP) 0.17 2.24

Indoor Air-Cooled


1-1/2 HP 0.065 0.84

2 HP and 2-1/2 HP 0.095 1.26

3 HP 0.13 1.68

3 HP – 15 HP (average 4 HP) 0.17 2.24

Outdoor Air-Cooled


1-1/2 HP 0.035 0.63

2 HP and 2-1/2 HP 0.055 0.945

3 HP 0.07 1.26

3 HP – 15 HP (average 4 HP) 0.095 1.68

Water Cooled


1-1/2 HP 0.035 0.575

2 HP and 2-1/2 HP 0.055 0.86

3 HP 0.07 1.145

3 HP – 15 HP (average 4 HP) 0.095 1.53


3 HP – 15 HP (average 4 HP) 0.095 1.68

MARKET ACCEPTANCE

The biggest foreseen acceptance barrier to this DR strategy is compliance with FDA Food Code requirements and the cycling option plays a major role in the ability of the food to maintain temperature and comply with Code. Currently there is no market acceptance data for a DR program leveraging refrigeration system cycling of walk-ins; as a result, estimations were made ranging from 1% to 50% acceptance.



DEMAND RESPONSE POTENTIAL Using Equation 2, the technical potential, market size and breakdown, and various acceptance factors, the DR potential was determined. Table 7 summarizes the potential for the various configurations and provides overall values for coolers, freezers, and the totals within SCE service territory.

TABLE 7. STRATEGY 1 – REFRIGERATION SYSTEM CYCLING DR POTENTIAL

1% ACCEPTANCE

(KW)

5% ACCEPTANCE

(KW)

10% ACCEPTANCE

(KW)

20% ACCEPTANCE

(KW)

50% ACCEPTANCE

(KW)

WALK-IN TYPE

CYCLING OPTION (%) SCE CA SCE CA SCE CA SCE CA SCE CA

100 1,199 2,398 5,994 11,988 11,987 23,974 23,974 47,948 59,935 119,870 Coolers

50 600 1,200 2,997 5,994 5,994 11,988 11,987 23,974 29,968 59,936

100 687 1,374 3,434 6,868 6,868 13,736 13,735 27,470 34,338 68,676 Freezers

50 344 688 1,717 3,434 3,434 6,868 6,868 13,736 17,169 34,338

100 1,886 3,772 9,428 18,856 18,855 37,710 37,709 75,418 94,273 188,546 Totals

50 943 1,886 4,714 9,428 9,428 18,856 18,855 37,710 47,137 94,274

STRATEGY 2 – REFRIGERATION SYSTEM TEMPERATURE RESET

STRATEGY DESCRIPTION The temperature reset strategy for a walk-in relies on raising the thermostat setpoint by a pre-determined value, (e.g., 2°F, 4°F, etc.), during a DR event. Essentially, this results in the refrigeration system being shut off for some period of time, which depends on the temperature reset and the usage of the walk-in.

TECHNICAL DEMAND REDUCTION In line with the demand reduction expectations from a temperature reset strategy in air conditioning applications,6 the temperature reset of the refrigeration system in walk-ins should produce qualitatively similar results. It is assumed that this strategy sheds all power associated with the refrigeration system of the walk-in, except the evaporator fan. The evaporator fan speed is assumed to be maintained in order to provide the design airflow patterns. Table 8 provides the technical demand reduction for the coolers and freezers.



TABLE 8. STRATEGY 2- REFRIGERATION SYSTEM TEMPERATURE RESET: TECHNICAL DEMAND REDUCTION

COOLER (KW)

FREEZER (KW)

Pre-Charged Unitary


1-1/2 HP 1.28 1.50

2 HP and 2-1/2 HP 1.92 2.25

3 HP 2.56 3.00

3 HP – 15 HP (average 4 HP) 3.42 4.00

Indoor Air-Cooled


1-1/2 HP 1.28 1.50

2 HP and 2-1/2 HP 1.92 2.25

3 HP 2.56 3.00

3 HP – 15 HP (average 4 HP) 3.42 4.00

Outdoor Air-Cooled


1-1/2 HP 1.22 1.23

2 HP and 2-1/2 HP 1.84 1.85

3 HP 2.45 2.47

3 HP – 15 HP (average 4 HP) 3.26 3.28

Water Cooled


1-1/2 HP 1.11 1.11

2 HP and 2-1/2 HP 1.68 1.68

3 HP 2.23 2.23

3 HP – 15 HP (average 4 HP) 2.98 2.98


3 HP – 15 HP (average 4 HP) 3.28 3.28

MARKET ACCEPTANCE As noted previously the biggest foreseen acceptance barrier to this DR strategy is compliance with FDA Food Code. The thermostat setpoint of the unit plays a major role in the ability of the food to maintain temperature and comply with Code. Currently there is no market acceptance data for a DR program leveraging temperature reset of walk-ins; as a result estimations were made ranging from 1% to 50% acceptance.




TABLE 9. STRATEGY 2 – REFRIGERATION SYSTEM TEMPERATURE RESET DR POTENTIAL

1% ACCEPTANCE

(KW)

5% ACCEPTANCE

(KW)

10% ACCEPTANCE

(KW)

20% ACCEPTANCE

(KW)

50% ACCEPTANCE

(KW)

WALK-IN TYPE SCE CA SCE CA SCE CA SCE CA SCE CA

Coolers 1,121 2,242 5,604 11,208 11,208 22,416 22,417 44,834 56.042 112,084

Freezers 654 1,308 3,268 6,536 6,536 13,072 13,072 26,144 32,681 65,362

Total 1,774 3,548 8,872 17,744 17,745 35,490 35,489 70,978 88,723 177,446

STRATEGY 3 – WALK-IN PRE-COOLING

STRATEGY DESCRIPTION Pre-cooling relies on advanced notice of a DR event, which would allow for cooling the walk-in to a lower temperature, so the refrigeration system can be shut off, while maintaining an acceptable temperature range, during a DR event. This strategy is best suitable for day-ahead DR events; however, it may also be applicable for day-of events as long as there is sufficient time to properly implement the pre-cooling strategy.

TECHNICAL DEMAND REDUCTION Similar pre-cooling strategy has been used very successfully with air conditioning systems in commercial buildings.7 Clearly, the refrigeration system in walk-ins is not the same application as the air conditioning system in commercial buildings; however, results are expected to be qualitatively comparable. Absent a more detailed analysis of the impact of event duration on the demand reduction, it is assumed that the pre-cooling strategy will shed the power associated with the walk-in refrigeration system for a few hours. Table 3 and Table 4 detail the demand for the different walk-in coolers and freezers, respectively; these values represent the technical demand reduction potential.

MARKET ACCEPTANCE As noted previously the biggest foreseen barrier for acceptance of this DR strategy is compliance with the FDA Food Code. In addition, for walk-in coolers, the pre-cooling can not be done to the point of freezing the food. Currently there is no market acceptance data for a DR program leveraging pre-cooling of walk-ins; as a result, estimations were made ranging from 1% to 50% acceptance.




TABLE 10. STRATEGY 3 – WALK-IN PRE-COOLING DR POTENTIAL

1% ACCEPTANCE

(KW)

5% ACCEPTANCE

(KW)

10% ACCEPTANCE

(KW)

20% ACCEPTANCE

(KW)

50% ACCEPTANCE

(KW)


Coolers 1,199 2,398 5,994 11,988 11,987 23,974 23,974 47,948 59,935 119,870

Freezers 687 1,374 3,434 6,868 6,868 13,736 13,735 27,470 34,338 68,676

Total 1,886 3,772 9,428 18,856 18,855 37,710 37,709 75,418 94,273 188,546

STRATEGY 4 – EVAPORATOR FAN SPEED REDUCTION

STRATEGY DESCRIPTION The evaporator fans in walk-ins are typically always running, and at a constant speed. This strategy reduces the speed of the evaporator fans, thus reducing the associated power draw. This strategy is reliant on the presence of variable speed evaporator fans and associated controller. The strategy employed by the controller can vary; one option is two-speed, wherein the fan runs either at max speed or a reduced speed (or is shut off), alternatively some controllers offer the ability to modulate the fan speed to various levels depending on the load seen by the refrigeration system. Since Title 20 already requires ECM motors on all new walk-ins, it is assumed that by the time this strategy is incorporated into Title 20, a significant portion (40% to 60%) of walk-ins will be capable of evaporator fan speed modulation.

TECHNICAL DEMAND REDUCTION The technical demand reduction is dependent on a minimum allowable fan speed to ensure proper air temperature within the walk-in. The air distribution is dependent on many variables, which in turn, impacts the air temperature within a walk-in. For the purposes of this report, it is assumed that the fan power is halved by this strategy. As noted the amount that the airflow can be reduced is dependent on many factors, this assumption was made to try to reflect the average power reduction, taking into account a range of potential fan speed reductions. The evaporator fan powers are detailed in Table 3 and Table 4, and the reductions are half of the values shown and are presented in Table 11.



TABLE 11. STRATEGY 4- EVAPORATOR FAN SPEED REDUCTION: TECHNICAL DEMAND REDUCTION

COOLER (KW)

FREEZER (KW)

Pre-Charged Unitary


1-1/2 HP 0.065 0.09

2 HP and 2-1/2 HP 0.095 0.135

3 HP 0.13 0.18

3 HP – 15 HP (average 4 HP) 0.17 0.24

Indoor Air-Cooled


1-1/2 HP 0.065 0.09

2 HP and 2-1/2 HP 0.095 0.135

3 HP 0.13 0.18

3 HP – 15 HP (average 4 HP) 0.17 0.24

Outdoor Air-Cooled


1-1/2 HP 0.035 0.015

2 HP and 2-1/2 HP 0.055 0.02

3 HP 0.07 0.03

3 HP – 15 HP (average 4 HP) 0.095 0.035

Water Cooled


1-1/2 HP 0.035 0.015

2 HP and 2-1/2 HP 0.055 0.02

3 HP 0.07 0.03

3 HP – 15 HP (average 4 HP) 0.095 0.035


3 HP – 15 HP (average 4 HP) 0.095 0.035

MARKET ACCEPTANCE Again, the biggest barrier to market acceptance of this DR strategy is compliance with the FDA Food Code. Unlike the first three strategies identified, this strategy still provides cooling to the walk-in, albeit at a reduced rate. The continual cooling should help improve the customer’s perception of this strategy, ultimately leading to greater acceptance. Also, the code requirement of ECM motors will increase market acceptance, as most walk-ins are already physically capable of this strategy, they simply need a controller. Additionally, the potential to have multiple stages of evaporator fan operation could result in greater acceptance. Currently there is no market acceptance data for a DR program leveraging evaporator fan speed reduction



for walk-ins; as a result, estimations were made ranging from 1% to 50% acceptance.

DEMAND RESPONSE POTENTIAL Using Equation 2, the technical potential, market size and breakdown, and various acceptance factors, the DR potential was determined. Table 12 summarizes the potential for the various configurations and provides overall values for coolers, freezers, and the totals.

TABLE 12. STRATEGY 4 – EVAPORATOR FAN SPEED REDUCTION DR POTENTIAL

1% ACCEPTANCE

(KW)

5% ACCEPTANCE

(KW)

10% ACCEPTANCE

(KW)

20% ACCEPTANCE

(KW)

50% ACCEPTANCE

(KW)


Coolers 39 78 196 392 392 784 783 1,566 1,958 3,916

Freezers 17 34 83 166 166 332 333 666 831 1,662

Total 56 112 279 558 558 1,116 1,116 2,232 2,789 5,578

STRATEGY 5 – DEFROST CYCLING

STRATEGY DESCRIPTION Walk-ins are typically defrosted four times a day, on a pre-set schedule six hours apart: midnight, 6:00 A.M., noon, and 6:00 P.M. This scheduling provides a limited peak demand reduction potential given that each defrost cycle typically lasts less than 30 minutes. As a result, this strategy was not investigated further. Although the demand associated with the defrost mechanisms for the different size units is not known, the CASE study provides a range of 3.6 kW up to 21.4 kW, depending on walk-in size.3 Additionally, it is important to note that the defrost mechanisms are present only in the walk-in freezers, further reducing the potential.

RESULTS DR potential for walk-in coolers and freezers range from 56 kW with 1% acceptance when evaporator fan speed is reduced within SCE service territory to 188.546 MW with 50% acceptance for walk-in pre-cooling statewide. Table 13 shows the range of total DR potential for the four strategies identified.


1% ACCEPTANCE (KW)

50% ACCEPTANCE (KW)

STRATEGY

SCE CA SCE CA Refrigeration System Cycling 943 1,886 94,273 188,546

Refrigeration System Temperature Reset

1,774 3,548 88,723 177,446

Walk-In Pre-Cooling 1,886 3,772 94,273 188,546

Evaporator Fan Speed Reduction

56 112 2,789 5,578



RECOMMENDATIONS The DR strategies in this report have not yet been demonstrated to be viable options. However, they rely on the incorporation of known technologies, so it is expected that all four strategies will have a significant demand response potential.

Each of the first three strategies identified has a similar technical potential, as they each result in the refrigeration system being shut off. Where these strategies differ is in the likely amount of time that they will keep the refrigeration system off and their perception of risk to customers. It is recommended that, as a first step, a better understanding of how in the absence of cooling, the temperature of the food product will fluctuate. With this knowledge, the expected duration of time can be determined for each strategy. To address the issue of customer perception, a survey can be performed that addresses the customer’s reaction to a cycling strategy vs. a temperature reset strategy vs. a pre-cooling strategy. This will provide further information to assist in targeting the various strategies.

Strategy 4, evaporator fan speed reduction, is likely to have a greater market acceptance, as cooling is still being provided, yet there are still some unknowns. This strategy will benefit from further investigation and demonstration as it will allow for a better understanding of how the temperature fluctuates as a function of fan speed. It is important to note that variable speed controls is a measure that is proposed as part of the on-going Title 20 CASE study, and can be leveraged to provide further information on this topic.

Strategy 5 offers limited on-peak demand reduction potential and it is not recommended as a stand-alone strategy at this time. However, given the possibility of integrating other DR strategies to walk-ins, this strategy should be revised in the near future.

Again, it is important to note that the aforementioned temperature barriers are set to maintain food quality and any DR strategy that creates unnecessary liability will not be accepted by the market. Additional research is needed to understand the potential temperature impacts.




REFERENCES

1 “Rulemaking Framework for Walk-In Coolers and Walk-In Freezers RIN 1904-AB86,” United States Department of Energy. December 2008. http://www1.eere.energy.gove/buildings/appliance_standards/commercial/wicf_framework_document.html, “Framework Document”

2 California Appliance Energy Efficiency Standards, CEC-400-2006-002-REV2. http://www.energy.ca.gov/2009publications/CED-400-2009-013/CED-400-2009-013.PDF

3 “Analysis of Standards Options for Walk-in Coolers and Freezers,” Draft Report, Southern California Edison, October 2009. (In progress, internal DES document, not publicly available.)

4 “Food and Drug Administration Food Code 2009: Annex 6 – Food Processing Criteria”, US Department of Health and Human Services, 2009. http://www.fda.gov/Food/FoodSafety/RetailFoodProtection/FoodCode/FoodCode2009/ucm188201.htm

5 Southern California Edison, Commercial Summer Discount Plan. http://www.sce.com/summerdiscount/summer-discount-plan-details.htm, accessed on November 23, 2009.

6 Esource, Best Practices in Residential Direct Load Control Programs. November 2006, p. 7. http://esource.com/esource/preview_list/22732?highlight=best%2Cpractices%2Cresidential%2Cdirect%2Cload%2Ccontrol%2Cprograms

7 “Demand Shifting With Thermal Mass in a Large Commercial Building in a California Hot Climate Zone,” Draft Report, Lawrence Berkeley National Laboratory. October 2008. http://www.etcc-ca.com/images/stories/dr_06.08_pre-cooling_strategies_for_dr_in_large_ commercial_buildings.pdf

http://www1.eere.energy.gove/buildings/appliance_standards/commercial/wicf_framework_document.html

http://www1.eere.energy.gove/buildings/appliance_standards/commercial/wicf_framework_document.html

http://www.energy.ca.gov/2009publications/CED-400-2009-013/CED-400-2009-013.PDF

http://www.fda.gov/Food/FoodSafety/RetainFoodProtection/FoodCode/FoodCode2009/ucm188201.htm

http://www.fda.gov/Food/FoodSafety/RetainFoodProtection/FoodCode/FoodCode2009/ucm188201.htm

http://www.sce.com/summerdiscount/summer-discount-plan-details.htm

http://esource.com/esource/preview_list/22732?highlight=best%2Cpractices%2Cresidential%2Cdirect%2Cload%2Ccontrol%2Cprograms

http://esource.com/esource/preview_list/22732?highlight=best%2Cpractices%2Cresidential%2Cdirect%2Cload%2Ccontrol%2Cprograms

http://www.etcc-ca.com/images/storeis/dr_06.08_pre-cooling_strategies_for_dr_in_large_commercial_buildings.pdf

http://www.etcc-ca.com/images/storeis/dr_06.08_pre-cooling_strategies_for_dr_in_large_commercial_buildings.pdf


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR REACH-IN REFRIGERATORS AND FREEZERS Phase1: Demand Response Potential

DR 09.05.05 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size/Barriers .........................


Results............................................


References ......................................

1

2

4

5

9

10

11

Integration of DR into Title 20 for Reach-in Refrigerators and Freezers DR 09.05.05


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.05. DES project manager, Devin Rauss, conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer


Integration of DR into Title 20 for Reach-in Refrigerators and Freezers DR 09.05.05


DOE Department of Energy

DR Demand Response




Integration of Demand Response Into Title 20 for Reach-In Refrigerators and Freezers DR 09.05.05

EXECUTIVE SUMMARY This project assesses the demand response (DR) potential associated with reach-in refrigerators and freezers and the potential to assess the potential for DR capable commercial refrigerators and freezers to be included in California’s Appliance Efficiency Regulations (Title 20). This project may follow up with demonstrations of the DR strategies identified, and could ultimately lead to the development of code language, phases 2 and 3, respectively.

Reach-in refrigerators and freezers are capable of responding to a DR event by allowing the temperature of the unit to float. This can be accomplished through a variety of strategies including cycling, temperature resets, and pre-cooling. The success of each of these strategies is reliant upon the amount of float possible, yet there is very little information on this topic. The float will be impacted by the strategy, the thermal mass of the unit, and the usage profile.

Absent information on the duration of the DR event, the potential for each of these strategies is very similar. The major difference in the pre-cooling strategy is that there is a concern that the refrigerator could be pre-cooled too much, causing the food to freeze and lowering the market acceptance. The total DR potential was determined by using the market information and demand profile for each unit, as well as the estimates of market acceptance. The range of potential, for each strategy, is given in Table 1.




STRATEGY

SCE CA SCE CA Cycling 1,126 2,252 56,275 112,550

Temperature Reset 1,126 2,252 56,275 112,550

Pre-Cooling 1,126 2,252 25,436 50,872

DR for residential refrigerators is a viable option, with manufacturers already working to incorporate the requisite equipment. However, it does not appear to be the same with commercial units. It is recommended that further studies be done to determine the product temperature as a function of time while the unit is off. Also, since these strategies are similar in nature, (e.g., result in unit shut off), it is recommended that a survey be performed to provide insight into the preferred strategy for the customer.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for reach-in refrigerators and freezers. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from home office equipment to reach-in refrigerators and freezers.


Phase 1 of this potential three-phase effort addresses the DR potential for reach-in refrigerators and freezers; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for reach-in refrigerators and freezers; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for reach-in refrigerators and freezers.

This report reviews the findings from Phase 1 and estimates the DR potential for reach-in refrigerators and freezers. This phase entails assessing the demand reduction associated with reach-in refrigerators and freezers, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with reach-in refrigerators and freezers.

TECHNOLOGY DESCRIPTION A reach-in refrigerator or freezer is defined as an upright, refrigerated cabinet with solid or glass doors. Glass door refrigerator/freezers can be used in a variety of settings as either storage or for merchandising, whereas solid door refrigerator/freezers are typically found in commercial kitchens and are used for storage purposes. For the purposes of this report only solid door refrigerator/freezers are investigated.

The cabinet is served by a refrigeration system which can either be self-contained within the unit or located remotely. The units served by the remote condensing unit are assumed to be part of a larger refrigeration system, and thus would be incorporated into the overall commercial refrigeration system, falling under the purview of Title 24. Therefore, only self-contained units are considered in this study.

As noted, this study covers both refrigerators and freezers. However, in a recent rulemaking the Department of Energy (DOE) utilized three product classifications: medium temperature (refrigerator), low temperature (freezer), and ice-cream temperature. This rulemaking covered all commercial refrigeration equipment, yet was driven primarily by the display cases. Given the assumptions noted previously on door types and condensing unit types, the units investigated are not for display purposes, and likely would not operate at the ice-cream temperature. For the purposes of this report, only medium (refrigerator) and low (freezer) temperatures will be considered.



CURRENT ENERGY CODE REQUIREMENTS As previously noted the DOE recently completed rulemaking on commercial refrigeration equipment, which will become effective January 1, 2012. However, this rulemaking did not establish new performance levels for self-contained refrigerators and freezers (only ice-cream temperature and remote condenser units were impacted). As a result, the existing Title 20 code levels remain intact.

As of January 1, 2006, 2005 Title 20 requires that all solid-door, reach-in refrigerators and freezers be manufactured to the ENERGY STAR specification or CEE Tier 1.1 These specifications are shown in Table 2.

TABLE 2. TITLE 20 STANDARDS FOR REACH-IN REFRIGERATORS AND FREEZERS

Equipment Description

California Energy Commission 2005 Title 20 Daily Energy Usage (kWh/day)

Solid-Door Reach-In Refrigerator (CEE Tier 1) ≤ 0.100V†+2.04

Solid-Door Reach-In Freezer (CEE Tier 1) ≤ 0.400V†+1.38

†Where V is the internal volume in ft3.

DEMAND PROFILE AND ENERGY CONSUMPTION In order to determine the energy consumption, a representative size must be determined for these refrigerators and freezers. Based on the assumptions made in the work paper2 associated with this equipment, there are four basic classifications, each of which is given a representative size. The maximum amount of energy consumption allowed by the Title 20 regulations was selected to determine the energy consumption, based on the future nature of incorporating DR into code. Table 3 highlights the classifications, representative sizes and energy consumption for the refrigerators and freezers.

TABLE 3. CLASSIFICATIONS (SIZES) AND ENERGY CONSUMPTION FOR REACH-IN REFRIGERATORS AND FREEZERS

UNDER-COUNTER SINGLE-DOOR DOUBLE-DOOR TRIPLE-DOOR Typical Volume (ft3) 10 24 44 72

Energy Consumption- Refrigerator (kWh/day)

3.04 4.44 6.44 9.24

Energy Consumption- Freezer (kWh/day)

5.38 10.98 18.98 30.18

To determine the demand drawn by these units, specification sheets from various manufacturers were obtained. These provided the voltage and amperage for the various sizes of refrigerators and freezers. Using these values, the power draw was determined. The results of these calculations are shown in Table 4.

TABLE 4. DEMAND DRAWN BY REACH-IN REFRIGERATORS AND FREEZERS

UNDER-COUNTER SINGLE-DOOR DOUBLE-DOOR TRIPLE-DOOR Demand- Refrigerator (kW)

0.414 0.827 1.085 1.360

Demand- Freezer (kW)

0.596 1.192 1.681 2.502



MARKET SIZE As part of this research, no single market study was found that provided figures on the exact number of reach-in refrigerators and freezers in the market. However, 2008 shipment data for ENERGY STAR refrigerators and freezers was found.3 Given the requirement for all equipment sold in California to meet ENERGY STAR standards, it is assumed that the ENERGY STAR data can be interpolated to determine market size. The findings show that 126,000 solid door refrigerators and 67,000 solid door freezers were sold in 2008. Based on commercial energy consumption it is estimated that 9% of all sales are to the state of California. Using this data point 11,340 refrigerators and 6,030 freezers are assumed to enter the market each year. According to the work paper, the use life of this equipment is classified as 12 years; assuming constant annual shipments are made, this leads to a total market size of 136,080 refrigerators and 72,360 freezers in California. Simplistically, it is assumed that SCE’s service territory would have 50% of the market.

In order to use the size classifications identified previously, some assumptions need to be made about the distribution of sizes in the market. It is stated in the work paper that single-door units are the most prevalent, with about twice as many as the double-door units, which are the second most commonly used units. Based on this assertion it is estimated that 50% of the market uses a single-door unit, 25% uses a double-door unit, and under-counter and triple-door units account for 12.5% each. Table 5 details the market size by classification for both SCE service territory and statewide.

TABLE 5. MARKET SIZE BREAKDOWN

TYPE

REGION

UNDER-COUNTER

SINGLE- DOOR

DOUBLE-DOOR

TRIPLE-DOOR

SCE Territory 8,505 34,020 17,010 8,505 Refrigerators

Statewide 17,010 68,040 34,020 17,010

SCE Territory 4,523 18,090 9,045 4,523 Freezers

Statewide 9,045 36,180 18,090 9,045

MARKET BARRIERS As is the case in all refrigerated food storage applications, the single greatest barrier is food safety and compliance with FDA Food Code, which requires that all fresh foods be kept below a maximum temperature of 41°F to prevent spoilage. It will be required for any DR strategy to maintain this maximum temperature threshold. Additionally, since freezers are also being considered in this report, another market barrier is maintaining the temperature of the food to below freezing, 32°F. In either case these temperature barriers are set to maintain food quality and any DR strategy that creates unnecessary liability will not be accepted by the market.



DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, the demand response potential is defined as:



STRATEGY 1 – CYCLING

STRATEGY DESCRIPTION This strategy cycles the refrigerator and freezer on/off for a pre-determined set of time. It requires the installation of communication equipment that is able to receive a signal and in turn respond to it. The amount of cycling influences the duration that the DR event is able to sustain. The lower the amount of cycling, (e.g., 25% as opposed to 75%), the more constant the temperature of the food. However, there is no data currently available on how cycling affects the temperature, so no recommendations can be made on the cycling factor.

TECHNICAL DEMAND REDUCTION Absent an analysis of duration of the event response, it is assumed that this strategy sheds the entire draw of the unit. Table 4 details the demand for the different sizes of refrigerators and freezers: these values are the technical demand reduction potential.

MARKET ACCEPTANCE Foreseen barriers of acceptance for this DR strategy include compliance with FDA food code. The cycling factor plays a major role in the ability of the food to maintain temperature and comply with code, so the amount of cycling also impacts acceptance. Absent an understanding of the cycling, it is estimated that the market acceptance is somewhere between 1 and 50%.



DEMAND RESPONSE POTENTIAL Using Equation 1., the technical potential, market size and breakdown, and various acceptance factors the DR potential was determined. The results of these calculations are shown in Table 6.

TABLE 6. DR POTENTIAL: STRATEGY 1 - CYCLING

1%

ACCEPTANCE (KW)

5%

ACCEPTANCE (KW)

10%

ACCEPTANCE (KW)

20%

ACCEPTANCE (KW)

50%

ACCEPTANCE (KW)

TYPE SIZE

SCE CA SCE CA SCE CA SCE CA SCE CA

Under-counter 35 70 176 352 352 704 704 1,408 1,761 3,522

Single-door 281 562 1,407 2,814 2,813 5,626 5,627 11,254 14,067 28,134

Double-door 185 370 923 1,846 1,846 3,692 3,691 7,382 9,228 18,456

Triple-door 116 232 578 1,156 1,157 2,314 2,313 4,626 5,783 11,566

Ref

riger

ator

s

Total 617 1234 3,084 6,168 6,168 12,336 12,336 24,672 30,839 61,678

Under-counter 27 54 136 272 271 542 543 1,086 1,356 2,712

Single-door 216 432 1,078 2,156 2,156 4,312 4,313 8,626 10,782 21,564

Double-door 152 304 760 1,520 1,520 3,040 3,041 6,082 7,602 15,204

Triple-door 114 228 570 1,140 1,139 2,278 2,278 4,556 5,696 11,392

Free

zers

Total 509 1,018 2,544 5,088 5,087 10,174 10,175 20,350 25,436 50,872

STRATEGY 2 – TEMPERATURE RESET

STRATEGY DESCRIPTION A temperature reset strategy for a refrigerator/freezer relies on raising the thermostat setpoint of the unit to be raised by a pre-determined value, (e.g., 2°F, 4°F, etc.), during a DR event. Essentially, this results in the unit being shut off for some period of time, which depends on the temperature reset and the amount of unit usage. This strategy requires some form of communication equipment that is able to receive and act on a DR event signal.

TECHNICAL DEMAND REDUCTION Absent an analysis of duration of the event response, it is assumed that this strategy sheds the entire draw of the unit. Table 4 details the demand for the different sizes of refrigerators and freezers; these values are the technical demand reduction potential.



MARKET ACCEPTANCE Foreseen barriers of acceptance for this DR strategy include compliance with FDA food code. The thermostat setpoint of the unit plays a major role in the ability of the food to maintain temperature and comply with code, so the change in temperature, (e.g., 2°F vs. 4°F), also impacts acceptance. Absent an understanding of the impact that the temperature reset has on food safety, it is estimated that the market acceptance is somewhere between 1 and 50%.

DEMAND RESPONSE POTENTIAL Using Equation 1, the technical potential, market size and breakdown, and various acceptance factors, the DR potential was determined. The results of these calculations are shown in Table 7.

TABLE 7. DR POTENTIAL: STRATEGY 2 - TEMPERATURE RESET

1%

ACCEPTANCE (KW)

5%

ACCEPTANCE (KW)

10%

ACCEPTANCE (KW)

20%

ACCEPTANCE (KW)

50%

ACCEPTANCE (KW)

TYPE SIZE


Under-counter 35 70 176 352 352 704 704 1,408 1,761 3,522

Single-door 281 562 1,407 2,814 2,813 5,626 5,627 11,254 14,067 28,134

Double-door 185 370 923 1,846 1,846 3,692 3,691 7,382 9,228 18,456

Triple-door 116 232 578 1,156 1,157 2,314 2,313 4,626 5,783 11,566

Ref

riger

ator

s

Total 617 1234 3,084 6,168 6,168 12,336 12,336 24,672 30,839 61,678

Under-counter 27 54 136 272 271 542 543 1,086 1,356 2,712

Single-door 216 432 1,078 2,156 2,156 4,312 4,313 8,626 10,782 21,564

Double-door 152 304 760 1,520 1,520 3,040 3,041 6,082 7,602 15,204

Triple-door 114 228 570 1,140 1,139 2,278 2,278 4,556 5,696 11,392

Free

zers

Total 509 1,018 2,544 5,088 5,087 10,174 10,175 20,350 25,436 50,872



STRATEGY 3 – PRE-COOLING

STRATEGY DESCRIPTION Pre-cooling relies on advanced warning of a DR event to cool the unit to a lower than normal temperature, so it can be shut off in order to maintain the desired temperature during a DR event. In order to accomplish this, a signal is sent well in advance of the event that allows for the unit to initiate the pre-cooling process. Then once the peak demand period is reached, the unit is essentially shut off in order to maintain the original desired setpoint. This strategy would require the incorporation of communicating equipment.

TECHNICAL DEMAND REDUCTION Absent an analysis of duration of the event response, it is assumed that this strategy sheds the entire draw of the unit. Table 4 details the demand for the different sizes of refrigerators and freezers; these values are the technical demand reduction potential.

MARKET ACCEPTANCE Foreseen barriers of acceptance for this DR strategy include compliance with FDA food code. However, another market barrier with pre-cooling is the desired temperature of the food. In the case of a refrigerator it cannot be pre-cooled to the point that the food is frozen.

Similar to the first two strategies, the market acceptance is a function of the ability of food to maintain the temperature during the DR event, yet very little is known about how the food temperature acts during the shut-off period. For a freezer, the same acceptance range, 1-50%, is used. For the refrigerators, the additional barrier of maintaining an above freezing temperature will likely create less market acceptance and therefore is estimated to be between 1 and 20%.



DEMAND RESPONSE POTENTIAL Using Equation 1., the technical potential, market size and breakdown, and various acceptance factors, the DR potential was determined. The results of these calculations are shown in Table 8.

TABLE 8. DR POTENTIAL: STRATEGY 3- PRE-COOLING

1%

ACCEPTANCE (KW)

5%

ACCEPTANCE (KW)

10%

ACCEPTANCE (KW)

20%

ACCEPTANCE (KW)

50%

ACCEPTANCE (KW)

TYPE SIZE


Under-counter 35 70 176 352 352 704 704 1,408 -- --

Single-door 281 562 1,407 2,814 2,813 5,626 5,627 11,254 -- --

Double-door 185 370 923 1,846 1,846 3,692 3,691 7,382 -- --

Triple-door 116 232 578 1,156 1,157 2,314 2,313 4,626 -- --

Ref

riger

ator

s

Total 617 1234 3,084 6,168 6,168 12,336 12,336 24,672 -- --

Under-counter 27 54 136 272 271 542 543 1,086 1,356 2,712

Single-door 216 432 1,078 2,156 2,156 4,312 4,313 8,626 10,782 21,564

Double-door 152 304 760 1,520 1,520 3,040 3,041 6,082 7,602 15,204

Triple-door 114 228 570 1,140 1,139 2,278 2,278 4,556 5,696 11,392

Free

zers

Total 509 1,018 2,544 5,088 5,087 10,174 10,175 20,350 25,436 50,872

RESULTS DR potential for reach-in refrigerators and freezers ranges from 1,126 kW with 1% acceptance, within SCE territory, when the unit is cycled on and off, to 112.55 MW with 50% acceptance for temperature reset statewide. Table 9 shows the range of total DR potential for the three strategies identified.

TABLE 9. RANGE OF TOTAL DR POTENTIAL

1% ACCEPTANCE (KW)

50% ACCEPTANCE (KW)

STRATEGY SCE CA SCE CA Cycling 1,126 2,252 56,275 112,550

Temperature Reset 1,126 2,252 56,275 112,550

Pre-Cooling 1,126 2,252 25,436 50,872



RECOMMENDATIONS The DR strategies in this report have not been demonstrated to be viable options. However, they rely on the incorporation of known technologies, so it is a matter of allocating resources. Each of the strategies identified in this report has a similar technical potential, since each results in the unit being shut off. These strategies differ in the amount of shut-off time of each unit as well as with the customer perception. It is recommended that, as a first step, an understanding of how the temperature of the food product fluctuates in the absence of cooling (unit off). With this knowledge, the duration can be determined for each strategy, and a single strategy can be targeted. To address the issue of customer perception, a survey that addresses the customer’s reaction to a cycling strategy vs. a temperature reset strategy vs. a pre-cooling strategy can be performed. The results of this survey will provide further information to aid in targeting a single strategy.




REFERENCES

1 2005 Appliance Efficiency Regulations, California Code of Regulations (Title 20), page 102. California Energy Commission. April 2005. (http://www.energy.ca.gov/2005publications/CEC-400-2005-012/CEC-400-2005-012.PDF)

2 Work Paper WPSCNRCC0001, “Commercial Foodservice Equipment: Reach-In Refrigerators and Freezers,” Southern California Edison. 2009. (http://eega2006.cpuc.ca.gov/DisplayQuarterlyReport.aspx?ID=7, “SCE Workpapers 2006-2008 part 1.zip”)

3 “Breakdown of 2008 ENERGY STAR Unit Shipment Data,” ICF International. October, 2009.

http://www.energy.ca.gov/2005publications/CEC-400-2005-012/CEC-400-2005-012.PDF

http://www.energy.ca.gov/2005publications/CEC-400-2005-012/CEC-400-2005-012.PDF

http://eega2006.cpuc.ca.gov/DisplayQuarterlyReport.aspx?ID=7


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR COMMERCIAL ICE MACHINES Phase1: Demand Response Potential

DR 09.05.06 Report

Prepared by:


November 30, 2009


Introduction.....................................



Results ...........................................


References ......................................

1

2

5

6

6

7

8

Integration of Demand Response into Title 20 for Commercial Ice Machines DR 09.05.06


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.06. DES project manager Devin Rauss conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES, and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer




ARI Air Conditioning and Refrigeration Institute

CEC California Energy Commission

DR Demand Response

PG&E Pacific Gas and Electric


SDG&E San Diego Gas and Electric




EXECUTIVE SUMMARY This project assesses the demand response (DR) potential associated with commercial ice machines and the potential to include DR capable commercial ice machines in California’s Appliance Efficiency Regulations (Title 20). This project may follow up with demonstrations of the DR strategies identified, and could ultimately lead to the development of code language in phases 2 and 3, respectively.

Ice machines are capable of responding to a DR event by stopping ice production and relying on pre-made ice. Previous work indicates that this is a viable DR strategy. This study looks at the entire population of commercial ice machines, uses market acceptance factors, and determines technical potential to calculate the overall DR potential for commercial ice machines.

This study found that on average a commercial ice machine has the potential to drop load by 2 kW in response to a DR event. This response is possible through implementation of a sensor noting the ice level, the appropriate communication equipment, and the proper control algorithm. Overall, based on this information, and a high market acceptance rate, 180 MW can be reduced within Southern California Edison (SCE) service territory by introducing commercial ice machine DR strategies. Statewide this figure was determined to be 450 MW of DR potential.

This study also shows that the technology currently exists that enables the necessary communication. Although manufacturers do not currently include this equipment in their products, this indicates that, if required, they can. The cost effectiveness was not investigated, but from a purely technological standpoint, this is a viable option for inclusion in Title 20.

This DR strategy works, yet many questions remain. These questions center on what the “critical” ice level is in different applications (how little can they live with), how different classifications of ice machine dictate the “critical” level, and how agreeable manufacturers are to incorporate this equipment in the factory. Further studies on the “critical” ice levels, by end use and ice type, and engagement of manufacturers is recommended.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for commercial ice machines. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to ice machines.


Phase 1, of this potential three-phase effort, addresses the DR potential for commercial ice machines; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for ice machines; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for commercial ice machines.

This report reviews the findings from Phase 1 and estimates the DR potential for ice machines. This phase entails assessing the demand reduction associated with ice machines, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with ice machines.

TECHNOLOGY DESCRIPTION An automatic commercial ice machine is a factory-made assembly (not necessarily shipped in one package) consisting of a refrigeration system, an ice-making mechanism, a water supply system, insulation and a case, as shown in Figure 1. Such a system operates as an integrated unit, used to make and harvest ice. It may also include means for storing and/or dispensing ice. There are three types of ice machines:1

Ice-making head units: Standard ice machines with the ice-making mechanism and the condensing unit in a single package, but with a separate ice storage bin.

Self-contained units: Models in which the ice-making mechanism and the storage compartment are in an integral cabinet.

Remote condensing units: Split-system models in which the ice-making mechanism, the condensing unit, and the ice storage bins are in separate sections.



FIGURE 1. COMMERCIAL ICE MACHINE (ICE MAKING HEAD UNIT TYPE)

Most of the applications use ice-making heads and self-contained units. All Air- Conditioning and Refrigeration Institute (ARI)-certified ice machines use vapor compression refrigeration. About 80% of them have air-cooled integrated condensers, while the rest have either integrated water-cooled condensers or remote air-cooled condensers.

Ice machines can also be classified by the type of ice made:

Cube: clear, regularly shaped ice of a certain weight.

Flake: ice formed into flakes that contain high liquid water contents.

Nugget/Chip: ice made by extruding flake ice into small pieces that are soft for chewing and usually hard enough for dispensing

Crushed: ice that consists of small, irregular pieces made by crushing larger chunks of ice.

These four types of ice are defined based on the ice making process, rather than the ice shape, as their names suggest. The cube type can be cube shaped, or in half cube, cylinder, octagon, or crescent shapes. What they have in common is that they are all made in a process with alternating freezing and harvesting cycles. As a result, cube type ice machines are commonly referred to as batch ice machines.

Cube ice typically has a quality in the range of 95-100%, meaning 95-100% of the water is frozen. Crushed ice is usually made from cube ice; therefore, it has similar ice quality. For both crushed and cube ice, this means that they have a relatively large amount of thermal mass.

Flake type ice and nugget/chip type ice are made continuously with the freezing and harvesting processes occurring at the same time. These ice machines can often be referred to as continuous ice machines. In these machines, the evaporator coil loops around the cylindrical space where liquid water is fed into from the bottom tube. As water freezes into ice, the rotating auger removes the ice from the interior wall and transfers it to the output port at the top. In a flake type machine, this is where the process stops. For a nugget/chip type, the flake ice is pushed through an extruder, compacting the ice into larger pieces; nuggets/chips.

The continuous process leads to lower quality ice, as it does not have as much time to freeze. Typically, flake ice has a quality around 60%-70%. Whereas nugget/cube type will be slightly better due to the compression, and typically ranges from 80%-90%. These types of ice have a relatively small thermal mass, and as a result will degrade quicker.



CURRENT ENERGY CODE REQUIREMENTS As of January 1, 2008, commercial ice machines are regulated by the California Energy Commission (CEC) under Title 20. Table 1 shows the minimum performance levels required by the CEC. Additionally, under the direction of the Energy Policy Act of 2005 the Federal government regulates the performance of ice machines, effective January 1, 2010. It is important to note that the Federal regulations will explicitly apply only to cube type ice machines, whereas the state regulations do not distinguish which types of ice machines are covered. A Codes and Standards Enhancement (CASE) initiative was created to examine the performance of nugget type ice machines, and has been completed. Given the CEC’s priorities for the current rulemaking, this project is not being pursued further at this point.

TABLE 1. CALIFORNIA ENERGY PERFORMANCE STANDARDS FOR ICE MAKERS2

EQUIPMENT

TYPE

TYPE OF

COOLING

HARVEST RATE [H] (LBS ICE/24 HR)

MAXIMUM DAILY

ENERGY USE (KWH/100 LBS ICE)

MAXIMUM DAILY

CONDENSER WATER

USE (GAL/100 LBS ICE)

<500 7.80 - .0055H 200 - .022H

≥500 and <1436 5.58 - .0011H 200 - .022H

Ice-Making Head

Water

≥1436 4.0 200 - .022H

<450 10.26 - .0086H N/A Ice-Making Head

Air

≥450 6.89 - .0011H N/A

<1000 8.85 - .0038H N/A Remote Condensing (but not remote compressor)

Air

≥1000 5.10 N/A

<934 8.85 - .0038H N/A Remote Condensing and Remote Compressor

Air

≥934 5.3 N/A

<200 11.40 - .0190H 191 - .0315H Self-Contained Water

≥200 7.60 191 - .0315H

<175 18.0 - .0469H N/A Self-Contained Air

≥175 9.80 N/A

Similarly, the Environmental Protection Agency (EPA) has ENERGY STAR® labels available for continuous ice machines, but not for batch (nugget and flake type) ice machines. The ENERGY STAR performance criterion also became effective January 1, 2008, and is shown in Table 2.



TABLE 2. ENERGY STAR PERFORMANCE CRITERIA3

EQUIPMENT TYPE

HARVEST RATE [H] (LBS ICE/DAY)

ENERGY USE LIMIT (KWH/100 LBS ICE)

POTABLE WATER

USE LIMIT (GAL/100 LBS ICE)

< 450 9.23 – 0.0077H ≤ 25 Ice Making Head

≥ 450 6.20 – 0.0010H ≤ 25

< 1000 8.05 – 0.0035H ≤ 25 Remote Condensing Unit (without remote condenser) ≥ 1000 4.64 ≤ 25

< 934 8.05 – 0.0035H ≤ 25 Remote Condensing Unit (with remote condenser) ≥ 934 4.82 ≤ 25

< 175 16.7 – 0.0436H ≤ 25 Self Contained Unit

≥ 175 9.11 ≤ 25

DEMAND PROFILE AND ENERGY CONSUMPTION As the components of the various classifications of ice machines are fairly consistent, the load drawn by the units is also fairly consistent. On average a 500-lb ice machine draws over 2 kW of power,4 regardless of type.

Despite the similarities in demand, the various types of ice machines consume noticeably different amounts of energy. This is a result of the aforementioned differences in the ice production process. Since cube type ice machines operate on batch production, they have a reduced run time, resulting in reduced energy consumption. Based on an extrapolation of data presented in the Arthur D. Little report, and conservative ice machine population growth (2% annually), the total consumption for ice makers in California is estimated at 1.07 billion kWh/year. Of this 20% is estimated to be from non-cube type ice machines - with an estimated population of 16,201 machines, this equates to approximately 13,210 kWh/yr per machine. For cube type machines, similar calculations, using a population of 144,757, the average consumption is estimated to be 5,910 kWh/yr per machine.

MARKET SIZE Based on information from the CASE study that established the current Title 20 requirements for commercial ice machines, there are approximately 225,000 ice machines in California.5 Estimates are made that roughly 40% of these ice machines are found in SCE service territory, or 90,000 units.

MARKET BARRIERS A foreseen barrier of acceptance for this DR strategy is ensuring an adequate amount of ice to meet the demand. Any DR strategy for an ice machine can not reduce the production of ice so much that the ice in the storage bin falls below a certain level, which depends on application. Outside of this need to maintain functionality, there are no major food or safety concerns associated with DR strategies for ice machines.



DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, the demand response potential is defined in Equation 1.



STRATEGY 1 – ICE MACHINE SHUT OFF

STRATEGY DESCRIPTION This strategy relies on a signal sent to an ice machine that, depending on current ice storage levels, allows the machine to shut off until the “critical” storage level is reached. A previous study performed by SCE demonstrated the viability of this strategy for commercial ice machines, with a particular focus on customer acceptance.4

TECHNICAL DEMAND REDUCTION As this strategy results in no operation of the ice machine, the entire electrical demand, 2 kW/ice machine, can be saved. The amount of time that the ice machines can be shut off is dependent on the end-use and ice production quality (ice storage time).

MARKET ACCEPTANCE As previously noted the major acceptance barrier is the preservation of functionality. For functionality to be maintained the ice machine must be able to store enough ice to last throughout the DR event, which again depends on the end-use and type of ice. A cube type ice machine is able to be shut off longer as the ice produced can be stored longer without negatively impacting the quality of the ice, when compared to a non-cube type ice machine. However, based on the ability of the machine to “know” the ice storage level, as demonstrated in a previous work,4 it is assumed that acceptance issues can be mitigated resulting in a high market acceptance.

DEMAND RESPONSE POTENTIAL Using Equation 1, the total demand response potential is calculated to be 180 MW within SCE’s territory. Again, this is based on assumptions of 90,000 units, 100% market acceptance, and 2 kW saved per unit. Using the statewide market size of 225,000 machines, the statewide potential is determined to be 450 MW.

RESULTS The strategy identified in this report, ice machine shut off, provides significant DR potential for SCE’s service territory and statewide. Within SCE’s service territory this strategy can reduce load by 180 MW. Statewide this number is 450 MW.



RECOMMENDATIONS The DR strategy identified in this report is already proven to be technically feasible, and based on the savings potential it is recommended that it is further pursued. Recommended next steps include engaging customers to determine what the “critical” ice storage level is for the various end-uses and machine types. Specifically, a study of the DR capability of non-cube type ice machines would be beneficial. Additionally, engagement of manufacturers to incorporate DR-enabling technologies at the point of manufacture is recommended, both to drive cost down and to increase market adoption.


Integration of Demand Response into Title 20 for Commercial Ice Machines DR 09.06.YY06


REFERENCES

1 Little, Arthur D. 1996. “Energy Savings Potential for Commercial Refrigeration Equipment” http://www.lookpdf.com/download-7079-energy-savings-potential-for-commercial-refrigeration-equipment-.html

2 California Appliance Energy Efficiency Standards. CEC-400-2006-002-REV2. http://www.energy.ca.gov/2009publications/CEC-400-2009-013.PDF

3 http://www.energystar.gov/index.cfm?c=comm_ice_machines.pr_crit_comm_ice_machines 4 Southern California Edison. March 2009. “DR 07.07 Demand Response Strategies Using Two-Way

Connectivity for Commercial Ice Machines” (DES Project document, available upon request.) 5 Fernstrom, Gary B. Pacific Gas and Electric. April 2004. “Analysis of Standards Options for

Commercial Packaged Refrigerators, Freezers, Refrigerator-Freezers and Ice Makers” http://www.energy.ca.gov/appliances/archive/2004rulemaking/documents/case_studies/”CASE_Packaged_Refrigeration.pdf

http://www.lookpdf.com/download-7079-energy-savings-potential-for-commercial-refrigeration-equipment-.html

http://www.lookpdf.com/download-7079-energy-savings-potential-for-commercial-refrigeration-equipment-.html

http://www.energy.ca.gov/2009publications/CEC-400-2009-013.PDF

http://www.energystar.gov/index.cfm?c=comm_ice_machines.pr_crit_comm_ice_machines

http://www.energy.ca.gov/appliances/archive/2004rulemaking/documents/case_studies/

http://www.energy.ca.gov/appliances/archive/2004rulemaking/documents/case_studies/


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR HOT FOOD HOLDING CABINETS Phase1: Demand Response Potential

DR 09.05.07 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size/Barrier ...........................


Results ...........................................


References ......................................

1

2

3

4

6

6

7

Integration of DR into Title 20 for Hot Food Holding Cabinets DR 09.05.07


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.07. DES project manager Devin Rauss conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES, and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer


Integration of DR into Title 20 for Hot Food Holding Cabinets DR 09.05.07


DR Demand Response

PG&E Pacific Gas and Electric


SDG&E San Diego Gas and Electric



Integration of Demand Response Into Title 20 for Hot Food Holding Cabinets DR 09.05.07

EXECUTIVE SUMMARY This project assesses the demand response (DR) potential associated with hot food holding cabinets and the potential to include DR requirements for hot food holding cabinets in California’s Appliance Efficiency Regulations (Title 20).

Hot food holding cabinets are capable of responding to a DR event by turning off heating elements. Depending on the configuration of the cabinet, this can result in a complete shut off of the unit, or in reduced heating capacity, if multiple heating elements are present.

The DR potential for hot food holding cabinets is dependent on the strategy selected, market size, and acceptance factors. The strategies suggested have the potential to reduce between 300 and 600 W per cabinet, depending on size and strategy. The statewide market size was determined to be 42,000 units, with roughly 23,000 in Southern California Edison’s (SCE) service territory. Market acceptance is dependent on usage and insulation levels, but is ultimately governed by the need to maintain food quality and safety. The DR potential for the two strategies identified is shown in Table 1.




STRATEGY

SCE CA SCE CA Unit Shut Off 236.5 430 11,825 21,500

Use Staging to Reduce Heating Elements 59.1 107.5 2956.3 5375

This study found that food quality and safety as a function of temperature and time is mostly unknown. However, this is the major driver behind the acceptance of any hot food holding cabinet related DR strategy. Therefore, it is suggested that additional studies be performed to determine this relationship. Additionally, technical feasibility should be demonstrated.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for hot food holding cabinets. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to hot food holding cabinets.


Phase 1 of this potential three-phase effort addresses the DR potential for hot food holding cabinets; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for hot food holding cabinets, and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for hot food holding cabinets.

This report reviews the findings from Phase 1 and estimates the DR potential for hot food holding cabinets. This phase entails assessing the demand reduction associated with hot food holding cabinets, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with hot food holding cabinets.

TECHNOLOGY DESCRIPTION Hot food holding cabinets are electric appliances used in commercial kitchens and food service applications to maintain food temperature prior to serving, after cooking. These appliances are typically highly mobile, and can be transported to various service locations (e.g., a catering company).

According to the California Energy Commission’s 2009 Title 20 appliance regulations, a hot food holding cabinet is defined as:

“a heated, fully enclosed compartment, with one or more solid or partial glass doors, that is designed to maintain the temperature of hot food that has been cooked in a separate appliance. ‘A commercial hot food holding cabinet’ does not include heated glass merchandising cabinets, drawer warmers or cook-and-hold appliances.”1

These cabinets are constructed of a metal exterior and come with either insulated or non-insulated cabinets. The heating is provided by an electric heating element, or multiple elements depending on the size and design. Additionally, these units can be designed to either have a fan circulating air throughout the cabinet, or without the fan. In either case a temperature control mechanism is included. Although these cases come in a variety of sizes, they can be classified into three basic sizes; small, medium, and large.

CURRENT ENERGY CODE REQUIREMENTS Beginning in August 2003, hot food holding cabinets were able to receive the ENERGY STAR® certification. In order to achieve the ENERGY STAR designation these cabinets are required to have an energy usage no greater than 40 W/ft3 in idle mode.



As of January 1, 2006 Title 20 requires that all hot food holding cabinets sold in the state of California meet the same requirements as ENERGY STAR, 40 W/ft3. Although this does not preclude uninsulated holding cabinets from being sold, it greatly shifts the market towards insulated cabinets. There are currently no Federal standards associated with the performance of hot food holding cabinets.

DEMAND PROFILE AND ENERGY CONSUMPTION The performance of these cabinets is highly dependent on the size and insulation level. As noted these units, regardless of insulation level, are required to use no more than 40 W/ft3 in idle mode. Therefore, a performance level of 40 W/ft3 will be used to estimate the demand profile.

Energy consumption is dependent on the run time of these units. Using the same assumptions as the rebate programs,2 the run time is estimated to be 5,475 hours per year.

Additionally, the energy and demand are driven by the size of the unit. The ENERGY STAR website provides a list of qualifying products;3 this list was used to determine three characteristic sizes. For the purposes of this report, these sizes are: small (10 ft3), medium (25 ft3), and large (40 ft3). Table 2 details the demand profile and energy consumption values for these three size cabinets.

TABLE 2. DEMAND PROFILE AND ENERGY CONSUMPTION

EQUIPMENT SIZE DEMAND (KW)

ENERGY CONSUMPTION (KWH)

Small (10 ft3) 400 2190

Medium (25 ft3) 1000 5475

Large (40 ft3) 1600 8760

MARKET SIZE Fisher Nickel Inc. recently commissioned a report on the market size and performance of hot food holding cabinets. Unfortunately, this study is still underway and as a result the report is not public. However, based on their findings to date the total California market size is estimated to be 42,000 units, of which 55%, or roughly 23,000, are within SCE’s service territory.4 Based on the ENERGY STAR list of qualifying products, an estimate of the distribution of sizes was determined. It is estimated that 50% of the units would fall in the medium (25 ft3) range, with 25% in each of the small (10 ft3) and large (40 ft3) ranges.

MARKET BARRIERS Hot food holding cabinets are used to maintain food quality and safety, prior to the food being served. Food quality is a subjective barrier and is dependent on the food type; some food may be better preserved at lower temperatures, while others could require higher temperatures. Food safety is governed by the National Science Foundation (NSF)/ American National Standards Institute (ANSI) Standard 4-2009.5 This standard requires that cooked food be maintained at a minimum of 140°F. However, it does give an allowance that food



may be kept below 140°F for up to 4 hours, which would likely provide enough time to respond to a DR event without jeopardizing food safety. Given this allowance, the market will likely be confined by food quality constraints.

Other barriers that may impact market acceptance rely on understanding the usage profile of the cabinet, (e.g., frequency of openings), and the physical construction, insulated vs. non-insulated. Either factor will impact the ability of the case to maintain temperature, impacting food quality and safety.

DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, the DR potential is defined in Equation 1.



STRATEGY 1 – UNIT SHUT OFF

STRATEGY DESCRIPTION This strategy consists of shutting off the entire hot food holding cabinet during a DR event. This strategy is enabled through communicating technology that receives a signal indicating an event. Additionally, the hot food holding cabinet should have a temperature sensor that determines if the cabinet is operating above the minimum 140°F temperature. Based on the temperature of the holding cabinet, the appliance is able to accept or decline the signal.

TECHNICAL DEMAND REDUCTION As this strategy centers on the shut-off of the entire unit, the demand reduction is equivalent to the power draw of the unit. As noted previously, this is dependent on the size of the cabinet, but using the same assumptions the potential is 400 W, 1000 W, and 1600 W, respectively for the small, medium, and large cabinets.

MARKET ACCEPTANCE Market acceptance of this strategy is governed by the food quality and safety concerns noted previously. It is highly dependent on the usage of the cabinet and insulation level. Given the fact that the peak period corresponds to the period when restaurants are preparing for the dinner rush, it is assumed that cabinet usage is high, and as a result acceptance is low. Estimates for the market acceptance place it between 1% and 50%.

DEMAND RESPONSE POTENTIAL Using Equation 1 the technical demand reduction, market size and breakdown, and various acceptance factors, the DR potential was determined. The results of these calculations are shown in Table 3.



TABLE 3. DR POTENTIAL: STRATEGY 1 - UNIT SHUT OFF

5%

ACCEPTANCE 10%

ACCEPTANCE 20%

ACCEPTANCE

(KW)

50%

ACCEPTANCE 1%

ACCEPTANCE

(KW) (KW) (KW) (KW)

SIZE

SCE CA SCE CA SCE CA SCE CA SCE CA Small (10 ft2) 23.7 43 118.3 215 236.5 430 473 860 1182.5 2150

Medium (25 ft2) 118.3 215 591.3 1075 1182.5 2150 2365 4300 5912.5 10,750

Large (40 ft2) 94.6 172 473 860 946 1720 1892 3440 4730 8600

Total 236.5 430 1182.5 2150 2365 4300 4730 8600 11,825 21,500

STRATEGY 2 – USE STAGING TO REDUCE HEATING ELEMENTS

STRATEGY DESCRIPTION Similar to strategy 1, this strategy would rely on communicating equipment and a temperature sensor to receive and respond to DR events. Rather than turning the entire unit off, this strategy relies upon the fact that some hot food holding cabinets use more than one heating element. This strategy shuts off one, or more, heating elements to reduce the power drawn by the cabinet.

TECHNICAL DEMAND REDUCTION For the purposes of this study, it is assumed that hot food holding cabinets have two evenly-sized heating units. Additionally, it is assumed that each heating element uses ½ the total power drawn by the unit. Based on these assumptions, it is determined that the DR reduction potential ranges from 200 W to 800 W, depending on cabinet size.

MARKET ACCEPTANCE Again, the acceptance of this strategy is governed by the need to maintain food quality and safety. However, as this strategy does not completely eliminate the heating capabilities of the cabinet, the acceptance is estimated to be relatively higher. To be consistent with other strategies, a range of 1% to 50% is used for the market acceptance rate.

DEMAND RESPONSE POTENTIAL Using Equation 1, the technical demand reduction, market size and breakdown, and various acceptance factors, the DR potential was determined. It is important to note that an assumption is made that only 50% of holding cabinets will have multiple heating elements and subsequently be capable of this strategy. The results of these calculations are shown in Table 4.



TABLE 4. DR POTENTIAL: STRATEGY 2 - USE STAGING TO REDUCE HEATING ELEMENTS

1%

ACCEPTANCE

(KW)

5%

ACCEPTANCE (KW)

10%

ACCEPTANCE (KW)

20%

ACCEPTANCE

(KW)

50%

ACCEPTANCE (KW)

SIZE

SCE CA SCE CA SCE CA SCE CA SCE CA Small (10 ft2) 5.9 10.8 29.6 53.8 59.1 107.5 118.3 215 295.6 537.5

Medium (25 ft2) 29.6 53.8 147.8 268.8 295.6 537.5 591.3 1075 1478.1 2687.5

Large (40 ft2) 23.7 43.0 118.3 215 236.5 430 473 860 1182.5 2150

Total 59.1 107.5 295.6 537.5 591.3 1075 1182.5 2150 2956.3 5375

RESULTS DR potential for hot food holding cabinets range from 59.1 kW with 1% acceptance when heating elements are staged within SCE service territory to 21.5 MW with 50% acceptance for unit shut off statewide. Table 5 shows the range of total DR potential for the two strategies identified.


1% ACCEPTANCE (KW)

50% ACCEPTANCE (KW)

STRATEGY

SCE CA SCE CA Unit Shut Off 236.5 430 11,825 21,500

Use Staging to Reduce Heating Elements 59.1 107.5 2956.3 5375

RECOMMENDATIONS For both DR strategies identified, the greatest obstacle for implementation is market acceptance. Market acceptance is driven by food quality and safety, and DR strategies need to be designed to not impact either variable. Therefore, it is recommended that additional studies be performed to better understand the impact that these DR strategies would have on temperature and also what temperatures are required for various end-uses (or food types). Additionally, as these strategies have not been demonstrated previously, it is recommended that a demonstration of technical feasibility be performed.




REFERENCES

1 California Energy Commission. 2009. California Appliance Energy Efficiency Standards, page 52. http://www.energy.ca.gov/2009publications/CEC-400-2009-013/CEC-400-2009-013.pdf

2 Southern California Edison. 2009. Work Paper WPSCNRCC0003, “Insulated Hot Food Holding Cabinets,” http://eega2006.cpuc.ca.gov/DisplayQuarterlyReport.aspx?ID=7, (“SCE Work Papers 2006-2008 part 1.zip”)

3 http://www.energystar.gov/index.cfm?c=hfhc.pr_hfhc 4 Personal communication: e-mail from David Zabrowski, October 7, 2009. 5 NSF/ANSI Standard 4-2009: Commercial Cooking, Rethermalization and Powered Hot Food Holding

and Transportation Equipment. Available for purchase at: http://www.techstreet.com/cgi-bin/detail?doc_no=NSF%7C4_2009&product_id=1650766

http://www.energy.ca.gov/2009publications/CEC-400-2009-013/CEC-400-2009-013.pdf

http://eega2006.cpuc.ca.gov/DisplayQuarterlyReport.aspx?ID=7

http://www.energystar.gov/index.cfm?c=hfhc.pr_hfhc

http://www.techstreet.com/cgi-bin/detail?doc_no=NSF%7C4_2009&product_id=1650766


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR RESIDENTIAL PORTABLE SPAS Phase1: Demand Response Potential

DR 09.05.08 Report

Prepared by:


November 30, 2009

What’s Inside… Executive Summary .........................

Introduction ....................................


DR Strategies and Potential ...............

Results ...........................................

Recommendations............................

References......................................

1

3

4

5

7

7

8

Integration of Demand Response into Title 20 for Residential Portable Spas DR 09.05.08


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.08. DES project manager Angelo Rivera conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer



ABBREVIATIONS AND ACRONYMS DR Demand Response

gpm gallons per minute

V Volume in gallons

ZNE Zero net energy



EXECUTIVE SUMMARY This project seeks to validate and establish the demand response (DR) potential for residential portable spas and to assess the potential for DR capable spas to be included in California’s Appliance Efficiency Regulations (Title 20). This project may follow up with demonstrations of the DR strategies identified, and could ultimately lead to the development of code language, Phases 2 and 3, respectively.

Portable spas main function is to circulate and heat water. This important function is essential in maintaining a set temperature and to keep the spa free of dirt, debris, and bacteria. Annual energy usage data is estimated to be 1,704 kWh using 2004 California Statewide Residential Appliance Saturation Study. Demand is estimated from 1996 Residential Appliance End-Use Study. The maximum demand draw is estimated to be 0.45 kW with appliance diversity (on/off) already taken into account. Market size is estimated using California Statewide Residential Appliance Saturation Study. Southern California Edison (SCE) service territory has over 4.3 million residential customers and it is estimated that 4% of this population owns a spa. Using a 4% ownership rate, there are an estimated 173,000 residential customers who own spas within SCE’s service territory.

Two DR strategies were assessed:

Strategy 1: Portable spa shut off/cycling

Strategy 2: Portable spa temperature reset

Since there is no data on acceptance of a demand response (DR) program for portable spas, estimations were made ranging from 1% to 50% acceptance. It was estimated that both strategies’ maximum DR potential can range from 0.77 to 38 MW depending on market acceptance. Strategy 1 is the quickest and the easiest to accept, due to the fact that it mimics a current DR strategy of AC cycling. Strategy 2 is the best strategy to implement. This strategy allows the customer to choose/experiment with different temperature settings if he is willing to turn down his spa during a DR event. This increases the chance of market acceptance since the customer controls their participation. Both strategies are viable and can be incorporated into Title 20, but controls will have to be incorporated to allow the utility to communicate with the portable spa through its infrastructure. Current spa owners will need a retrofit controls system with the ability to communicate with the utilities’ infrastructure and the ability/smarts to ensure water quality and satisfactory temperature settings.

The strategies identified in this report provide a large opportunity for DR programs in terms of net demand reduction in SCE service territory. Both strategies are candidates likely to incorporate into Title 20 by incorporating/retrofitting controls with the ability to communicate with a utilities’ infrastructure, ensure water quality and desired temperature. Strategy 1 is the quickest to implement a DR program for portable spas due to its ability to mimic a current DR program, air conditioning cycling.

Recommended next steps are to get more detailed data on usage pattern and demand usage for portable spas to fully understand the demand potential. With this data, the large discrepancies between demand draw and demand usage with diversity help to better understand the demand potential. A survey should be done to give feedback on customers’ likeliness to participate in an incentive-based DR program. Also field testing of Strategies 1 and 2 should be initiated to understand each strategy’s impact. This includes working with portable spa manufacturers to promote and develop ZigBee® communications for portable electric spa controls to understand actual demand reduction and to acquire market feedback on strategies currently being employed.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for residential portable spas. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to portable spas.


Phase 1 of this potential three-phase effort addresses the DR potential for portable spas; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for portable spas; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for portable spas.

This report reviews the findings from Phase 1 and estimates the DR potential for portable spas. This phase entails assessing the demand reduction associated with portable spas, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with portable spas.

TECHNOLOGY DESCRIPTION Portable spas’ main functions are to heat and circulate water. These functions are essential in maintaining a set temperature and keeping the spa free of dirt and debris. Typically, portable spas are self-contained, above ground installations consisting of a shell and insulation, hydro jets, filter, pump, and heater as shown in Figure 1. Title 20 Section 1605.3 states “portable electric spa means a factory-built electric spa or hot tub, supplied with equipment for heating and circulating water.”1 Circulation is done by the spa pump. The pump moves water through the skimmer filter to remove debris. The water is then heated to increase water temperature, and returns to the spa. Spa controllers can consist of a timer or a fully digital controller that manages both circulation and heating temperature. Most spas have two to four two-speed pumps that range from 1.5 to 2 horsepower (hp).2 Spas can also have a single-speed circulation pump. The majority of spa heater’s demand draw is in the range of 5.5 to 6 kW.3 Portable spas are available in different sizes (volume), which are directly related to the number of people it can accommodate. Typical sizes range from 3 to 8 people.4 Using the California Energy Commission (CEC) database for portable electric spas, it was found that an average size spa consists of a 400 gallon volume and a 5-person capacity.5 The CEC database lists over 350 spa models from 20 different manufacturers.




FIGURE 1. SPA COMPONENT DIAGRAM

CURRENT ENERGY CODE REQUIREMENTS Title 20, Section 1605.3,6 requires the standby power of portable spas manufactured on or after January 1, 2006, be no greater than 5(V2/3) watts where V is the total spa volume in gallons. There are no federal regulations, ENERGY STAR labeling or Consortium of Energy Efficiency recommendations for residential portable spas.

DEMAND PROFILE AND ENERGY CONSUMPTION Using the 2004 California Statewide Residential Appliance Saturation Study, annual energy usage data is estimated to be 1,704 kWh7 and 2,514 kWh8 statewide and SCE account service territory, respectively. The demand draw from the spa heateestimated to be 5.5 kW. The maximum demand draw includes the circulation and hydro jet pumps. There are typically two ways portable spas are operated. The first is to heat the spa a few hours prior to use; the second is to maintain the spa at a predetermined set point 24-hours a day. The first method requires the heater to be on for several hours until the water temperature reaches its set point. Under this operation there is a higher potential for demand reduction due to the long and continuous use of the heater. Using the latter method, the spa temperature is maintained and the heater cycles on/off. Under this operation the demand reduction potential is lower due to the minimal use of the heater.

r is

Demand profiles for spas can be greatly affected depending on customer operational behavior. Due to the lack of customer behavior information, the average demand draw is estimated from a 1996 Residential Appliance End-Use Study.9 The study estimates portable spa demand with appliance diversity (On/Off) already taken into account to be 0.45 kW. The 24-hour demand profile can be seen in Figure 2 with a peak demand occurring at 1:45 PM. It also shows that a large percentage of spas are turned on during the period of noon to 6 P.M.



FIGURE 2. HOURLY AVERAGE KW DEMAND AND OPERATING PROFILES

MARKET SIZE Market size was estimated using California Statewide Residential Appliance Saturation Study and SCE’s Customer database. Southern California Edison (SCE) service territory has over 4.3 million residential customers10 and it is estimated that 4% of this population11 own portable spas. Using the 4% ownership rate, there are an estimated 173,219 residential customers who own portable spas within SCE service territory.

Overall, California has over 13.312 million residential customers and it is estimated that 4% of this population13 own portable spas. Using the 4% ownership rate, there are an estimated 535,755 residential customers who own portable spas statewide.

MARKET BARRIERS A portable spas’ main function is to circulate and heat water. Customers usually set their spas to run at a certain time in the day so the spa is hot at a pre-determined time. Therefore, the most significant barrier for incorporating DR capabilities into portable spas is hindering a customer’s ability to have the spa hot by a specific time in the day. A secondary barrier is ensuring proper water quality through proper turnover.


DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, it is assumed SCE’s SmartConnect infrastructure is in place and the DR-ready appliance is commercially available. The DR potential is defined in Equation 1.



STRATEGY 1 – PORTABLE ELECTRIC SPA SHUTOFF/CYCLING

STRATEGY DESCRIPTION This strategy relies on a signal being sent to the portable spa to turn off both the pump and heater for a period of time. The period of time depends on the cycling amount from 25% - 100% a customer has chosen. The customer’s ability to choose the cycling of a portable spa during on-peak time, mimics SCE’s current AC cycling program.

TECHNICAL DEMAND REDUCTION With the strategy of forcing both, the pump and heating operational state to Off, a maximum demand reduction of 0.45 kW per unit is expected with the appliance diversity (on/off) already taken into account.

MARKET ACCEPTANCE A foreseen barrier to customer acceptance of this DR strategy is that fact that it hinders the customer’s ability to control the spas’ temperature during a DR event. Customers’ acceptance may be difficult if the customer cannot control their own spa. This inability to have spa-readiness on demand will certainly negatively impact customer satisfaction. A system that gives the customer the ability to override DR events will help DR capabilities be incorporated into Title 20 portable spas. This strategy can be incorporated into Title 20 by adding advanced controls with the ability to interface with a utilities’ infrastructure. This is the quickest strategy to implement and can also encourage retrofits, where controls are added to existing spas. Since there is no market acceptance data for a DR program for portable spas, estimations were made ranging from 1% to 50% acceptance.



DEMAND RESPONSE POTENTIAL Using Equation 1 the total DR potential is calculated and listed in Table 1 for SCE service territory and statewide using varying market acceptance.

TABLE 1 .STRATEGY 1 DEMAND RESPONSE POTENTIAL

DEMAND RESPONSE POTENTIAL (KW) KW

REDUCTION

/UNIT

MARKET SIZE

1% ACCEPTANCE

5% ACCEPTANCE

10% ACCEPTANCE

20% ACCEPTANCE

50% ACCEPTANCE

SCE 173,219 779 3,897 7,795 15,590 38,974 0.45

CA 535,755 2,411 12,054 24,109 48,218 120,545

STRATEGY 2 – PORTABLE ELECTRIC SPA TEMPERATURE RESET

STRATEGY DESCRIPTION This strategy relies on a signal being sent to the spa to decrease its temperature by a certain number of degrees for a period of time. The period of time and the amount of degrees the spa is decreased by is determined by the customer. Portable electric spa reset gives the customer much more flexibility to decide their participation level. The flexibility allows the customer to choose/experiment with different temperature settings. By allowing the customer to experiment with temperature settings, the customer is in control of their participation.

TECHNICAL DEMAND REDUCTION With the strategy of forcing the spas’ operational state to Off by resetting the temperature, it results in a demand reduction of 0.45kW per unit with the appliance diversity, On/Off, already taken into account.

MARKET ACCEPTANCE A foreseen barrier to acceptance of this DR strategy is the fact that it hinders the customer from controlling their spa temperature during a DR event. Customers’ acceptance of a DR program may be difficult if the customer cannot control their spa. Portable spa temperature reset can be an attractive DR strategy for customers. A system that gives customers the ability to choose their participation in a DR event will help DR capabilities be incorporated into portable spas. This strategy allows customers to experiment and try different temperature settings, giving them control of their participation. The range of control can be leveraged on the future plans of a performance-based incentive for a DR program, giving it a larger benefit to be incorporated into Title 20. This strategy can be incorporated into Title 20 by adding advanced controls with the ability to interface with a utilities’ infrastructure. Since there is no market acceptance data for a DR program for portable spas, estimations were made ranging from 1% to 50% acceptance.



DEMAND RESPONSE POTENTIAL Using Equation 1 the total DR potential is calculated and listed in Table 2 for SCE service territory and statewide.

TABLE 2. STRATEGY 2 DEMAND RESPONSE POTENTIAL


REDUCTION

/UNIT MARKET SIZE 1%

ACCEPTANCE 5%

ACCEPTANCE 10%

ACCEPTANCE 20%

ACCEPTANCE 50%

ACCEPTANCE

SCE 173,219 779 3,897 7,795 15,590 38,974 0.45

CA 535,755 2,411 12,054 24,109 48,218 120,545

RESULTS Two DR strategies were assessed:

Strategy 1: Portable spa shutoff/cycling

Strategy 2: Portable spa temperature reset

Since there is no data on acceptance of a DR program for portable spas, estimations were made ranging from 1% to 50% acceptance. It was estimated that both strategy’s maximum DR potential can range from 0.77 to 38 MW depending on market acceptance. Strategy 1 is the quickest and the easiest to accept, due to the fact that it mimics a current DR strategy of AC cycling. Strategy 2 is the best strategy to implement. This strategy allows the customer to choose/experiment with different temperature settings if he is willing to turn down his spa during a DR event. This increases the chance of market acceptance since the customer controls their participation. Both strategies are viable and can be incorporated into Title 20, but controls will have to be incorporated to allow the utility to communicate with the portable spa through its infrastructure. Current spa owners will need a retrofit controls system with the ability to communicate with the utilities’ infrastructure and the ability/smarts to ensure water quality and satisfactory temperature settings.

RECOMMENDATIONS The strategies identified in this report provide a large opportunity for DR programs in terms of net demand reduction in SCE service territory. Both strategies are candidates likely to incorporate into Title 20 by incorporating/retrofitting controls with the ability to communicate with a utilities’ infrastructure, ensure water quality, and desired temperature. Strategy 1 is the quickest to implement a DR program for portable spas due to its ability to mimic a current DR program, AC cycling.

Recommended next steps are to get more detailed data on customer operational behavior to create an average usage pattern and demand profile. By creating usage patterns and demand usage, their data will help to better understand the demand response potential. A survey should be performed to give feedback on customers’ likeliness to participate in an incentive-based DR program. Also field testing of Strategies 1 and 2 should be initiated to understand each strategy’s impact. This includes working with portable spa manufacturers to promote and develop ZigBee® communications for portable electric spa controls to understand actual demand reduction and to acquire market feedback on strategies currently being employed.




REFERENCES

1 California Energy Commission. Appliance Energy Efficiency Regulations (Title 20). December 2006. CEC-400-002-REV2, p. 22.

2 Data obtained from spa specifications provided on manufacturers’ website, which are listed in the CEC database for portable electric spas. http://www.appliances.energy.ca.gov/QuickSearch.aspx



5 California Energy Commission database for portable electric spas, http://www.appliances.energy.ca.gov/QuickSearch.aspx

6 California Energy Commission. Appliance Efficiency Regulations (Title 20). December 2006. CEC-400-2006-002-REV2, p. 119

7 California Statewide Residential Appliance Saturation Study. June 2004. CEC-400-04-009, p. 5 http://websafe.kemainc.com/RASSWEB/uploads/RASS-ExecSummary-FINAL.pdf

8 California Statewide Residential Appliance Saturation Study. June 2004. CEC-400-04-009, p. 4, http://websafe.kemainc.com/RASSWEB/uploads/RASS-ExecSummary-FINAL.pdf

9 1996 Residential Appliance End-use Study. January 1998. P776.320, pg. 6-9, SCE Design and Engineering Services Document Library

10 Southern California Edison Customer Database 11 California Statewide Residential Appliance Saturation Study. June 2004. CEC-400-04-009, p. 4 12 U.S. Census Bureau, California QuickFacts. http://quickfacts.census.gov/qfd/states/06000.html,

accessed on 11/6/09 Population Division 13 California Statewide Residential Appliance Saturation Study. June 2004. CEC-400-04-009, p. 5,

http://websafe.kemainc.com/RASSWEB/uploads/RASS-ExecSummary-FINAL.pdf

http://www.appliances.energy.ca.gov/QuickSearch.aspx







INTEGRATION OF DR INTO TITLE 20 FOR RESIDENTIAL APPLIANCES Phase1: Demand Response Potential

DR 09.05.09 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size......................................

Barriers...........................................


Results............................................


Appendix A ......................................

References ......................................

1

3

8

8

8

13

14

15

19

Integration of DR into Title 20 for Residential Appliances DR 09.05.09


Acknowledgements


Disclaimer



ABBREVIATIONS AND ACRONYMS SCE Southern California Edison

DR Demand Response

AEC Adjusted energy consumption

AV Adjusted Volume

CEE Consortium for energy efficiency

FDA Food and Drug Administration



EXECUTIVE SUMMARY This project seeks to validate and establish the demand response (DR) potential for residential appliances and to assess the potential for DR capable appliances to be included in California’s Appliance Efficiency Regulations (Title 20). This project may follow up with demonstrations of the DR strategies identified, and could ultimately lead to the development of code language, Phases 2 and 3, respectively.

Residential appliances are a combination of food preparation, preservation, and hygiene appliances. Residential appliances are essential items used in an average customer’s home. They account for 32% of a household’s annual energy usage as these appliances consist of a mix of processes and technologies. These processes and technologies include vapor compression cycles, use of heating elements, and motors.

Three demand response strategies were assessed and listed below are the varying results dependent on a 1% to 50% acceptance for SCE service territory and statewide:

Strategy 1: Appliance delayed start/off SCE: Clothes Washers 0.5 to 25 MW

SCE: Clothes Dryers 1.6 to 78 MW

SCE: Dishwashers 1.3 to 65 MW

SCE: Ovens/Ranges 1.3 to 64 MW

SCE: Microwaves 0.8 to 37 MW

CA: Clothes Washers 1.5 to 74 MW

CA: Clothes Dryers 7.7 to 386 MW

CA: Dishwashers 4.1 to 203 MW

CA: Ovens/Ranges 6.2 to 307 MW

CA: Microwaves 2.3 to 114 MW

Strategy 2: Appliance temperature reset/pre-cooling SCE: Refrigerators 9.3 to 464 MW

SCE: Freezers 1.1 to 52 MW

SCE: Water Heaters 0.6 to 30 MW

CA: Refrigerators 28 to 1,413 MW

CA: Freezers 3.8 to 192 MW

CA: Water Heaters 2.6 to 130 MW

Strategy 3: Appliance decreased power settings SCE: Ovens/Ranges 0.6 to 32 MW




SCE: Refrigerators 4.6 to 232 MW






CA: Refrigerators 14 to 707 MW


Since there is no data on acceptance of a DR program for residential appliances, estimations were made ranging from 1% to 50% acceptance. Strategy 1 is expected to have a low acceptance since appliance use is typically needed at the moment of use. Strategy 2 allows the customer to choose/experiment with different temperature settings for a DR event thereby increasing the chance of market acceptance since the customer is in control of his participation. Strategy 3 is expected to have good acceptance for most appliances, as the appliances are still functional, but lower power settings could increase inconvenience to a customer. All strategies are viable to be incorporated into Title 20, but controls will have to be incorporated to allow the utility to communicate to the appliances through its infrastructure.



Recommended next steps include conducting an updated study on appliance load profiles and to survey customers on their likeliness to participate in each of the strategies for incentive based DR programs for their appliances. Field testing of appliance temperature resets and low power setting enabled appliances should also be initiated to understand its impacts. This will include working with different manufacturers to promote and develop ZigBee communications to the appliances controls. A field evaluation would help to understand actual demand reduction and get some market feedback on strategies being employed.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for residential appliances. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to residential appliances.


Phase 1 of this potential three-phase effort addresses the DR potential for residential appliances; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for residential appliances; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for residential appliances.

This report reviews the finings from Phase 1 and estimates the DR potential for residential appliances. This phase entails assessing the demand reduction associated with residential appliances, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with residential appliances.

TECHNOLOGY DESCRIPTION Residential appliances are a combination of food preparation, preservation, and hygiene appliances. Residential appliances are essential items used in an average customer’s home. In California, they account for 32% of a household’s annual energy usage1 as these appliances consist of a mix of processes and technologies. These processes and technologies include vapor compression cycles, use of heating elements, and motors.

Typical residential appliances consist of:

Refrigerator

Freezer

Clothes washer

Clothes dryer

Water heater

Dishwasher

Oven/range

Microwave

CURRENT ENERGY CODE REQUIREMENTS This section covers energy efficiency standards of each appliance. Energy codes being addressed are federal and state as well as ENERGY STAR labeling requirements



and Consortium for Energy Efficiency (CEE) recommended efficiency levels. There are no energy standards for microwaves and ovens/ranges.

There are no current federal or state requirements for incorporation of DR enabling technologies for residential appliances.

REFRIGERATORS

The federal and state requirements for refrigerators are both from the US Department of Energy (DOE) standards specifying maximum adjusted energy consumption (AEC) as a linear function of adjusted volume (AV). The formulas, arranged by product type are listed in Table 1. The ENERGY STAR and CEE requirements are listed below in Table 2.

TABLE 1. FEDERAL STANDARDS FOR REFRIGERATORS

Type Formula

Manual Defrost 8.82AV + 248.4

Partial automatic defrost 8.82AV + 248.4

Automatic defrost, top mounted freezer, no TTD ice 9.80AV + 276

Automatic defrost, side mounted freezer, no TTD ice 4.91AV + 507.5

Automatic defrost, bottom mounted freezer, no TTD ice 4.60AV + 459

Automatic defrost, top mounted freezer, with TTD ice 10.20AV + 356

Automatic defrost, side mounted freezer, with TTD ice 10.10AV + 406

TABLE 2. ENERGY STAR AND CEE REQUIREMENTS FOR REFRIGERATORS

PERCENT ABOVE FEDERAL STANDARD EFFICIENCY LEVEL

COMPACT REFRIGERATORS MID- AND FULL-SIZED

REFRIGERATORS ENERGY STAR 20 20

CEE Tier 1 20 20

CEE Tier 2 25 25

CEE Tier 3 30 30

FREEZER The federal and state requirements for freezers are both from the US DOE standard that specifies maximum AEC as a linear function of AV. The formulas, arranged by product type are listed below in Table 3. There are no CEE levels for freezers, but ENERGY STAR requirements are listed in Table 4.

TABLE 3. FEDERAL STANDARDS FOR FREEZERS

TYPE FORMULA

Upright Freezers with manual defrost 7.55AV + 258.3

Upright Freezers with manual defrost 12.43AV + 326.1

Chest Freezer and all other freezers except Compact Freezers 9.88AV + 143.7

Compact Upright Freezers with manual defrost 9.78AV + 250.8

Compact Upright Freezers with manual defrost 11.40AV + 391



TYPE FORMULA

Compact Chest Freezers 10.45AV + 152

TABLE 4. ENERGY STAR REQUIREMENT FOR FREEZERS

EQUIPMENT VOLUME CRITERIA

Full Size Freezer 7.75 Cubic feet or greater At least 10% more energy efficient than the minimum federal government standard (NAECA)

Less than 7.75 cubic feet and 36 inches or less in height

Compact Size Freezer At least 20% more energy efficient than the minimum federal government standard (NAECA)

CLOTHES WASHER The federal and state requirements for clothes washers are both from the DOE standards specifying a modified energy factor (MEF) and water factor (WF). MEF is a combination of energy factor and remaining moisture content. It indicates how many cubic feet of laundry can be washed and dried with one kWh. WF is the number of gallons needed for each cubic foot of laundry. Table 5 lists the federal standards, ENERGY STAR and CEE requirements for clothes washers.

TABLE 5. FEDERAL STANDARDS AND ENERGY STAR AND CEE REQUIREMENTS FOR CLOTHES WASHERS

LEVEL MODIFIED ENERGY FACTOR

(MEF) WATER FACTOR (WF)

Federal Standard 1.26 No Requirements

ENERGY STAR 1.80 7.5

CEE Tier 1 1.80 7.5

CEE Tier 2 2.00 6.0

CEE Tier 3 2.20 4.5

CLOTHES DRYER The federal and state requirements for clothes dyers are both from the DOE standards specifying a minimum energy factor (lbs/kWh). There are no CEE or ENERGY STAR requirements for clothes dryers. Table 6 lists the federal standards for clothes dryers.

TABLE 6 . STANDARDS FOR CLOTHES DRYERS

APPLIANCE MINIMUM ENERGY FACTOR (LBS/KWH)

Electric, standard clothes dryer 3.01

Electric, compact, 120 volt clothes dryer 3.13

Electric, compact, 240 volt clothes dryer 2.67



WATER HEATER The federal and state requirements for water heaters are both from the DOE standards specifying a maximum input rating, input to volume ratio, minimum thermal efficiency, and minimum standby loss. There are no CEE or ENERGY STAR standards for water heaters. Table 7 lists the federal standards for water heaters.

TABLE 7. STANDARDS FOR WATER HEATERS

FUEL INPUT

RATING VOLUME

(GALLONS)

INPUT TO VOLUME

RATIO

(BTU/GAL)

MINIMUM

THERMAL

EFFICIENCY (%)

MINIMUM

STANDBY LOSS

(%HOUR) Electric >12 kW ≤140 <4,000 Not Applicable 0.3 +27/V

Electric >12 kW >140 <4,000 Not Applicable 0.3 +27/V

Electric >12 kW <10 ≥4,000 80 Not Applicable

Electric >12 kW ≥10 ≥4,000 77 2.3 + 67/V

DISHWASHERS The federal and state requirements for dishwashers are both from the DOE standards specifying a minimum energy factor, maximum kWh/year, and a maximum gallons/cycle. Table 8 lists the federal standard, ENERGY STAR and CEE requirements for clothes washers.

TABLE 8 . STANDARDS FOR DISHWASHERS

EFFICIENCY LEVEL

MINIMUM ENERGY FACTOR

MAXIMUM KWH/YEAR

MAXIMUM GALLONS/CYCLE

Standard-Size Dishwasher (holds eight or more place settings)

Federal Standard 0.46 No Requirement No Requirement

ENERGY STAR No Requirement 324 5.8

CEE Tier 1 0.72 307 5.0

CEE Tier 2 0.25 295 4.25

Compact Dishwasher (holds fewer than eight place settings)

Federal Standard 0.46 No Requirement No Requirement

ENERGY STAR No Requirement 234 4.0

CEE Tier 1 1.0 222 3.5



DEMAND PROFILE AND ENERGY CONSUMPTION Annual energy usage data was estimated for each appliance by using California Statewide Residential Appliance Saturation Study. Demand was taken from the 1996 Residential Appliance End Use Study.2 Average demand already takes into account for appliance diversity (On/Off). Table 9 lists the different appliances’ energy and demand values.

TABLE 9. APPLIANCE ENERGY CONSUMPTIONS

APPLIANCE KWH KW APPLIANCE PEAK USAGE

Refrigerator 801 0.18 relatively constant through the day Second Refrigerator 1,210 n/a relatively constant through the day Freezer 983 0.16 relatively constant through the day Clothes Washer 129 0.018 12PM Clothes Dryer 717 0.2 5PM Water Heater 2342 0.28 12PM Dishwasher 80 0.05 5PM Oven/Range 271 0.11 4PM Microwave 139 0.018 used mostly during mid and off peak

Current data provided by Whirlpool Corporation highlight three appliances.3 These three appliances are a clothes washer, dishwasher, and refrigerator. Clothes dryers’ peak demand is about 5.5 kW as shown in the example in Figure 1. For dishwashers, the peak demand is 1.2 kW during the water heating portion of its cycle. For refrigerators, the peak demand is about 575 watts during the defrost cycle. Also with refrigerators there is another larger demand of near 400 watts during the ice making process. The peak demand is highlighted for each appliance to show there is a higher DR potential for each one. Appendix A, Figures 2 thru 9, shows the 24-hour demand profiles for each appliance from the 1996 Residential Appliance End Use Study.

FIGURE 1. DRYER LOAD PROFILE



MARKET SIZE Market size is estimated using 2004 California Statewide Residential Appliance Saturation Study (RASS). SCE service territory has over 4.3 million residential customers4 and statewide there are over 13.3 million residential customers.5 Appliance saturation percentages were also taken from the RASS data6 and applied to the population to calculate appliance market size. Table 10 lists each appliances market size for SCE service territory and statewide.

TABLE 10. APPLIANCE MARKET SIZE

SCE CALIFORNIA APPLIANCE RESIDENTIAL

CUSTOMERS APPLIANCE

SATURATION APPLIANCE

MARKET SIZE RESIDENTIAL CUSTOMERS

APPLIANCE SATURATION

APPLIANCE MARKET SIZE

Refrigerator 4,330,670 100% 4,330,670 13,308,346 100% 13,308,346

Second Refrigerator 4,330,670 19% 822,827 13,308,346 18% 2,395,502

Freezer 4,330,670 15% 649,601 13,308,346 18% 2,395,502

Clothes Washer 4,330,670 77% 3,334,616 13,308,346 74% 9,848,176

Clothes Dyer 4,330,670 18% 779,521 13,308,346 29% 3,859,420

Water Heater 4,330,670 5% 216,534 13,308,346 7% 931,584

Dishwasher 4,330,670 60% 2,598,402 13,308,346 61% 8,118,091

Oven/Range 4,330,670 27% 1,169,281 13,308,346 42% 5,589,505

Microwave 4,330,670 96% 4,157,443 13,308,346 95% 12,642,929

MARKET BARRIERS The biggest market barrier is the customer’s demand for the appliance. When a customer uses an appliance its function is usually needed at the exact time it is used. Delaying appliance usage or its full functionality usually is not acceptable to the customer. There may be times an appliance function is not needed at a specific time and in those cases delayed start or decreased appliance functionality is a viable option. Another big market barrier is food safety, particularly with refrigerators and freezers. There are no code requirements for refrigerator and freezer temperatures since customers can control their own temperatures. However, the suggested temperatures come from the Food and Drug Administration (FDA). The FDA Food Code for commercial sector requires that all fresh foods be kept at a maximum temperature of 41°F to prevent spoilage and growth of food-borne illnesses.7 Customers are not willing to relinquish control of their appliances if temperature limits are not within their control.

DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, it is assumed SCE’s SmartConnect infrastructure is in place and the DR-ready appliance is commercially available. The DR potential is defined using Equation 1.





STRATEGY 1 – APPLIANCE DELAYED START/OFF

STRATEGY DESCRIPTION Delaying the start of an appliance can be applied to a clothes washer, clothes dryer, dishwasher, oven/range, and microwave. This strategy relies on a signal being sent to the appliance, which would shut off for a period of time or delay its start to an off- peak time.

TECHNICAL DEMAND REDUCTION By forcing the appliance to “Off,” or to delay its start, the maximum demand reduction is the whole demand draw of the appliance. Table 11 lists each appliances demand reduction with appliance diversity (On/Off) taken into account.

TABLE 11. APPLIANCE DEMAND REDUCTION FOR STRATEGY 1

APPLIANCE DEMAND REDUCTION (KW)

Clothes Washer 0.015

Clothes dryer 0.2

Dishwasher 0.05

Oven/Range 0.11

Microwave 0.018

MARKET ACCEPTANCE A foreseen market barrier to acceptance of this DR strategy is the customer’s demand for appliance usage. When a customer uses an appliance its function is usually needed at that exact moment. Delaying a customer’s ability to clean clothes or prepare food is not acceptable. There are times when an appliance is not needed at a specific time, and in those cases a delayed start is a viable option. Added hardware will need to be put into place in order for the customer to comfortably incorporate DR into their system. This added hardware will need to be an interface for the customer to understand their appliance usage and the monetary impact if used at a certain high peak time. This DR strategy will have a difficult acceptance without the proper education on the utilities’ needs and the customers’ benefits. This type of strategy needs to be a performance-based incentive as customers are likely to override a DR event often. Overall, the acceptance of this strategy should be low and proper technology and control would need to be given to the market. This strategy may have a long adoption time due to the manufacturer’s need to develop and incorporate an interface and controls for a smart appliance. Since there is no market acceptance data for a DR program for residential appliances, estimations are made ranging from 1% to 50% acceptance.




TABLE 12. STRATEGY 1 - DEMAND RESPONSE POTENTIAL

DEMAND RESPONSE POTENTIAL (KW) KW REDUCTION /UNIT

MARKET SIZE 1% ACCEPTANCE

5% ACCEPTANCE

10% ACCEPTANCE

20% ACCEPTANCE

50% ACCEPTANCE

Clothes Washers

SCE 3,334,616 500 2,501 5,002 10,004 25,010 0.015

CA 9,848,176 1,477 7,386 14,772 29,545 73,861

Clothes Dryers

SCE 779,521 1,559 7,795 15,590 31,181 77,952 0.2

CA 3,859,420 7,719 38,594 77,188 154,377 385,942

Dishwashers

SCE 2,598,402 1,299 6,496 12,992 25,984 64,960 0.05

CA 8,118,091 4,059 20,295 40,590 81,181 202,952

Ovens/Ranges

SCE 1,169,281 1,286 6,431 12,862 25,724 64,310 0.11

CA 5,589,505 6,148 30,742 61,485 122,969 307,423

Microwave

SCE 4,157,443 748 3,742 7,483 14,967 37,417 0.018

CA 12,642,929 2,276 11,379 22,757 45,515 113,786

STRATEGY 2 – APPLIANCE TEMPERATURE RESET/PRE-COOLING

STRATEGY DESCRIPTION Temperature resetting of appliances can be incorporated into refrigerators, freezers, and water heaters. The strategy leverages residential appliance thermostats to change their setpoints. The setpoints are set lower for refrigerators and freezers and higher for water heaters. When the DR event occurs, the temperature is reset higher or lower to allow the appliances to float to the new setpoint. With this strategy a day-ahead DR signal will have to be sent to the appliance. Appliance temperature resets give the customer much more flexibility to decide their participation level. The flexibility also allows the customer to choose/experiment with different temperature range settings. By allowing the customer this type of flexibility, the customer is in control of their participation during a DR event. This strategy is favorable as it falls in line with future plans to pay DR incentives on performance.



TECHNICAL DEMAND REDUCTION By forcing the appliance to off through a temperature reset, the maximum demand reduction is the whole demand draw of the appliance. Table 13 lists each appliances demand reduction with appliance diversity (On/Off) taken into account.

TABLE 13. APPLIANCE DEMAND REDUCTION

Appliance Demand Reduction (kW)

Refrigerator 0.18

Freezer 0.16

Water Heater 0.28

MARKET ACCEPTANCE A foreseen market barrier to this DR strategy is food safety for both the refrigerator and freezer. Customers are unwilling to allow the utility to decrease and raise their food storage appliance setpoints. A customer currently has the ability to control their own refrigerator setpoint. To raise market acceptance, the strategy would give the customer’s the ability to experiment and try different temperature range settings, thus giving the customers control of their participation. The range of control can be leveraged for future plans of a performance-based incentive DR program. Appliance temperature reset is an attractive DR strategy for customers. Once again, education is key to the success of this strategy as it helps customers understand demand reduction and how it affects their appliances and their utility fees. Since there is no market acceptance data for a DR program for residential appliances, estimations are made ranging from 1% to 50% acceptance. Also for this study, customers with two refrigerators and/or freezers in use are taken into account for this market size.



DEMAND RESPONSE POTENTIAL (KW) KW REDUCTION MARKET SIZE 1%

ACCEPTANCE 5%

ACCEPTANCE 10%

ACCEPTANCE /UNIT 20%

ACCEPTANCE 50%

ACCEPTANCE

Refrigerator

SCE 5,153,497 46,381 9,276 92,763 185,526 463,815 0.18

CA 15,703,848 28,267 141,335 282,669 565,339 1,413,346

Freezer

SCE 649,601 1,039 5,197 10,394 20,787 51,968 0.16

CA 2,395,502 3,833 19,164 38,328 76,656 191,640

Water Heater

SCE 216,534 606 3,031 6,063 12,126 30,315 0.28

CA 931,584 2,608 13,042 26,084 52,169 130,422



STRATEGY 3 – APPLIANCE DECREASED POWER SETTINGS

STRATEGY DESCRIPTION Decreased power settings of appliances can be incorporated into ovens/ranges, dishwashers, clothes dryers, microwaves, refrigerators, and freezers. This strategy disables heating elements in ovens/ranges, dishwashers, and clothes dryers. For microwaves, the DR signal forces the microwave to decrease power settings. For refrigerators and freezers the compressor cycle increases.

TECHNICAL DEMAND REDUCTION With the strategy of forcing appliances into a lower setting and disabling heating elements, it is assumed the appliances demand reduction is half of its demand draw, see Table 15.

TABLE 15. DEMAND REDUCTION FOR RESIDENTIAL APPLIANCES

APPLIANCE DEMAND REDUCTION (KW)

Oven/Range 0.055

Dishwasher 0.025

Clothes Dryer 0.1

Microwave 0.009

Refrigerator 0.09

Freezer 0.08

MARKET ACCEPTANCE The foreseen market barrier for acceptance of this DR strategy is customer preference for appliance usage on demand. When a customer uses an appliance its full function is usually needed at that exact moment. Decreasing appliance performance through lower power settings can have some market resistance. There are times when an appliance’s full function is not needed. In those cases decreased power settings is a viable option. Added hardware will need to be installed in order for customers to comfortably incorporate DR into their appliance usage. This added hardware is an interface for the customer to understand their appliance usage and the monetary impact on appliance usage. The impacts along with their understanding of their appliance usage could give customers information as to their actual need of full functional settings for their appliance at that time. This DR strategy will have difficult acceptance without the proper education on the utilities need and the customer’s benefits. This strategy needs to be a performance-based incentive as customers are likely to override a DR event often. Overall, the acceptance of this strategy should be good for most appliances, as the appliances are still functional. This strategy may have a long adoption rate due to the manufacturer’s need to develop and incorporate an interface and controls for a Smart Appliance. Since there is no market acceptance data for a DR program for residential appliances, estimations are made ranging from 1% to 50% acceptance.




DEMAND RESPONSE POTENTIAL Using Equation 1 the total DR potential is calculated and listed in Table 16 for SCE service territory and statewide


DEMAND RESPONSE POTENTIAL (KW) KW REDUCTION /UNIT

MARKET SIZE 1% ACCEPTANCE

5% ACCEPTANCE

10% ACCEPTANCE

20% ACCEPTANCE

50% ACCEPTANCE

Ovens/Ranges

SCE 1,169,281 643 3,216 6,431 12,862 32,155 0.055

CA 5,589,505 3,074 15,371 30,742 61,485 153,711

Dishwashers

SCE 2,598,402 650 3,248 6,496 12,992 32,480 0.025

CA 8,118,091 2,030 10,148 20,295 40,590 101,476

Clothes Dryers

SCE 779,521 780 3,898 7,795 15,590 38,976 0.1

CA 3,859,420 3,859 19,297 38,594 77,188 192,971

Microwaves

SCE 4,157,443 374 1,871 3,742 7,483 18,708 0.009

CA 12,642,929 1,138 5,689 11,379 22,757 56,893

Refrigerators

SCE 5,153,497 4,638 23,191 46,381 92,763 231,907 0.09

CA 15,703,848 14,133 70,667 141,335 282,669 706,673 Freezers

SCE 649,601 520 2,598 5,197 10,394 25,984 0.08

CA 2,395,502 1,916 9,582 19,164 38,328 95,820

RESULTS Three DR strategies were assessed in this report and listed below are the varying results dependent on a 1% to 50% acceptance for SCE service territory and statewide:

Strategy 1: Appliance delayed start/off SCE: Clothes Washers 0.5 to 25 MW



SCE: Ovens/Ranges 1.3 to 64 MW


CA: Clothes Washers 1.5 to 74 MW





Strategy 2: Appliance temperature reset/pre-cooling SCE: Refrigerators 9.3 to 464 MW


SCE: Water Heaters 0.6 to 30 MW

CA: Refrigerators 28 to 1,413 MW


CA: Water Heaters 2.6 to 130 M


Strategy 3: Appliance decreased power settings SCE: Ovens/Ranges 0.6 to 32 MW




SCE: Refrigerators 4.6 to 232 MW






CA: Refrigerators 14 to 707 MW


Since there is no data on acceptance of a DR program for residential appliances, estimations were made ranging from 1% to 50% acceptance. Strategy 1 is expected to have a low acceptance since appliance use is typically needed at the moment of demand. Strategy 2 is the best strategy to employ. This strategy allows the customer to choose/experiment with different temperature settings in preparation for a DR event. Increasing the chance of market acceptance since the customer is in control of their participation. This strategy is also favorable as it falls in line with future plans to pay DR incentives on performance. Strategy 3 is expected to have a good acceptance for most appliances, as the appliances are still functional, but with lower power settings may increase inconvenience to customers. All strategies are viable to be incorporated into Title 20, but controls will have to be incorporated to allow the utility to communicate to the appliances through its infrastructure.

RECOMMENDATIONS Strategies identified in this report provide a large opportunity for DR programs in terms of net demand reduction in SCE service territory. All strategies are high candidates to be incorporated into Title 20 by incorporating controls with the ability to communicate with a utilities’ infrastructure.

Recommended next steps are to perform a more recent study on appliance load profiles and to survey customers on their likeliness to participate in each of the strategies for incentive- based DR programs for their appliances. Also field testing of appliance temperature resets and low power setting-enabled appliances should be initiated to understand their impact. This includes working with different manufacturers to promote and develop ZigBee communications to the appliances controls. A field evaluation will help to better understand actual demand reduction and collect some market feedback on strategies being employed.



APPENDIX A

.

FIGURE 2. REFRIGERATOR LOAD PROFILE

FIGURE 3. FREEZER LOAD PROFILE



FIGURE 4. CLOTHES WASHER LOAD PROFILE

FIGURE 5. CLOTHES DRYER LOAD PROFILE



FIGURE 6. WATER HEATER LOAD PROFILE

FIGURE 7. DISHWASHER LOAD PROFILE



FIGURE 8. OVEN/RANGE LOAD PROFILE

FIGURE 9. MICROWAVE LOAD PROFILE




REFERENCES

1 California Statewide Residential Appliance Saturation Study. June 2004. CEC-400-04-009, p. 4 2 1996 Residential Appliance End-Use Study. January 1998. Southern California Edison, prepared by

Quantum Consulting, P776.320 3 EPRI DR Appliance presentation by whirlpool 4 Southern California Edison Customer Database 5 U.S. Census Bureau, California QuickFacts, http://quickfacts.census.gov/qfd/states/06000.html,

accessed on November 6, 2009 6 California Statewide Residential Appliance Saturation Study. June 2004. CEC-400-04-009, pg. 4-5 7 Food and Drug Administration

http://quickfacts.census.gov/qfd/states/06000.html


INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR RESIDENTIAL POOL PUMPS Phase1: Demand Response Potential

DR 09.05.10 Report

Prepared by:


November 30, 2009


Introduction.....................................

Market Size......................................

Barriers...........................................


Results............................................


References ......................................

1

3

5

6

6

10

10

11

Integration of DR into Title 20 for Residential Pool Pumps DR 09.05.10


Acknowledgements


Disclaimer


Integration of DR into Title 20 for Residential Pool Pumps DR 09.05.10



kW Kilowatt


Integration of Demand Response into Title 20 for Residential Pool Pumps DR 09.05.10

EXECUTIVE SUMMARY This project seeks to validate and establish the demand response (DR) potential for residential pool pumps and to assess the potential for DR capable pool pumps to be included in California’s Appliance Efficiency Regulations (Title 20). This project may follow up with demonstrations of the DR strategies identified, and could ultimately lead to the development of code language, Phases 2 and 3, respectively.

Pool pumps main function is to circulate and filter swimming pool water. This important function is essential in residential pool maintenance by keeping the pool relatively free of dirt, debris, and bacteria. Pool pumps are almost always the largest single electrical end-use of residential customers with pools. Annual average energy used by pool pumps in a California home is estimated to be 2,580 - 3,096 kWh with an average demand of 1.354 kW. Market size was estimated using California Statewide Residential Appliance Saturation Study. Southern California Edison (SCE) service territory has over 4.3 million residential customers and it is estimated that 62% of this population are single family residences. Of the single family residences, 14.9% are estimated to own a pool. Using a 62% value for single family residences and a 14.9% pool ownership rate, there are an estimated 400,000 single family residential customers who own pools within SCE’s service territory.

For this study three demand response (DR) strategies were assessed

Strategy 1: Pool pump shutoff/cycling

Strategy 2: Low speed control settings for two-speed pool pumps

Strategy 3: Low speed control settings for variable-speed pool pumps

From the pool pump DR study surveys it was found that 76% of customers surveyed are interested in an incentive-based pool pump DR program. It was also estimated that Strategy 1’s DR potential was about 193.5 MW, Strategy 2’s DR potential was about 42 MW, and Strategy 3’s DR potential was about 18 MW. The current market is 99% single-speed pool pumps, but it is anticipated that due to code requirements, SCE’s incentives could push the market to be 25% two-speed and 10% variable-speed pool pumps. Strategy 1 is the quickest and the easiest for DR acceptance, due to its structure mimicking a current DR strategy of air conditioning cycling. It also has the largest DR potential due to every type of pool pump’s ability to participate. Strategy 2 has the next largest DR potential, but it is much lower than Strategy 1 due to the assumed future market size of two-speed pool pumps. The acceptance of this strategy should be higher as there is a better assurance of water quality. Customers would be better assured of water quality, as a pool normally on during peak hours, still circulates water, just at a lower speed. Strategy 3 is the best strategy/technology to employ. This strategy allows customers to choose/experiment with different speed settings and be willing to decrease their speed settings during a DR event. Thus, increasing the chance of market acceptance since the customer is in control of their participation. This strategy is also favorable with the utility because it falls in line with SCE’s SmartConnect™ infrastructure and future plans to pay DR incentives on performance. The biggest hurdle for this strategy is the lack of market size due to incremental cost and education of the technology.

Only two strategies are viable to be incorporated into Title 20 as single-speed pool pumps are no longer commercially available in California. In order to accommodate the other two strategies, controls have to be incorporated into both two-speed and variable-speed pumps to allow the utility to communicate to the pool pump through its SmartConnect infrastructure. Current single-speed pool pump owners will need a retrofit controls system



with the ability to communicate with the utilities’ infrastructure and ability/smarts to ensure water quality with the proper turnover.

Strategies identified in this report provide a large opportunity for DR programs in terms of net demand reduction in SCE service territory. Strategies 2 and 3 are high candidates to incorporate into Title 20 by incorporating controls with the ability to communicate with SCE’s SmartConnect infrastructure and controls to ensure water quality. Strategy 1 is the quickest way of implementing a DR program for pool pumps due to the high market share of single-speed pool pumps. There is no way of incorporating the controls into Strategy 1 through Title 20 due to the new requirement of two-speed pool pumps.

Recommended next steps are to perform Phase 2 field testing of Strategies 2 and 3 to continue to explore and test the various technology aspects of pool pump controls and communications. This includes working with pool pump manufacturers to promote and develop ZigBee® communications to pool pump controls to understand actual demand reduction and to get some market feedback on strategies being employed.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for residential pool pumps. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to residential pool pumps.

This project aligns well with the objective of Southern California Edison’s (SCE) SmartConnect™ by fostering and accelerating the availability of DR-ready appliances in the market place. Furthermore, this project supports the California Public Utilities Commission goal of zero net energy for residential new construction by 2020 and commercial new construction by 2030.

Phase 1 of this potential three-phase effort addresses the DR potential for pool pumps; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for pool pumps; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for pool pumps.

This report reviews the findings from Phase 1 and estimates the DR potential for pool pumps. This phase entails assessing the demand reduction associated with pool pumps, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with pool pumps.

TECHNOLOGY DESCRIPTION Pool pumps main function is to circulate and filter swimming pool water. This important function is essential in residential pools’ maintenance by keeping the pool relatively free of dirt, and debris. A typical pool pump consists of an electric motor, impeller, pump basket, and casing as shown in Figure 1. The electric motor spins the impeller. The impeller forces water from the intake port through the pump basket. As the water enters the pump basket large debris is removed. After the water exits the pump basket the water is pushed by the impeller out of the discharge port. The water from the inlet port originates from the various drains piped from the pool. The discharged water goes through the different pool systems, such as a filter, chemical treatment system, and sometimes a heater. From the different pool systems, the water is piped back to the pool. There are three types of pool pumps:

Single-speed: A pool pump with only one speed the motor can turn the impeller.

Two-speed: A pool pump with two speeds the motor can turn the impeller.

Variable-speed: A pool pump where the frequency of the power can be controlled to vary the speed the motor can turn the impeller.



FIGURE 1. POOL PUMP COMPONENT DIAGRAM

CURRENT ENERGY CODE REQUIREMENTS Title 20, Section 1605.3,1 requires that pool pump motors that are manufactured on or after January 1, 2008, with a capacity of 1 HP or more, shall have the capability of operating at two or more speeds with a low speed having a rotation rate that is no more than one-half of the motor’s maximum rotation rate. Title 20 further requires that pool pump motor controls shall have the capability of operating the pump at a minimum of two speeds, and that the default circulation speed shall be the lowest speed, with a high speed override capability being for a temporary period not to exceed one normal cycle. Motor efficiency for pool pumps manufactured on or after January 1, 2006 may not be split-phase or capacitor start – induction run type. Also, currently there is neither ENERGY STAR labeling nor a Consortium for Energy Efficiency standards for residential pool pumps

DEMAND PROFILE AND ENERGY CONSUMPTION Pool pumps are almost always the largest single electrical end-use of residential customers with pools. Annual energy usage data is estimated to be 2,580 to 3,096 kWh by using the California Statewide Residential Appliance Saturation Study.2 Demand and hours of operation are obtained from the 2008 Pool Pump DR Potential study. The average power draw is estimated to be 1.364 kW with an average horse power rating of 1.31 hp.3 Pool pumps in SCE service territory operate an average of 5.18 hours per day including 5.14 hours in coastal regions, 5.81 hours in desert regions, and 4.59 hours in inland valley regions.4 The percentage of pools “on”, varies by the time of day. Figure 2 shows 24-hour profiles of pool pump operation as well as a profile of pool pumps average kW demand.5 It is estimated that the highest percentage of pool pumps operating in the afternoon hours is 46.7% and occurs between 12 P.M. and 1 P.M.6 Figure 2 also shows that a large percentage of pool pumps are running during the peak period of 12 P.M. to 6 P.M. It is estimated that nearly 99% of pool pumps within California are single-speed pool pumps.



0%

10%

20%

30%

40%

50%

60%

70%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour of Day

Perc

ent o

f Pum

ps O

n

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

Ave

rage

kW

Percent On Average kW

FIGURE 2. HOURLY AVERAGE KW DEMAND AND OPERATING PROFILES

MARKET SIZE Market size was estimated using California Statewide Residential Appliance Saturation Study. SCE service territory has over 4.3 million residential customers7 and it is estimated that 62% of this population are single family residential.8 Of the single family residential customers, 14.9% are estimated to own a pool.9 Using a 62% single-family residential and 14.9% ownership rate, there are an estimated 400,067 single-family residential customers who own pools within SCE service territory.

Overall, California has over 13.3 million residential customers10 with an estimated 14% of single family homes having pools.11 Using SCE data of 62% single family residential and 14% pool ownership there are an estimated 1,237,326 residential customers who own pools in California.



MARKET BARRIERS The most significant barrier to incorporating DR capabilities into a pool pump is ensuring proper water quality through proper turnover. From the pool pump DR study it was found that 76%12 of customers surveyed are interested in an incentive-based pool pump DR program. The current market is over 99% single-speed pool pumps with very primitive controls, such as timers. The need for better controls is necessary along with penetration of better pool pump technology. Better controls will need the ability to know how much run- time is needed in a particular day and ability/smarts to turnover the pool even when a DR event occurs. This type of control paired with the newer types of pool pumps can further the growth and acceptance of a DR program for pool pumps. Another significant barrier to incorporating DR strategies into pool pumps is the perceived lack of control, skepticism about cost savings, which all fall under the level of trust in SCE. These barriers can be addressed by education and outreach to teach customers about the DR strategies and their benefits. Key education elements include risk, savings, override capability, program incentives and safety mechanisms to ensure pool safety.

DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, it is assumed SCE’s SmartConnect infrastructure is in place and the DR-ready pool pump is commercially available. The DR potential is defined in Equation 1.



STRATEGY 1 – POOL PUMP SHUTOFF/CYCLING

STRATEGY DESCRIPTION This strategy relies on a signal being sent to the pool pump to turn it off for a period of time. The period of time gives the utility the flexibility to package different tiered programming, mimicking SCE’s current AC cycling. This tiered package of incentives gives the customer the cycling amount from 25% - 100% cycling of a pool pump during on-peak time periods.

TECHNICAL DEMAND REDUCTION With this strategy forcing the pool pumps operational state to off, the maximum demand reduction of 1.364kW per unit can be expected.

MARKET ACCEPTANCE A foreseen barrier of acceptance for this DR strategy is ensuring proper water quality. With the pool pumps current 24-hour usage data, some pools can have a turnover issue if the controls don’t have the ability/smarts to turnover the pool even when a DR event occurs. Improper turnover can affect water quality. Currently, the majority of pool pump controls are just plain timers. Added hardware is needed in order for customers to safely incorporate DR into their system. This DR strategy also



has difficult acceptance without the proper education on pool maintenance and the ability for customers to decline a DR event. Overall, the acceptance of this strategy should be high as long as the proper controls technology and control is given to the market. This strategy is initially the quickest way for adoption due to the current market share of single-speed pool pumps. Even if market adoption were low the market size allows the strategy to have a high DR potential. In the DR potential calculation, the market size is decreased since it is estimated the maximum amount of pools “on” is 46.7% during peak periods. The new market size has decreased SCE’s market to 186,831 and California to 577,831. For this study 76%12 is used to represent the market acceptance of this DR strategy.



MARKET SIZE DR POTENTIAL (KW) KW

REDUCTION/UNIT SCE STATEWIDE MARKET ACCEPTANCE

SCE STATEWIDE 1.364 186,831 577,831 76% 193,677 599,003

STRATEGY 2 – LOW SPEED CONTROL SETTINGS FOR TWO-SPEED POOL PUMPS

STRATEGY DESCRIPTION This strategy only leverages customers with a two-speed pump. The strategy forces the pool pump to run in the lower speed for a period of time.

TECHNICAL DEMAND REDUCTION With this strategy, the pool pump is forced into the lower of the two speeds it offers. This offers a significant opportunity for demand and energy savings by taking advantage of pump affinity laws. The affinity law states the power demanded by a pump is proportional to the cube of the flow rate. In other words, if a pump’s flow rate is reduced by half, its power demand is reduced to one-eighth. Operating a pump equipped with a two-speed motor at half speed for twice as long therefore moves the same volume of water, but in theory uses only one-quarter the amount of energy (1/8 kW x 2 hrs = 1/4 kWh). Therefore, the expected kW reduction is 1.364 kW - (1.364kW x 1/8) = 1.1935 kW.

MARKET ACCEPTANCE A foreseen barrier for acceptance of this DR strategy is ensuring proper water quality. With the pool pumps current 24-hour usage data, some pools can have a turnover issue if the controls don’t have the ability/smarts to turnover the pool even when a DR event occurs. Improper turnover can affect water quality. This DR strategy also has difficult acceptance without the proper education on pool maintenance and the added ability for a customer to decline or not participate in a DR event. Also, with 99% of the market being single-speed pool pumps, the future market share of two-speed pool pumps is assumed to be 25%. The growth is due to the code requirement for all new pool pumps to be two-speed within California. By



assuming 25% of the pool pumps are two-speed, the market size for this strategy decreases SCE’s market to 100,017 and California to 309,332. Further more, the market is then decreased more since it is estimated the maximum amount of pools “on” was 46.7%. The new market size used for DR potential calculations has decreased SCE’s market to 46,708 and California to 144,458. Low-speed control settings for two-speed pool pumps are also an even more attractive DR strategy for customers. Customers are better assured of water quality, as a pool normally on during peak hours, is still circulating water, just at a lower speed. The strategy gives better water quality safety, but the size of the market is significantly smaller. It is beneficial to incorporate controls with the ability to communicate with SCE’s SmartConnect infrastructure and controls to ensure water quality into Title 20. For this study 76% is used to represent the market acceptance of this DR strategy.

DEMAND RESPONSE POTENTIAL Using Equation 1, the total DR potential is calculated and listed in Table 2 for SCE service territory and statewide.




SCE STATEWIDE 1.1935 46,708 144,458 76% 42,367 131,032

STRATEGY 3 – LOW SPEED CONTROL SETTINGS FOR VARIABLE-SPEED POOL PUMPS

STRATEGY DESCRIPTION This strategy only leverages customers with a variable-speed pool pump. This strategy forces the pool pump to run at a lower speed. A variable-speed pool pump gives the utility, along with the customer much more flexibility to decide their participation level. The flexibility allows the customer to choose/experiment with different speed settings. By allowing the customer to experiment and try different speed settings, the customer is in control of their participation. This strategy is also favorable with the utility because it falls in line with future plans to pay DR incentives on performance. For the purpose of this assessment a speed decrease of 40% is used.

TECHNICAL DEMAND REDUCTION This strategy of forcing the pool pump to lower speeds to 40% using a variable speed drive offers a significant opportunity for demand and energy savings by taking advantage of pump affinity laws. The affinity law states the power demanded by a pump is proportional to the cube of the flow rate. In other words, if a pump’s flow rate is reduced by 60%, its power demand is reduced to 1/15.625. Therefore the expected kW reduction is 1.364 kW - (1.364kW x 1/15.625) = 1.277 kW.



MARKET ACCEPTANCE The foreseen barrier for acceptance of this DR strategy is ensuring proper water quality. With the pool pumps’ current 24-hr usage data, some pools can have a turnover issue that affects water quality. Once again the controls technology needs the ability to make up lost flow when switching to a lower speed to ensure high water quality. This DR strategy also has difficult acceptance without the proper education on pool maintenance and the ability for a customer to decline a DR event. Also with 99% of the market being currently single-speed pool pumps, the market share of variable speed pool pumps is assumed to be 10%. The slower growth is due to the very high incremental cost between the current code requirements of two-speed pool pumps. The high incremental cost is currently a target of SCE’s Express Efficiency rebate program to help accelerate the adoption of this technology. By assuming that 10% of the pool pumps are variable-speed, the market size for this strategy will decrease SCE’s market to 40,007 and California to 123,733. Further more, the market then decreases more since it is estimated the maximum amount of pools “on” is 46.7%. The new market size used for DR potential calculation has decreased SCE’s market to 18,683 and California to 57,783. Low-speed control settings for variable-speed pool pumps are also an attractive DR strategy for customers. The strategy provides better water quality safety, but the size of the market is significantly smaller dragging the DR potential down. The acceptance within this market is also much higher compared to the other two strategies because customers who are forward-minded and understanding of new technology usually understand the goals and strategies used in a DR program. Also, pool pumps normally scheduled to run during peak times are still running during a DR event, just at a lower speed. This gives the customer more reassurance the DR strategy will not adversely affect water quality. Further, the variable speed technology better aligns with SCE’s SmartConnect infrastructure due to the larger range of control to a pool pump. That range of control can be leveraged in future plans for a performance-based incentive DR program, giving a large benefit that can be incorporated into Title 20. For this study 76% is used to represent the market acceptance of this DR strategy.

DEMAND RESPONSE POTENTIAL Using Equation 1, the total DR potential is calculated and listed in Table 3 for SCE service territory and statewide.




SCE STATEWIDE 1.277 18,132 56,080 76% 17,597 54,427



RESULTS Three demand response strategies were assessed:

Strategy 1: Pool pump shutoff/cycling

Strategy 2: Low speed control settings for two-speed pool pumps

Strategy 3: Low speed control settings for variable-speed pool pumps

From the pool pump DR study it was found that 76% of customers surveyed are interested in an incentive-based pool pump DR program. It was estimated that Strategy 1 DR potential was about 193.5 MW, Strategy 2 DR potential was about 42 MW, and Strategy 3 DR potential was about 18 MW. The current market is 99% single-speed pool pumps, but it is anticipated that due to code requirements and SCE’s incentives could push the market to be 25% two-speed and 10% variable speed pool pumps. Strategy 1 is the quickest and the easiest for acceptance, due to its structure mimicking a current DR strategy for AC cycling. It also has the largest DR potential due to every type of pool pump’s ability to participate. Strategy 2 has the next largest DR potential, but it is much lower than Strategy 1 due to the assumed future market size of two-speed pool pumps. The acceptance of this strategy should be higher as there is a better assurance of water quality. Customers are better assured of water quality, as a pool normally ON during peak hours is still circulating water, just at a lower speed. Strategy 3 is the best strategy/technology to employ. This strategy allows the customer to choose/experiment with different speed settings if they are willing to be turned down during a DR event. This strategy increases the chance of market acceptance since the customer is in control of their participation. This strategy can also be favorable with the utility future plans to pay DR incentives on performance. The biggest hurdle for this strategy is the lack of market size due to incremental cost and education of the technology. Only two strategies are viable to be incorporated into Title 20 as single-speed pool pumps are not commercially available. In order to accommodate the other two strategies, controls will have to be incorporated into both two-speed and variable-speed pumps to allow the utility to communicate to the pool pump through its infrastructure. Current single-speed pool pump owners will need a retrofit controls system with the ability to communicate with the utilities infrastructure and ability/smarts to ensure water quality with the proper turnover.

RECOMMENDATIONS Strategies identified in this report provide a large opportunity for DR programs in terms of net demand reduction in SCE service territory. Strategies 2 and 3 are high candidates to incorporate into Title 20 by incorporating controls with the ability to communicate with a utilities infrastructure and controls to ensure water quality. Strategy 1 is the quickest way of implementing a DR program for pool pumps due to the high market share of single-speed pool pumps. There is no way of incorporating the controls into Strategy 1 through Title 20 due to the new requirement of two-speed pool pumps.

A recommended next step is to perform a Phase 2 field test of Strategy 2 and 3 to continue to explore and test the various technology aspects of pool pump controls and communications. This includes working with pool pump manufacturers to promote and develop ZigBee® communications to pool pump controls to understand actual demand reduction and get some market feedback on strategies being employed.




REFERENCES

1 Appliance Efficiency Regulations. December 2006. CEC-400-2006-002-REV2, p. 119 2 California Statewide Residential Appliance Saturation Study. June 2004. 400-04-009, p. 4 3 Pool Pump Demand Response Potential. Southern California Edison. June 2008. DR 07.01, p. 1 4 Ibid., p. 19 5 Ibid., p. 30 6 Ibid., p. 37 7 Southern California Edison Customer Database, Southern California Edison, accessed October 2009 8 Pool Pump Demand Response Potential. Southern California Edison. June 2008. DR 07.01, p. 36 9 Ibid. 10 U.S. Census Bureau, California QuickFacts, http://quickfacts.census.gov/qfd/states/06000.html,

accessed on November 6, 2009 11 California Statewide Residential Appliance Saturation Study. June 2004. 400-04-009, p. 5 12 Pool Pump Research for Demand Response: Telephone Survey. Southern California Edison.

January 2008, p. 4



INTEGRATION OF DEMAND RESPONSE INTO TITLE 20 FOR HOME OFFICE EQUIPMENT Phase1: Demand Response Potential

DR 09.05.11 Report

Prepared by:


November 30, 2009


Introduction.....................................



Results............................................


References ......................................

1

2

7

8

11

12

13

Integration of DR into Title 20 for Home Office Equipment DR 09.05.11

Southern California Edison International November 2009 Design and Engineering Services

Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.11. DES project manager Neha Wadhera conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer



ABBREVIATIONS AND ACRONYMS CPU Central Processing unit

DR Demand Reduction

FB Frame Buffer

GB Giga Byte

GPU Graphic Processing Unit

HOE Home Office Equipment

ipm Images Per Minute

kWh Kilowatt Hour

LAN Local Area Network

MW Mega Watts

TEC Typical Energy Consumption

TWh TeraWatt Hour

W Watt

Southern California Edison International Page i Design and Engineering Services November 2009


EXECUTIVE SUMMARY This project reviews the current research for home office equipment (HOE) and determines its demand response (DR) potential. This study further quantifies the energy savings and demand reduction associated with several potential DR strategies. HOE accounts for 31% of California’s residential plug load energy use. Typical HOE includes the following:

Desktop or laptop computers

Monitors

Printers

Fax machines

Routers

Modems

Speakers

Scanners

Copiers

An in-depth review of individual home office component’s power demand in various operating modes (e.g., active (maximum power demand), low power and standby (minimum power demand)), was done. Strategies proposed in this report result in potential savings of 71 MW-178 MW in Southern California Edison (SCE) service territory, depending upon the acceptance rate of either 20% or 50%, when appliances are switched from active mode to standby mode. Similar calculations project potential savings of 220 MW at a 20% acceptance rate and 551 MW at a 50% acceptance rate statewide for DR strategies proposed in this report. This effort falls in line with SCE’s SmartConnect initiative and its vision to integrate DR into Title 20. Several strategies are proposed in this report encompassing major home office equipment:

Using existing Local Area Network (LAN) in a residence to switch a device from active to standby mode when a DR event is called. This strategy, if implemented on desktop computers and monitors, provides a demand reduction of approximately 163 MW.

Network control of power options menu available in computers

Tapping into LANs to switch routers and modems to standby mode during a DR event.

All strategies are viable and can be incorporated into Title 20, but controls should be integrated into HOE to allow two-way communications to make them DR addressable. However, DR savings projected in this report are highly dependent on time-of-use profiles of individual home office components. Any increase in hours of active mode operation of the equipment can lead to higher demand reduction potential. This current lack of information calls for a closer look into hours of operation for each device in various modes and corresponding average power draw for each device that constitutes a home office.

This exercise also highlights the lack of information and research performed on various home office equipments such as: printers, scanners, speakers, Fax machines, etc. The market for such devices is steadily growing and is expected to grow at a higher rate as new technology becomes more affordable and readily available to residential customers. These factors make this market segment an even better candidate for DR applications. Thus, further study/research in the form of a Phase 2 evaluation is recommended to evaluate customer response and feedback on the strategies proposed.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for home office equipment (HOE). It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to HOE.


1HOE has a 31% share of California’s residential plug load energy use. This translates into an annual energy consumption of about 579 to 749 kilowatt hours per unit (kWh/unit).2 Residential electric energy use is estimated to grow at a rate of 2.4% per year as new and more efficient technologies become available to customers.3 In the year 2030, energy consumption for personal computers alone is estimated to be 68 terawatts per hour (TWh).4 Overall, energy consumption of all HOE is touted to be much higher.

Phase 1 of this potential three phase effort addresses the DR potential for HOE; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for HOE; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for HOE.

This report reviews the findings from Phase 1 and estimates the DR potential for HOE. This phase entails assessing the demand reduction associated with HOE, the population statewide and within SCE service territory, and the market/customer acceptability of DR strategies associated with HOE.

TECHNOLOGY DESCRIPTION HOE is now used by everyone in the household on a daily basis. On average about 23% of the households in California have home offices5 that contribute significantly to the overall average electric consumption.

Typical home office components include:

• Desktop or laptop computers

• Monitors

• Printers

• Fax machines

• Routers

• Modems

• Speakers

• Scanners

• Copiers




CURRENT ENERGY CODE REQUIREMENTS HOE components such as laptops, scanners, copiers etc. are not regulated; however the external power supplies (EPS) to these devices are regulated by Title 20. EPS is defined in Title 20 as:

“… an external power supply circuit that is used to convert household electric current into DC current or lower-voltage AC current to operate a consumer product…”6

Title 20 and federal efficiency standards and ENERGY STAR energy efficiency guidelines for external power supplies are listed in Table 1 and Table 2. These energy code requirements and guidelines are valid for external power supplies used with laptop computers, mobile phones, printers, scanners, copiers, print servers, personal digital assistants, digital cameras, etc.

Table 1 and Table 2 show calculated energy efficiency requirements for external power supplies for both active and no load mode according to Title 20.7

TABLE 1. ENERGY CODE REQUIREMENTS FOR EXTERNAL POWER SUPPLIES – ACTIVE MODE

NAME PLATE

OUTPUT (WATTS)

2007 TITLE20

CODE MINIMUM

EFFICIENCY

REQUIREMENT IN

ACTIVE MODE

2008 TITLE 20

CODE MINIMUM

EFFICIENCY

REQUIREMENT IN

ACTIVE MODE

2008 FEDERAL

CODE MINIMUM

EFFICIENCY

REQUIREMENT IN

ACTIVE MODE

ENERGY

STAR

GUIDELINES, STANDARD

MODELS8

ENERGY

STAR

GUIDELINES, LOW

VOLTAGE

MODELS9

0.5 0.245 0.250 0.250 0.380 0.315

25 0.779 0.789 0.789 0.823 0.802

55 0.840 0.850 0.850 ≥0.870 ≥0.860

TABLE 2. ENERGY CODE REQUIREMENTS FOR EXTERNAL POWER SUPPLIES – NO LOAD MODE

NAME PLATE

OUTPUT (WATTS)

2007 TITLE 20 MAXIMUM ENERGY

CONSUMPTION IN NO- LOAD MODE

(WATTS)

2008 TITLE 20 MAXIMUM ENERGY


(WATTS)

2008 FEDERAL MAXIMUM ENERGY


(WATTS)

0 to <10 0.5 -- --

≥ 10 to ≤ 250 0.75 -- --

≥ 250 -- -- 0.5

Any Output -- 0.5 --


A laptop typically consumes 23 watts per unit and its external power supply is required to have an efficiency of at least 0.823 according to the ENERGY STAR efficiency guidelines. Similarly, an external power supply of a desktop or any device that has a rated output greater than 51 watts is required to have at least an efficiency of 0.860.

There are no current state and federal code requirements for desktop/laptop computers, small scale servers, printers, etc. However, ENERGY STAR energy efficiency guidelines are available and are listed in 10 11 12Table 3 , Table 4 , and Table 5 as annual typical energy consumption (TEC).

TABLE 3. ENERGY STAR EFFICIENCY GUIDELINES FOR DESKTOP/LAPTOP COMPUTERS

LAPTOP COMPUTERS (KWH/YR)

DESKTOPS AND INTEGRATED

COMPUTERS (KWH/YR)

Annual Typical Category A:≤ 148.0 Category A: ≤ 40.0 Energy Category B:≤ 175.0 Category B: ≤ 53.0 Consumption Category C:≤ 209.0 Category C: ≤ 88.5 (TEC)

Category D:≤ 234.0

Capability Adjustments

Memory 1 (per GB over Base) 0.4 (per GB over 4GB) Base Memory: Category A,B,C: 2GB Category D: 4GB

Premium graphics Cat A, B: 35 (FB width ≤ Cat B: 3 (FB Width (for discrete GPUs 128 bit) >64-bit) with specified 50 (FB width < frame buffer 128 bit) widths)

Cat C, D: 50 (FB width > 128 bit)

Additional Internal 25 3 Storage



ENERGY STAR definition for desktop/laptop computer categories is:

Category A: All desktop computers that do not meet the definition of category B, category C or Category D below are considered under Category A of ENERGY STAR labeling.

Category B: Category B desktops must have:

Core equal to 2 physical cores

System memory greater than or equal to 2GB

Category C: category C desktops must have:

Greater than 2 physical cores

In addition to the requirement above, a Category C desktop must have at least one of the two features listed below:

≤ to 2GB of system memory and/ or;

A discrete Graphic Processing Unit (GPU)

Category D: Category D desktops must have:

≤l to 4 physical cores

In addition to the requirement above a, Category D desktops must have at least one of the two features listed below:

≤ 4 GB of system memory and/ or;

A discrete GPU with a frame buffer with < 128-bit.

TABLE 4. ENERGY STAR EFFICIENCY GUIDELINES FOR MONOCHROME PRINTERS, COPIERS, FAX MACHINES, ETC.

MONOCHROME PRODUCT SPEED IMAGES

PER MINUTE (IPM) MAXIMUM TYPICAL ENERGY CONSUMPTION

(TEC) (KWH/WEEK)

≤15 1.0 kWh

15< s ≤40 (0.10 kWh/ipm) s - 0.5 kWh

40< s ≤82 (0.35 kWh/ipm) s -10.3 kWh

>82 (0.70 kWh/ipm) s -39.0 kWh

s = images per minute

TABLE 5. ENERGY STAR EFFICIENCY GUIDELINES FOR COLOR PRINTERS, COPIERS, FAX MACHINES, ETC.

COLOR PRODUCT SPEED (IPM) MAXIMUM TEC (KWH/WEEK)

≤32 (0.10 kWh/ipm) s + 2.8 kWh

32 < s ≤ 58 (0.35 kWh/ipm) s - 5.2 kWh

>58 (0.70 kWh/ipm) s - 26.0 kWh

s = images per minute



DEMAND PROFILE AND ENERGY CONSUMPTION Energy usage for all consumer electronics in California represents 15% to 17% of total residential electricity usage in California.13 A typical California household consumes 1,000 to 1,200 kWh/yr in its plug loads.14 This electricity consumption does not include installed white goods (washers, dryers, dishwashers, refrigerators, etc.), that last an average of 10 years or more. Overall, for all end uses an average “new construction” house uses approximately 7,035 kWh/yr.15

Desktop computers have the highest energy demand with 72 watts in active mode and 3.2 watts in standby mode. In comparison, laptops have a power demand of 23 watts in active mode and 1.5 watts in standby mode. Routers have the lowest active mode demand of 6.2 watts and 1.7 standby watts.

The average power consumption for all HOE components in active, low/idle, and standby modes is listed in 16,17 Table 6 below.

TABLE 6. POWER DRAW BY MODE FOR HOME OFFICE EQUIPMENT

ACTIVE

MODE

POWER

DRAW

(WATTS)

LOW

POWER/IDLE

MODE POWER

DRAW

(WATTS)

STANDBY

MODE POWER

DRAW

(WATTS)

EQUIPMENT

Desktops 72 10.6 3.2

Laptops 23 2.55 1.5

Monitors 44 1.52 1.2

Inkjet Printers 8.9 3.2 1.7

Laser Printers 39.0 9.6 1.3

Fax machines 28.4 5.3 2.2

Routers 6.2 -- 1.7

Modems (cable) 6.4 -- 4.5

Speakers 7.2 -- 2.3

Copiers 18.4 -- 1.2

Scanners 12.2 -- 5.7

It is important to note that the power draw for desktops, laptops, and monitors shown in Table 6 are an average of power consumption listed in two different studies conducted for residential appliance power consumption.



MARKET SIZE In 2006, an estimated 2.1 billion pieces of consumer electronic equipment were installed in the United States, and used 147 TWh of electricity (excluding digital TVs).18 Twenty-three percent of the total households in California, approximately 3 million homes, own a home office. SCE service territory has over 4.3 million customers19 20 of which 16% own a home office, which is close to 0.7 million.

There are approximately 9 million desktop computers and 3.6 million laptop computers in households statewide.21 The number of desktop and laptop computers in SCE service territory is proportional to the ratio of number of households in SCE service territory (approximately 4.3 million22 23), and the number of households statewide (approximately 13.39 million ). The ratio is equal to 0.32. This ratio, when applied to the number of desktop and laptop computers statewide, results in a total number of desktop and laptop computers in SCE service territory. As a result there are approximately 3 million desktops and more than 1 million laptops in SCE service territory. These figures are based on the assumption that each household has only one computer.

Note: The HOE referred to above does not include saturation levels for computers. Therefore, the number of computers statewide and within SCE service territory is taken into account in demand calculations for accuracy.

MARKET BARRIERS No overarching barriers, (e.g., health or food codes), were identified for HOE.

DEMAND RESPONSE STRATEGIES AND POTENTIAL For the purpose of this evaluation, the DR potential is defined in Equation 1.



STRATEGY 1 – TURN ON POWER OPTIONS FOR MONITORS, DESKTOPS, AND LAPTOP COMPUTERS

STRATEGY DESCRIPTION Every computer has a power options menu available on its control panel. These power options are usually not used but can be during a DR event. These options can be implemented via Local Area Network (LAN) protocol already present through an internet service provider. The LAN can be used to “force ON” these settings during a DR event. Typical DR power setting options include:

1. Turning off the monitor when it is idle for 20 minutes.

2. Turning off the hard drive after it has been idle for 20 minutes.



3. Modifying display settings to save power, for example, change the bit size, color resolution, etc. which requires fewer resources from the computer while it is in idle mode.

TECHNICAL DEMAND REDUCTION A typical desktop computer draws 72 watts, laptops draw 23 watts, and monitors draw 44 watts in active mode. The total maximum potential for demand reduction switching from active mode to standby mode for desktops and monitors is 111 watts per unit and 21.5 watts per unit for laptops.

MARKET ACCEPTANCE Foreseen barriers for acceptance of this DR strategy include consumer lack of awareness of available energy management systems and consumer concern that performance may be negatively impacted by energy management systems. Various acceptance scenarios are shown in Table 7.

DEMAND RESPONSE POTENTIAL Demand response potential:


TABLE 7. STRATEGY 1 – DR POTENTIAL AT VARIOUS ACCEPTANCE LEVELS FOR DESKTOPS AND MONITORS

DEMAND RESPONSE POTENTIAL (KW) KW REDUCTION/UNIT

1%

ACCEPTANCE 5%

ACCEPTANCE 10%

ACCEPTANCE 20%

ACCEPTANCE 50%

ACCEPTANCE MARKET SIZE

2,920,680 SCE 3,259 16,297 32,595 65,190 162,974 0.111

9,000,000 CA 10,044 50,220 100,440 200,880 502,200

TABLE 8. STRATEGY 1 – DR POTENTIAL AT VARIOUS ACCEPTANCE LEVELS FOR LAPTOPS


REDUCTION/UNIT

1%

ACCEPTANCE 5%

ACCEPTANCE 10%

ACCEPTANCE 20%

ACCEPTANCE 50%


SCE 1,168,272 251 2,256 2,512 5,024 12,559 0.021

CA 3,600,000 774 3,870 7,740 15,480 38,700

The above calculations show a potential of 176 MW demand reduction for desktop and laptop computers in SCE service territory at 50% acceptance rate. Overall, statewide, with 9 million customers, DR potential for computers is 541 MW.



STRATEGY 2 – NETWORK CONTROL OF POWER OPTIONS FOR MONITORS, DESKTOPS, AND LAPTOP COMPUTERS

STRATEGY DESCRIPTION Software tools can be used to control/adjust power remotely in conjunction with hardware that may be required and is compatible with PCs. These tools automatically adjust the power, brightness level of the screen, and central processing unit frequency according to a user’s needs. For example, if a user is operating multiple programs at the same time, this tool automatically adjusts the brightness level of the screen. Similarly, when fewer demands are placed on the computer, screen brightness is reduced accordingly.

TECHNICAL DEMAND REDUCTION A typical desktop computer draws 72 watts, laptops draw 23 watts, and monitors draw 44 watts in active mode. The total maximum potential for demand reduction switching from active mode to standby mode for desktops and monitors per unit is 111 watts and 21.5 watts per unit for laptops.

MARKET ACCEPTANCE Foreseen barriers of acceptance for this DR strategy include a lack of awareness among consumers about the availability of DR devices and consumer concerns regarding breech of privacy. Thus an acceptance factor of 20% is assumed for this strategy.

DEMAND RESPONSE POTENTIAL Demand response potential:


At 20% adoption rate the savings are close to 70 MW in SCE service territory and 216 MW statewide, as depicted in Table 7 and Table 8.

STRATEGY 3 – FORCE ROUTERS, MODEMS, AND HUBS INTO STANDBY MODE UNTIL DEVICES ARE NEEDED

STRATEGY DESCRIPTION Routers and modems spend 95% of their time in active mode even when they are not needed. These devices can be switched to standby mode and can be brought to active mode only when needed. This can be done wirelessly using LAN protocol. This strategy may provide the highest savings during weekdays when users are usually away from home compared to the savings on weekends when users may spend more time using these devices.

TECHNICAL DEMAND REDUCTION Demand reduction for routers, by forcing them into standby mode, averages 4.5 watts. For modems, demand reduction is approximately 2 watts per unit.



MARKET ACCEPTANCE Customers may be unwilling to implement this strategy as they may be skeptical due to security issues. For example, they may be fearful that someone having access to their computer could gain access to their stored financial or other personal information. An acceptance rate of 20% is assumed for this strategy.

DEMAND RESPONSE POTENTIAL Demand savings potential for this strategy is calculated using Equation 1 listed in the beginning of this section. Savings calculations for routers and modems are done separately as shown in Table 9 and Table 10.

TABLE 9. STRATEGY 3 – DR POTENTIAL FOR ROUTERS


REDUCTIO

N/UNIT

1%

ACCEPTANCE 5%

ACCEPTANCE 10%

ACCEPTANCE 20%

ACCEPTANCE 50%


SCE 695,453 31 156 313 626 1,565 0.0045

CA 3,080,592 139 693 1,386 2,773 6,931

TABLE 10. STRATEGY 3 – DR POTENTIAL FOR MODEMS


REDUCTIO

N/UNIT 1%

ACCEPTANCE 5%

ACCEPTANCE 10%

ACCEPTANCE 20%

ACCEPTANCE 50%


SCE 695,453 14 70 139 278 695 0.002

CA 3,080,592 62 308 616 1,232 3,081

Calculations for routers and modems show a potential savings of approximately 1 MW in SCE service territory. Statewide for more than 3 million customers, DR potential of routers and modems is 4 MW at 20% acceptance rate.

RESULTS Strategies discussed in this report provide a vast opportunity for DR programs in terms of net demand reduction in SCE service territory. Strategies 1 and 2 are similar but may have different acceptance rates due to different implementation methodology, but both provide a possibility for demand reduction, regardless.

Strategies 1 and 2 have the potential of saving 70 - 176 MW in SCE service territory. Strategy 3 can reduce the demand by 1 MW. This strategy can be evaluated in conjunction with strategies 1 and 2 since the equipment setup is already present in a typical home office setting. Strategy 1 is expected to have highest acceptance rate due to its simplistic approach.

Overall, DR potential for HOE calculated for SCE service territory and statewide, is summarized in Table 11 with corresponding market sizes and estimated acceptance rates.



TABLE 11. POTENTIAL DR SAVINGS FOR HOME OFFICE EQUIPMENT

MARKET SIZE

OVERALL DR POTENTIAL

(MW)

OVERALL

WATT

REDUCTION/ UNIT

ESTIMATED

MARKET

ACCEPTANCE

SCE

TERRITORY SCE

TERRITORY STATEWIDE STATEWIDE 0.111 (Desktops and Monitors) 2,920,680 9,000,000

50%

163 502

Strategy 1

0.0215 (Laptops) 50% 1,168,272 3,600,000 13 39

0.111 (Desktops and Monitors) 2,920,680 9,000,000

20%

65 201

Strategy 2

0.0215 (Laptops) 1,168,272 3,600,000 20% 5 15

Strategy 3 0.0065 (routers and

20%-50% modems) 695,453 3,080,592 1-2.3 4-10

RECOMMENDATIONS All strategies discussed in this report are viable and may be implemented, but controls shall be incorporated into HOE to allow two way communications and make them DR addressable. Strategy 1 and 2 are targeted towards desktop and laptop computers and strategy 3 targets routers and modems. Strategy 1 may have the highest acceptance rate among all strategies proposed and has a potential of 163 MW savings in SCE service territory. Overall, HOE strategies have a potential of 71-178 MW for SCE service territory and 220-551 MW statewide depending upon the acceptance rate of 20% or 50%. These strategies also fall in line with SCE’s SmartConnect initiative and future vision to integrate DR into Title 20.

Currently, home offices have a 31%Error! Bookmark not defined. share of residential energy use and are continuously increasing at a rate of 2.4%Error! Bookmark not defined. per year. By year 2030, computers alone will be responsible for 68Error! Bookmark not defined. TWh of energy use in the United States.

However, there are not enough studies done for all home office equipment. For years, PCs and monitors have been the focus of research performed on home offices; whereas devices such as printers, copiers, speakers, scanners, etc., have had very limited data to draw any viable conclusions regarding their power usage. It is recommended to:

Perform field tests to determine time spent by these devices in various operational modes, such as active, low/idle, and standby modes, and power usage in corresponding modes. Findings of such studies will have an impact on DR strategies and demand drop calculations discussed in this report, for example, if a device spends most of its time on standby mode,



DR potential for such devices may diminish as this report targeted for active mode demand response strategies only.

Address the following issue: the market share of the above listed devices is usually covered under miscellaneous plug loads. This is not a true representation of the number of devices installed in the United States or in SCE service territory.

Perform evaluations targeted for devices such as printers, scanners, fax machines, copiers, speakers, etc. These devices have been ignored due to their small contribution in residential electric usage, however, market and demand for such devices is steadily growing and is expected to grow at a faster rate as the technology becomes more affordable and more readily available for residential use.

Survey customers on their likeliness to participate in DR programs targeting HOE.

It is highly recommended that a Phase 2 evaluation be performed to further explore the points listed above and to have a better understanding of customer response and feedback on proposed strategies.




REFERENCES

1 Figure-1, Energy Use of Household Electronics: Taming the Wild Growth, PIER Technical Brief, September 2008, p. 1

www.energy.ca.gov/research 2 California Statewide Residential Appliance Saturation Study, Volume 2. June 2004, p. 9

http://websafe.kemainc.com/RASSWEB/uploads/Volume%202,%20sections%201%20and%202%20plus%20banners.pdf

3 U.S. Building Sector Energy Efficiency Potential, LBNL, Sep 2008, p. 1

http://enduse.lbl.gov/info/LBNL-1096E.pdf 4 Ibid, p. 2 5 2004 Residential Appliance Saturation Study ES, p. 34

http://websafe.kemainc.com/RASSWEB/uploads/RASS-ExecSummary-FINAL.pdf 6 Title 20, p. 60 7 Ibid, Table U-1, pg-134, Table U-2, pg-166, Table U-3, p. 167 8 ENERGY STAR website “program requirements” for external power supplies

http://www.energystar.gov/ia/partners/product_specs/program_reqs/eps_prog_req.pdf 9 Ibid 10 ENERGY STAR website “program requirements” for computers

http://www.energystar.gov/index.cfm?fuseaction=products_for_partners.showComputers 11 ENERGY STAR website “program requirements” for printers, scanners, FAX machines etc.

http://www.energystar.gov/index.cfm?fuseaction=products_for_partners.showPrintersScanners 12 Ibid 13 Ibid 1, pg-1 14 Ibid 15 Ibid 2, pg-10 16 ECEEE 2007 Summer Study, Kurt Roth and Kurtis McKenney TIAX LLC, pg-1362

http://www.eceee.org/conference_proceedings/eceee/2007/Panel_6/6.360/ 17 Final Field Research Report, Ecos Consulting, Oct 2006, pg-62

http://www.efficientproducts.org/documents/Plug_Loads_CA_Field_Research_Report_Ecos_2006.pdf

18 Ibid 17, pg 1363 19 Internal Communication, E-mail, Oct 2009, Portfolio Analysis, Measurement & Evaluation 20 Ibid 6, pg-4 21 Energy Information Administration website

http://www.eia.doe.gov/emeu/recs/recs2005/hc2005_tables/hc11homeelectronics/pdf/tablehc15.11.pdf

http://www.energy.ca.gov/research




http://www.energystar.gov/ia/partners/product_specs/program_reqs/eps_prog_req.pdf

http://www.energystar.gov/index.cfm?fuseaction=products_for_partners.showComputers

http://www.energystar.gov/index.cfm?fuseaction=products_for_partners.showPrintersScanners







22 Internal Communication, E-mail, Oct 2009, Portfolio Analysis, Measurement & Evaluation 23 U.S. Census Bureau, Population Division


INTEGRATION OF DR INTO TITLE 20 FOR HOME ENTERTAINMENT EQUIPMENT Phase1: Demand Response Potential

DR 09.05.12 Report

Prepared by:


November 30, 2009


Introduction.....................................



Results............................................


References ......................................

1

2

6

8

10

11

13

Integration of DR into Title 20 for Home Entertainment Equipment DR 09.15.12

Southern California Edison Design and Engineering Services November 2009

Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.12. DES project manager Neha Wadhera conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES, and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer



ABBREVIATIONS AND ACRONYMS CEE Consortium for Energy Efficiency

DR Demand Response

DVD Digital Versatile Disc

HEE Home Entertainment Equipment

HTIB Home Theatre in a Box

LCD Liquid Crystal Display

MW Mega Watt

STB Set Top Box

TWh TeraWatt Hour

VCR Videocassette Recorder

ZNE Zero Net Energy



EXECUTIVE SUMMARY This study seeks to determine and validate the demand response (DR) potential of Home Entertainment Equipment (HEE), evaluate the potential for incorporating HEE DR regulations into the California Appliance Efficiency Regulations (Title 20), and develop DR capabilities and strategies for home entertainment equipment.

Phase 1 efforts focus on identifying and establishing DR potential for HEE, by assessing and establishing its DR, identifying the HEE population within Southern California Edison (SCE) service territory, and determining the market/customer acceptance of DR strategies for HEE. Televisions (TVs) and Set Top Boxes (STB) contribute more than 8% of the residential energy use and demand for TV’s and it is growing at a rate of 2% per year. By year 2030, energy consumption by TV’s alone is estimated to cross 267 terra watt hours per year.

Typical HEE consists of:

Televisions (TVs)

Set Top Boxes (STBs)

VCRs (videocassette recorders)

DVD players (digital versatile disc)

DVD/VCR combinations

Video Game Consoles (e.g., Wii, Xbox, etc.)

Home Theatre in a Box (HTIB)

Phase 1 findings demonstrate that there is high potential for DR savings within the HEE industry. Lack of information on peripheral HEE such as VCR, DVD players, HTIB, etc. was also highlighted. And, there are no code requirements for this equipment.

Several strategies are proposed to achieve this demand reduction that includes:

Implementation of Smart Eye Sensors to adjust TV screen brightness

Remotely Enabled Energy Saving settings on TVs

Timed Operation of STBs

Plug all HEEs into a remotely addressable smart strip

Since there is no data available for acceptance rates of DR residential programs, an acceptance rate of 20% is assumed. Strategies proposed in this report project potential savings of 124 MW at a 20% acceptance rate in SCE service territory when appliances are switched from active to standby mode. Similar calculations performed statewide resulted in potential savings of approximately 400 MW.

All strategies are viable and can be incorporated into Title 20, but controls should be integrated into HEE to allow two-way communications to make them DR addressable. These strategies fall in line with the SCE SmartConnectTM initiative. It is recommended to:

Perform extensive research to establish load profiles of HEE.

Investigate technology ownership of HEE in SCE territory such as how many people own a plasma TV versus a rear projection TV, etc.

Field evaluation of customer response and feedback to proposed strategies in this report. This helps utilities better understand the likeliness of customers to enroll in DR programs targeting HEE.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for home entertainment equipment (HEE). It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to HEE.


Phase 1 of this potential three-phase effort addresses the DR potential for HEE; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for HEE; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for HEE.

This report reviews the findings from Phase 1 and estimates the DR potential for HEE. This phase entails assessing the demand reduction associated with HEE, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with HEE.

TECHNOLOGY DESCRIPTION Home entertainment equipment is a combination of audio and video components that can be played in a comfortable home environment. Usually people associate home entertainment equipment with home theatre systems or TVs. Although both are an essential part of a home theatre system, there are more components involved in a typical HEE which can include:

Televisions (TVs)

Set Top Boxes (STBs)

VCRs (videocassette recorders)

DVD players (digital versatile disc)

DVD/VCR combinations

Video Game Consoles (e.g., Wii, Xbox, etc.)

Home Theatre in a Box (HTIB)

There are other components in HEE which are excluded from this study due to their small contribution to the active mode power demand, as they tend to spend most of their time in standby mode. Examples include tuners, turn tables, and the like, or HEE integrated into one of the components listed above, (e.g., amplifiers, which are now considered an integral part of the HTIB).




CURRENT ENERGY CODE REQUIREMENTS This section covers energy efficiency standards for TVs, and audio and video equipment set forth by State, Federal, Energy Star, and the Consortium for Energy Efficiency (CEE).

California State Codes mandate energy efficiency standards for TVs and other audio video equipment, however; there are no Federal code requirements for TVs or any other component of home entertainment systems. The CEE and Energy Star have several efficiency tiers for TVs. Currently; the CEE does not have guidelines for audio and video equipment but are in the process of creating them. There are no code requirements or Energy Star guidelines for game consoles or HTIBs.

All calculated energy efficiency requirements from respective codes/guidelines for HEE are listed in Table 1 thru Table 4.

TELEVISIONS TABLE 1. ENERGY CODE REQUIREMENTS/GUIDELINES FOR TELEVISIONS

ENERGY STAR MAX. ON MODE

POWER (WATTS) FOR NON HIGH

DEFINITION TVS2

ENERGY STAR MAX. ON MODE

POWER (WATTS) FOR HIGH

DEFINITION TVS2

DIAGONAL

SCREEN

SIZE AREA

(SQ. INCHES)

SCREEN

AREA

(SQ. INCHES)

STATE

EFFICIENCY

CODE

REQUIREMENTS

IN STANDARD

STANDBY

MODE1

480 LINES OF

NATIVE

VERTICAL

RESOLUTION

768/1080

LINES OF

NATIVE

VERTICAL

RESOLUTION

480 LINES OF

NATIVE

VERTICAL

RESOLUTION

768/1080

LINES OF

NATIVE

VERTICAL

RESOLUTION 3 watts for

all screen sizes

20 170.5 45 66 66 37

32 438.0 78 120 120 46

42 754.0 115 208 208 55

50 1068.2 153 318 318 177

60 1537.6 210 391 391 188

TABLE 2. ENERGY CODE REQUIREMENTS FOR TELEVISIONS (CEE TIERS)

SCREEN SIZES 3

(DIAGONAL SQUARE

INCHES)

TIER 1

TIER 2

TIER 3

TIER 4

170.5 66 56 46 36

438 120 102 84 66

754 208 177 146 114

1068.2 318 270 222 175

1537.6 391 332 274 215


CONSUMER AUDIO AND DVD PRODUCTS According to Energy Star’s definition, all consumer audio and DVD products include equalizers, powered speakers, DVD players, DVD recorders, stereo amplifiers/pre-amplifiers, and tuners. See Table 3 for ENERGY STAR energy efficiency guidelines.

TABLE 3. ENERGY STAR EFFICIENCY GUIDELINES FOR CONSUMER AUDIO AND DVD PRODUCTS

PRODUCT

STATE EFFICIENCY CODE

MAXIMUM POWER

REQUIREMENTS IN

STANDBY MODE

(WATTS)4

PHASE 2* STANDBY

MODE POWER (WATTS)

Consumer Audio Products 2 (without permanently illuminated clock) 4 (with a permanently illuminated clock)

≤ 1.0

DVD Products 3 ≤ 1.0

*Phase 2 marks the implementation of energy efficiency guidelines, listed above, to be effective starting January 1, 2003.

SET-TOP BOXES Set-top boxes are classified as; cable, satellite, internet protocol (IP), terrestrial, thin client/remote. For the purposes of this report, energy consumption for cable and satellite STBs are listed in Table 4.

TABLE 4. ENERGY STAR EFFICIENCY GUIDELINES FOR SET-TOP BOXES

BASE FUNCTIONALITY

TIER 1* ANNUAL ENERGY

CONSUMPTION

(KWH/YR)5

TIER 2** ANNUAL

ENERGY CONSUMPTION

(KWH/YR)5

Cable 70 50

Satellite 88 56

*Tier 1 came into effect January 1, 2009.

** Tier 2 will become effective in 2011.

DEMAND PROFILE AND ENERGY CONSUMPTION Annual average energy used by electronic equipment in a California home is between 1,069 - 1,207 kWh6, costing homeowners approximately $150 per year. This energy consumption is 15% of all electric consumption in a typical California home. In 2008, estimated U.S. residential energy use was 113 TWh7 approximately 8% of residential electric energy use attributable to TVs and STBs and is growing at a rate of 2% per year. Projected energy consumption in 2009 for color TVs and STBs is 966 kWh7 per U.S. household. By year 2030, the total U.S. residential electric energy use for TV’s will be approximately 267 TWh8 per year.

Factors contributing to this increase in power demand include:



Growing number of TVs per household. Studies suggest that there are more TVs than occupants in the average household.

Increasing penetration for STBs due to service provider’s transmission format.

Increasing number of viewing hours to more than 8 hours per day.

Increasing screen viewing sizes, and

Demand for more functions and higher performance from HEE.

Plasma TVs, among all home entertainment equipment, are the top power draws grossing close to 246 W per unit followed by rear projection TVs which use 160 W per unit. DVD/VCR combo’s have the least power draw with 11.2 watts in active mode. Detailed power demand for various home entertainment equipment in active, low power/idle and standby mode are given in Table 5 below.

TABLE 5. POWER DRAW OF HEE IN VARIOUS MODES OF OPERATION

PRODUCT

ACTIVE

MODE

POWER

DRAW (W)

LOW POWER/IDLE

MODE POWER DRAW

(W)

STANDBY MODE

POWER DRAW

CRT 73.0 33.1 3.2

LCD 69.9 2.2

Plasma 245.9 0.9

Televisions

Rear Projection

159.9 45.7 3.2

Cable 16 15 Set-Top Box

Satellite 15.5 11.1 13.15

VCR 14.6 9.7 3.45

DVD Player 12.4 7.5 2

DVD/VCR 11.2 5.3 2.3

Game Console 30.1 30.1 1

HTIB 38 34 0.6

Power usage for satellite STBs, VCRs, DVD players, DVD recorders, and game consoles are the averages of power usage values from two different studies.9&10

MARKET SIZE SCE service territory has over 4.3 million11 customers and 96%12 of these customers own at least one TV set. Saturation levels for STBs and other peripheral equipment in home entertainment systems are assumed to be similar to TVs since information for these equipment types were not available. Using the 96% ownership rate, there are an estimated 4.1 million customers who own at least one TV and the related home entertainment peripheral equipment.

Overall, in the state of California, 99% of the households have at least one TV and related peripheral equipment. In other words, approximately 13.3913 million households in the state of California own HEE.



MARKET BARRIERS Barriers may include customer’s preference for a particular technology such as they may prefer a LED TV versus a LCD TV. Security and cost may also be a cause of concern for customers. Based on previous market research performed on this market segment, no overarching barriers such as health or food code requirements were determined.

DEMAND RESPONSE STRATEGIES AND POTENTIAL Since no data is available to accurately determine the number of HEEs in SCE service territory, it is assumed that every household owns at least one TV and STB to estimate demand reduction in SCE service territory as well as statewide.

For the purpose of this evaluation, the DR potential is defined in Equation 1.



STRATEGY 1 – IMPLEMENT SMART EYE SENSORS TO ADJUST TELEVISION SCREEN BRIGHTNESS

STRATEGY DESCRIPTION This strategy uses a remotely addressable camera sensor installed near the TV. When a DR event is called and the user is not viewing the TV, or if the ambient lighting conditions change, the camera sensor detects the change and adjusts the brightness level of the screen according to the user’s comfort level. For example, if the room is over lit, then the sensor reduces the brightness of the screen to a level that occupants can watch TV without compromising their comfort. Also, if a user falls asleep while watching TV, a camera sensor can detect no movement and dim the screen to a minimum brightness level; brightness is restored when the camera sensor detects motion.

TECHNICAL DEMAND REDUCTION This strategy can bring the power demand levels to as low as 10 watts when a TV screen is operating at minimum brightness level. Total demand reduction will vary depending upon the screen size and the technology that a particular TV uses, (e.g., LCD, rear projection, CRT, plasma, or LED). In a typical LCD TV, demand reduction is approximately 59.9 W. The highest savings are seen in plasma TVs (236 watts). An average demand reduction of 127 watts can be realized across all TV types.

MARKET ACCEPTANCE Foreseen barriers to the acceptance of this DR strategy may be customer’s perception and preferences. This strategy should have the least customer resistance, since it does not compromise customer comfort nor does it hinder recording operations. However,



customers may be hesitant of having a monitoring device attached to their HEE. Also customers may be skeptical about this methodology invading their private life. Based on these factors, estimations are made ranging from 1% to 50% acceptance.

DEMAND RESPONSE POTENTIAL DR potential for Strategy 1 is calculated using Equation 1:


Average Watt reduction across various TV technology types is used in this section. However, actual savings may vary by screen size and technology type, (e.g., plasma, rear projection, etc.).

Savings calculations for California and SCE service territory are shown at various acceptance levels in Table 6.

TABLE 6. STRATEGY 1 – DEMAND RESPONSE POTENTIAL AT VARIOUS ACCEPTANCE LEVELS FOR HEE

DR POTENTIAL (KW)

KW

REDUCTION/UNIT MARKET SIZE

(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE 0.127 SCE 4,172,719 5,307 26,533 53,067 106,133 265,333

CA 13,259,939 16,863 84,317 168,633 337,267 843,166

STRATEGY 2 – REMOTELY ENABLE ENERGY SAVING SETTINGS IN TELEVISIONS

STRATEGY DESCRIPTION This strategy remotely enables the energy savings settings available in TV menus through a RF or wireless device. These settings are typically not used by customers. Manufacturers also leave these settings disabled relying upon the user to turn them on. These settings save energy by reducing the screen refresh rate, contrast ratio, etc.

TECHNICAL DEMAND REDUCTION This strategy may reduce the power demand by 20 watts in plasma TVs. This reduction may vary by screen size and technology of TV (e.g., LCD, LED, or rear projection). For the purposes of this report 20 watts is used, however, an in-depth study for different TV types is recommended for this strategy.

MARKET ACCEPTANCE Foreseen barriers for acceptance of this DR strategy include user’s resistance to adopting this strategy as they may feel insecure about a third party controlling or monitoring their HEE; also there may be other issues such as safety etc. Various acceptance scenarios are demonstrated in Table 6.



DEMAND RESPONSE POTENTIAL DR potential for Strategy 2 is calculated using Equation 1.




DR POTENTIAL (KW)

KW


(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE 0.02 SCE 4,172,719 835 4,173 8,345 16,691 41,727

CA 13,259,939 2,652 13,260 26,520 53,040 132,599

STRATEGY 3 – TIMED OPERATION OF SET TOP BOXES

STRATEGY DESCRIPTION This strategy requires setting up a timer in a STB that enables the STB to come on during non-peak hours to perform routine updates. This timer can be triggered during a DR event and will keep the STB on standby mode until required by a user, or when the timer expires, whichever comes first. The timer enables the STB to come “ON” (if not ON already) at a preset time to perform data downloads that are required by the customer’s service provider.

TECHNICAL DEMAND REDUCTION Demand reduction for satellite STBs is 1 W and for cable STBs is 2.3 watts. On an average, this strategy saves 1.675 watts. Savings calculations are shown in the DR potential section of this report.

MARKET ACCEPTANCE Foreseen barriers for acceptance of this DR strategy include user’s preferences (e.g., user might be in the middle of recording their favorite show), switching the STB from active to standby mode may hinder this operation. Various acceptance rate scenarios have been illustrated in Table 8.







DR POTENTIAL (KW)

KW


(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE 0.0016 SCE 4,172,719 70 349 699 1,398 3,495

CA 13,259,939 222 1,111 2,221 4,442 11,105

STRATEGY 4 – PLUG ALL HOME ENTERTAINMENT EQUIPMENT INTO A REMOTELY ADDRESSABLE SMART STRIP

STRATEGY DESCRIPTION Plugging all HEE into a smart strip will turn all the idle devices running in active mode onto standby mode and all active devices into power save mode by changing the settings, e.g., setting bass and treble levels of HTIB to minimum, reducing the processing rate of game consoles, or by reducing the contrast on TV screens, etc.

TECHNICAL DEMAND REDUCTION Demand reduction for STBs is 1.675 watts, TVs account for 20 watts of power draw reduction and for game consoles reduction is approximately 1 watt, based on engineering judgment. Total demand reduction for this strategy is highly dependent on the number of components that are “ON” when a DR event is called. Depending on these factors, if every device in the HEE is “ON,” the demand drop is 226 watts; on the other hand, it is 0 watts if all devices are on standby. For the purposes of this study, assuming that at least STBs and TVs are set to “ON” at the time a DR event is called, savings will be 128.5 watts.

MARKET ACCEPTANCE The foreseen market barrier to acceptance of this DR strategy may be the user’s preferences, for example, a user might be in the middle of recording their favorite show. Switching the STB from active to standby mode may hinder this operation.







DR POTENTIAL (KW)

KW


(POPULATION)

AT 1%

MARKET

ACCEPTANCE

AT 5%

MARKET

ACCEPTANCE

AT 10%

MARKET

ACCEPTANCE

AT 20%

MARKET

ACCEPTANCE

AT 50%

MARKET

ACCEPTANCE 0.1285 SCE 4,172,719 5,366 26,831 53,661 107,322 268,306

CA 13,259,939 17,052 85,261 170,523 341,046 852,614

RESULTS Phase 1 evaluation of demand reduction for HEE, as seen in Tables 6 though 9 demonstrate that there is a high potential for DR strategies. Strategy 1 thru 3 can be implemented simultaneously by utilizing the same platform, this may result in potential savings of 124 MW at an estimated acceptance rate of 20% and for strategy 4, the overall calculated potential savings are 107 MW for TVs and STBs in SCE service territory. These strategies also fall in line with SCE SmartConnect initiative and the future vision to integrate DR into Title 20.

Audio/Video equipment such as DVD players, VCRs, etc. are also good DR potential candidates however these devices are believed to spend most of their time on standby mode. Data available for game consoles indicated that these devices, in idle mode draw almost the same amount of power as they do in active mode. Similar results were found for STBs in one of the studies. Therefore, such devices should be targeted in idle mode as well.

Cumulative power demand savings for SCE service territory and California are summarized in Table 10 below with corresponding market sizes.

TABLE 10. POTENTIAL DEMAND SAVINGS FOR HEE

MARKET SIZE OVERALL DR POTENTIAL

(MWS) OVERALL WATT

REDUCTION/UNIT SCE

SERVICE

TERRITORY

STATEWIDE

ESTIMATED

MARKET

ACCEPTANCE SCE

SERVICE

TERRITORY

STATEWIDE Strategy 1 0.127 4,172,719 13,259,939 20% 106.13 337.26

Strategy 2 0.02 4,172,719 13,259,939 20% 16.69 53.04

Strategy 3 0.0016 4,172,719 13,259,939 20% 1.39 4.44

Strategy 4 0.128 4,172,719 13,259,939 20% 107.32 341.04



Savings illustrated above are a result of strategies described in this report targeting TVs and STBs. However, if the demand reduction for all peripheral equipment such as DVD players, VCR’s, Game Consoles etc. is also realized, demand drop per unit can be approximately 226 watts (see strategy 4) and a cumulative potential for SCE territory can be more than 188 MW whereas for California it can be approximately 600 MW at 20% acceptance rate.

RECOMMENDATIONS Review of HEE and the average power demand based on previous research shows high DR potential exists as TV’s and STB alone are responsible for more than 8%7 of residential electric energy consumption. Demand for TV’s is growing at a rate of 2%7 per year and households now have more than one TV set in their homes.

Strategies discussed in this report are all viable and may be implemented without compromising the comfort and preferences of customers. This may result in a higher acceptance rate for these strategies and higher savings potential, but controls should be incorporated into the entertainment devices to allow two way communications to make them DR addressable. As a result, true DR potential may be more than 124 MW in SCE service territory for HEE and peripheral equipment.

Strategy 1 and 2 are targeted towards demand reduction in TVs. Field implementation of these strategies should be conducted on two separate test groups to understand customer response and also to confirm savings. Strategy 3 can be implemented as an extension of strategies 1 and 2 as STBs are now required for TVs in order to receive digital transmission. STB timers can be programmed to work in conjunction with current operating modes of TVs. Strategy 4 involves all HEE. Actual demand drop may be higher than projected in this report depending on the number of devices present in a household and are plugged into a smart strip. Table 9 depicts only the standard scenario of one TV and STB. In reality, devices such as gaming equipment, DVD players, etc. may also be present on the test site, or some households may have more than one TV or STB.

Number of studies/research performed on this segment of the residential market are very limited and do not provide accurate data for individual components of home entertainment system, for example, there is more emphasis on TVs and STBs than on HTIBs, DVD players, speakers, etc.

Further studies are also recommended to address these issues as well as a field evaluation to:

Establish load profiles of all components of home entertainment systems to calculate demand savings. Accurate knowledge of hours spent by each device in active mode will result in an accurate estimate of demand reduction savings.

Investigate the ownership rate of various technologies available for HEE (determine how many people own plasma TVs versus LCD TVs). Then accurate calculations and savings can be determined. Note: Power reduction is higher for plasma TVs when they are switched to run on standby.

Establish saturation levels of peripheral equipment as this data is not available for any HEE other than TV’s.

Survey customers on their likeliness to participate in DR programs targeting HEE; a field evaluation will help better understand customer response and feedback on the strategies proposed.



Next steps should also include field testing of these strategies to realize and confirm the projected 124 MW savings; followed by integrating the most viable strategy into the Title 20 appliance efficiency code in Phase 3.



Southern California Edison Page 13 Design and Engineering Services November 2009

REFERENCES

1 California Appliance Energy Efficiency Code Title 20, section 1605.3, Table V, p. 167 2 ENERGY STAR website:

http://www.energystar.gov/ia/partners/product_specs/program_reqs/tv_vcr_prog_req.pdf

3 Consortium for Energy Efficiency website:

http://www.cee1.org/files/CEEConsumerElectronicsProgramGuide.pdf 4 Ibid 1, Table V, p. 167 and Energy Star Website:

http://www.energystar.gov/index.cfm?fuseaction=products_for_partners.showHomeAudio 5 ENERGY STAR Website

http://www.energystar.gov/ia/partners/product_specs/program_reqs/set_top_boxes_prog_req.pdf 6 Final Field Research Report, Ecos Consulting, Oct 2006, p. 18


7 EPRI- Televisions and Set Top Box Energy Use, Technical Update, Sep 2008, p. 4-1 8 US Building Sector Energy Efficiency Potential, LBNL, Sep 2008, p. 2

http://enduse.lbl.gov/info/LBNL-1096E.pdf 9 ECEEE 2007 Summer Study, TIAX LLC, p. 1362

http://www.eceee.org/conference_proceedings/eceee/2007/Panel_6/6.360/ 10 Final Field research report, Ecos Consulting. Oct 2006, p. 62


11 Internal Communication, E-mail, Oct 2009, Portfolio Analysis, Measurement & Evaluation 12 California Statewide Residential Appliance Saturation Study. June 2004.

CEC-400-04-009, p. 4

http://websafe.kemainc.com/RASSWEB/uploads/RASS-ExecSummary-FINAL.pdf 13 U.S. Census Bureau, California QuickFacts, http://quickfacts.census.gov/qfd/states/06000.html,

accessed on November 6, 2009



http://www.cee1.org/files/CEEConsumerElectronicsProgramGuide.pdf

http://www.energystar.gov/index.cfm?fuseaction=products_for_partners.showHomeAudio

http://www.energystar.gov/ia/partners/product_specs/program_reqs/set_top_boxes_prog_req.pdf








INTEGRATION OF DR INTO TITLE 20 FOR LAPTOP BATTERIES AND DOCKING STATIONS Phase1: Demand Response Potential

DR 09.05.13 Report

Prepared by:


November 30, 2009


Introduction.....................................


DR Potential and Strategies................

Results............................................


References ......................................

1

2

5

5

6

7

8

Integration of DR into Title 20 for Laptop Batteries and Docking Stations DR 09.05.13


Acknowledgements

Southern California Edison’s Design & Engineering Services (DES) group is responsible for this project in collaboration with the Tariff Programs & Services (TP&S) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 09.05.13. DES project manager Neha Wadhera conducted this technology evaluation with overall guidance and management from Carlos Haiad of DES and Jeremy Laundergan of TP&S. For more information on this project, contact [email protected].

Disclaimer




EPS External Power Supply

kWh KiloWatt Hour

LAN Local Area Network

MW Mega Watt


TWh TeraWatt Hour

USB Universal Serial Bus



EXECUTIVE SUMMARY Batteries and docking stations contribute a 9% share of plug load energy consumption in the residential sector. This usage translates into 100kWh/yr per household in Southern California Edison (SCE) service territory. Residential electric energy use is estimated to grow at a rate of 2.4% per year as new and more efficient technologies become available to customers. This consumption can be reduced by implementing demand response (DR) strategies on these appliances.

DR strategies for laptop batteries and docking stations can lead to a potential demand reduction of 1.4 MWs in SCE service territory and approximately 4.3 MWs in California if 5% of the entire population adopts and implements the strategy proposed in this report. However, this number can increase if acceptance rates for this strategy increase.

One strategy proposed in this report is to force laptops to run on batteries until they drain to a low level. This low level can be defined either by the user or utility. When the battery level goes below a pre-established low level, the external power supply (EPS) of a laptop or docking station is triggered “ON” to provide power. This ensures that the laptop remains in Active mode during a DR event. This strategy can be implemented by using an automatic power management device/chip. This device monitors the battery level in real-time and triggers the EPS, when required.

Local Area Network cable or wireless internet networks present in a household can also be used to implement this strategy, however, they are limited in their capability to trigger the EPS of the laptop or docking station when the battery level is low. This strategy has the potential to be implemented without compromising the user’s expectation of high performance from their laptop computers.

DR savings calculated in this report seem promising. However, a closer look into this market segment is required to realize true DR potential. Therefore, Phase 2 is recommended in order to:

Determine time spent by laptops in various operational modes, (e.g., active, low/idle, and standby) as these may impact DR savings.

Establish market share of batteries and docking stations as these are categorized under miscellaneous plug load that include small appliances such as telephony, personal hygiene, etc.

Calculate and establish the load profile of such appliances.

Determine the total number of laptop batteries and docking stations contributing to the peak load demand in SCE service territory.



INTRODUCTION This project seeks to validate and establish demand response (DR) potential for laptop batteries and docking stations. It is part of a multi-phase, multi-year effort to evaluate the potential for DR to be incorporated into the California Appliance Efficiency Regulations (Title 20) for a series of 13 commercial and residential appliance categories from refrigerated display cases to laptop batteries and docking stations.


Phase 1 of this potential three-phase effort addresses the DR potential for laptop batteries and docking stations; if Phase 1 yields encouraging results, Phase 2 will demonstrate DR capabilities and strategies for batteries and docking stations; and if the demonstration is successful, Phase 3 will develop a Title 20 Codes and Standards Enhancement initiative to incorporate DR requirements for batteries and docking stations.

This report reviews the findings from Phase 1 and estimates the DR potential for batteries and docking stations. This phase entails assessing the demand reduction associated with batteries and docking stations, the population statewide and within SCE service territory, and the market/consumer acceptability of DR strategies associated with batteries and docking stations.

TECHNOLOGY DESCRIPTION Laptops are a mobile version of desktops that balance capability, performance and portability. These devices have the same basic components found in desktops such as a monitor, hard drive, keyboard and mouse. They are typically light weight and systems are powered from an external power supply (EPS) as well as a rechargeable battery. Batteries can support laptop’s power demand where power connections are not available, or if the power is out.

Laptops can use docking stations at a permanent work location to provide connectivity to multiple input/output ports and to expand the laptop’s capabilities, such as connectivity to printers, scanners, external hard drives, multiple monitors, etc. Essentially, a docking station converts a laptop into a desktop computer when required by the user.

CURRENT ENERGY CODE REQUIREMENTS Currently, there are no code requirements established for laptop batteries and docking stations by state or federal agencies. ENERGY STAR and the Consortium for Energy Efficiency do not provide any energy efficiency guidelines for laptop batteries or docking stations.

Some docking stations are sold with EPS attached to them. These EPSs are regulated by Title 20 and federal appliance energy efficiency code. Minimum efficiency requirements are listed in Table 11 and Table 21 below:




TABLE 1. ENERGY EFFICIENCY CODE REQUIREMENTS FOR EPS IN ACTIVE MODE

NAME PLATE OUTPUT

MINIMUM EFFICIENCY IN ACTIVE MODE FOR STATE AND FEDERALLY

REGULATED EPS*

<1 watt 0.5* Nameplate Output

≥ 1 watt and ≤51 watts 0.09* Ln(Nameplate output) +0.5

> 51 watts 0.85

TABLE 2. ENERGY EFFICIENCY CODE REQUIREMENTS FOR EPS IN NO-LOAD MODE

NAME PLATE OUTPUT

MAXIMUM ENERGY CONSUMPTION IN NO- LOAD MODE FOR

EPS *

≤ 250 watts (Federal Requirements)

0.5 watts

Any Output (State Requirements)

0.5 Watts

*Minimum Efficiency Standards effective as of July 1, 2008.

EPS for docking stations generally draw approximately 26 watts in active mode and are required to have minimum efficiency of 0.793 in active mode and 0.5 watts in no-load mode.

DEMAND PROFILE AND ENERGY CONSUMPTION A typical California household consumes 1,000 – 1,2002 kWh/yr in plug load. This electricity consumption is 15% -17%2 of the overall electricity consumption of a household and can cost approximately $1502 per year. EPS and docking stations constitute 9%3 of plug load energy consumption, (e.g., approximately 100kWh/yr per US household). Power demand of laptop batteries and docking stations in different operational modes is listed in Table 3.

TABLE 3. POWER DRAW BY MODE FOR LAPTOP BATTERIES AND DOCKING STATIONS

EQUIPMENT

ACTIVE MODE

POWER DRAW

(W)

LOW

POWER/IDLE

MODE POWER

DRAW (W)

STANDBY MODE

POWER DRAW (W)

Laptop Batteries 23 2.55 1.5

Docking Stations** 26 1.2 0

Demand for laptop batteries is assumed to be equivalent to that of the laptop computer as batteries are an integral part of laptops and are used as a substitution for EPS. Power demand for laptops is a calculated average of power demand values from two studies.4&5

Active mode demand for docking stations is equivalent to the sum of laptop power demand and the EPS of the docking station since a docking station is active when a laptop is docked and is operated by a user.

** These power demand values are a result of tests performed by D&ES on a sample of 3 docking stations.


MARKET SIZE There are 3.66 million laptop units in households statewide. The number of laptop units in SCE service territory is proportional to the ratio of number of households in SCE service territory (approx. 4.37 million) and to the number of households statewide (approx. 13.398 million). This ratio, when applied to the number of laptops statewide, results in the total number of laptop units in SCE service territory which is approximately 1.2 million laptop units. These figures are based on the assumption that each household has only one laptop.

MARKET BARRIERS There are no health or food code barriers for this technology type. However, there may be market acceptance and performance issues related to this proposed strategy.

DEMAND RESPONSE STRATEGIES AND POTENTIAL Currently laptop battery chargers and docking stations have 9%3 share of plug load residential energy consumption. Residential energy usage is continuously increasing at a rate of 2.4%9 per year from 1996-2030. By year 2030, personal computers (laptops and desktops) will be responsible for 68TWh10 of energy use in the United States.

For the purpose of this evaluation, the DR potential is defined in Equation 1.



STRATEGY – FORCE LAPTOP TO RUN ON BATTERIES

STRATEGY DESCRIPTION This strategy uses an automatic power management device (maybe a chip) on an EPS of a laptop or docking station. When a DR event occurs this device disconnects the power supply from the EPS and allows the laptop to run on its battery. This device continuously monitors battery status of the laptop and forces the EPS to power ON if the battery level falls below a certain level. This level is pre-established either by the user or utility. For example, when a remaining battery charge is 20%, the power management device triggers the EPS to power ON and allows the laptop/docking station to remain in Active mode.

In cases where the customer chooses not to participate in the DR event, they have full control and can override utility requests and continue to work as normal.

This strategy can also use LAN or wireless networks, whichever is usually available in a residence to turn off the laptop/docking station’s EPS when a DR event is called. The signal sent by the utility disconnects the EPS and allows the laptop/docking station to run on its battery. If the battery status is critically low when a DR event is called, the user can override the DR request manually. However, a wireless network or LAN can only be used to send DR requests and are limited in their capability to automatically power ON the EPS when the battery level is low.



TECHNICAL DEMAND REDUCTION This strategy may result in 26 watts reduction in docking stations and 21.5 watts in laptop batteries. Overall, an average savings potential as a result of implementing this strategy is approximately 23.75 watts as shown in Table 1.

MARKET ACCEPTANCE Foreseen barriers to acceptance of this DR strategy include costs associated with implementing an automatic power management device. Some users may not like the idea of adding another device to their existing set up. Moreover, users may be skeptical of their system underperforming if this strategy is implemented. Cyber security may also be a concern for users. Based on these factors a 5% acceptance rate is assumed.

DEMAND RESPONSE POTENTIAL DR potential for this strategy is calculated using Equation 1. This equation factors in the market size, kW demand reduction per unit to calculate gross demand reduction in SCE service territory and statewide. However, this reduction is dependent on the number of users willing to implement this strategy. Thus, a market acceptance factor is taken into account to calculate net demand reduction in SCE service territory and statewide. DR potential calculated at various acceptance rates is listed in Table 4.

TABLE 4. DR POTENTIAL AT VARIOUS ACCEPTANCE LEVELS FOR LAPTOP BATTERIES AND DOCKING STATIONS

DR POTENTIAL (KW) KW

REDUCTION

/UNIT MARKET SIZE (POPULATION)

AT 1% ACCEPTANCE

AT 5% ACCEPTANCE

AT 10% ACCEPTANCE

AT 20% ACCEPTANCE

AT 50% ACCEPTANCE

0.024 SCE 1,168,272 277 1,387 2,775 5,549 13,873

0.024 CA 3,600,000 855 4,275 8,550 17,100 42,750

RESULTS The strategy discussed in this report provides an opportunity for DR programs in SCE service territory, and can be implemented on laptop batteries and docking stations as discussed earlier. This strategy, can lead to higher potential savings if more than 5% of the population (1.5 million), in SCE service territory implement this strategy on their laptops or docking stations.

Overall DR potential for laptop batteries and docking stations at 5% acceptance rate in SCE service territory and statewide are summarized in Table 5.

TABLE 5. POTENTIAL DR SAVINGS FOR LAPTOP BATTERIES AND DOCKING STATIONS

MARKET SIZE OVERALL DR POTENTIAL (MW) OVERALL KW

REDUCTION/UNIT SCE STATEWIDE ESTIMATED MARKET

ACCEPTANCE SCE STATEWIDE 0.024 1,168,272 3,600,000 5% 1.4 4.3



RECOMMENDATIONS This strategy has the potential to be implemented on a small demo user group to evaluate actual DR potential and as discussed in this report is viable and may be implemented; but controls should be incorporated into laptops and docking stations to make them DR addressable.

Strategy for laptop batteries and docking stations has an overall potential savings of 1.4 MW in SCE territory and 4.3 MW statewide at the acceptance rate of 5% but these savings can increase if more households adopt the strategy proposed. However, there are no studies done to establish power demand data for laptop batteries and docking stations. For years, personal computers and monitors have been the focus of research performed in this market segment since docking stations are relatively new to the residential market. Therefore, it is recommended to:

Perform field studies to determine time spent by laptops in various operational modes, (e.g., active, low/idle and standby modes and the corresponding power usage). These findings may affect the cumulative savings seen in this report for SCE service territory and statewide.

Establish the market share of batteries and docking stations as this market segment is fairly new and offers a DR opportunity. These appliances are typically categorized under miscellaneous plug load that includes small appliances such as telephony, personal hygiene, etc. Thus, an accurate market share of such appliances should be established.

Calculate and establish the load profile of laptop batteries and docking stations.

Determine the total number of laptop batteries and docking stations contributing to the peak load demand in SCE service territory.

A Phase 2 evaluation is highly recommended to evaluate customer response and feedback on the strategy proposed.




REFERENCES

1 California Appliance Energy Efficiency Code, Title 20, Table U-1, pg-134, Table U-3, p. 167 2 Technical Brief, Energy Use of Household Electronics: Taming the Wild Growth, PIER, Sep 2008, p. 1

www.energy.ca.gov/research 3 Ibid, p. 1 4 ECEEE 2007 Summer Study, Residential Consumer Electronics Electricity Consumption in United

States, Kurt Roth and Kurtis McKenney TIAX LLC, p. 1362

http://www.eceee.org/conference_proceedings/eceee/2007/Panel_6/6.360/ 5 Final Field Research Report, Ecos Consulting, Oct 2006, p. 62


6 Energy Information Administration Website: http://www.eia.doe.gov/emeu/recs/recs2005/hc2005_tables/hc11homeelectronics/pdf/tablehc15.11.pdf

7 Southern California Edison Customer Database, Southern California Edison, accessed on Oct 2009 8 U.S. Census Bureau, California QuickFacts, http://quickfacts.census.gov/qfd/states/06000.html,

accessed on November 6, 2009 9 U.S. Building Sector Energy Efficiency Potential, Environmental Energy Technical Divisions,

Rich Brown, Sam Borgeson, Jon Koomey, Peter Biermayer for LBNL, Sep 2008, pg-1

http://enduse.lbl.gov/info/LBNL-1096E.pdf 10 Ibid,Table-1 (for personal computers), pg-2




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