evaluation results of the 2004 & 2005 california statewide energy star® new homes program clark...

Evaluation Results of the 2004 & Evaluation Results of the 2004 & 2005 2005

California Statewide California Statewide ENERGY STAR® New Homes ENERGY STAR® New Homes

ProgramProgram

Clark BernierClark Bernier

Presented at the October 17, 2007 Presented at the October 17, 2007 CALMAC MeetingCALMAC Meeting

CALMAC October 2007 2

Total Buildings Built Under Total Buildings Built Under ProgramProgram

Utility Inland Coastal TotalPGE 11,117 1,192 12309SCE 13,145 152 13297SoCalGas 1,191 0 1191SDGE 1,256 3,060 4316TOTAL 26,709 4,404 31113

Utility Coastal Inland TotalPGE 171 204 375SCE 62 96 158SCG 80 548 628

SDGE 1,349 315 1,664Total 1,662 1,163 2,825

Single Family

Multi Family


Inspection Findings Inspection Findings Water Heating EfficiencyWater Heating Efficiency

Hot Water Energy Factor: Planned vs. Inspected

0.55

0.56

0.57

0.58

0.59

0.60

0.61

0.62

0.63

0.64

Home ID

En

erg

y F

acto

r

PlannedInspected

Site Inspection

s


Inspection Findings Inspection Findings AC EfficiencyAC Efficiency

Cooling SEER: Planned vs. Inspected

8

9

10

11

12

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14

15

Home ID

SE

ER

PlannedInspected

Site Inspection

s


Inspection Findings Inspection Findings Window AreaWindow Area

Total Window Area: Planned vs. Inspected

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Home ID

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do

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PlannedInspected

Average Planned Window Area: 420Average Installed Window Area: 395

Site Inspection

s


Inspection FindingsInspection FindingsOther MeasuresOther Measures

Measure Planned Inspected Frequency Net Energy EffectNo Yes 0Yes No 0No Yes 4Yes No 0

92

TXV Valve

Radiant Barrier

Attic R-value

No Difference

More Efficient

More EfficientHigher than planLower than plan

Site Inspection

s


Meter-to-Model Meter-to-Model Results:Results:

SF CoolingSF Cooling

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10

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Real-Weather Modeled Site Annual Cooling kWh (log scale)

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tere

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Co

oli

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kW

h (

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Coastal SitesDesert

Sites

Meter-to-Model

Analysis


Meter-to-Model Meter-to-Model ResultsResults

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Real-Weather Modeled Site Annual Heating kBtu

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Real-Weather Modeled Site Annual Water Heating kBtu

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ter

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SF HeatingSF Heating SF Water SF Water HeatingHeating

Meter-to-Model

Analysis



SF Ratio ResultsSF Ratio Results

Coastal 14 1.752 49.0%Inland 72 0.797 14.3% *Desert 5 0.664 18.3% *

Coastal 14 0.589 28.9% *Inland 76 0.614 11.6% *Desert 6 0.837 25.3%

Hot Water N/A 87 0.813 10.3% *

* Indicates statistically significantly different from ratio = 1

Climate Sample nRatio Meter

Usage to Modeled Usage

Relative Precision

AC

Heat

End Use

Cooling: Coastal is 175% of model, inland is 66% - 80% of Cooling: Coastal is 175% of model, inland is 66% - 80% of modelmodel

Heating: actual is 59% - 61% of modelHeating: actual is 59% - 61% of model Water Heating: actual is 81% of modelWater Heating: actual is 81% of model

Savings Impact: 18% lower kWh, 20% lower Savings Impact: 18% lower kWh, 20% lower thermstherms

Meter-to-Model

Analysis


Meter-to-Model Meter-to-Model ConclusionsConclusions

Compliance models overstate usage Compliance models overstate usage (and thus savings)(and thus savings)

Why? Single FamilyWhy? Single Family It’s the people. Thermostat set point too high? Understate the average floor area per

person?

Meter-to-Model

Analysis


Single Family Net-to-Single Family Net-to-Gross ResultsGross Results

PGE 3,974,754 6,622,261 1.67 PGE 669,313 551,485 0.82 SCE 10,117,361 12,412,735 1.23 SCE 220,998 70,427 0.32

SoCalGas 2,078,956 1,760,013 0.85 SoCalGas NA NA NA SDGE 674,708 727,800 1.08 SDGE 831,500 668,434 0.80

TOTAL 16,845,778 21,522,809 1.28 TOTAL 1,721,811 1,290,346 0.75

Electricity (kWh)

UtilityInland

UtilityCoastal

Ex Post Gross Savings

Ex Post Net Savings

Net-to-Gross Ratio


Ex Post Net Savings

Net-to-Gross Ratio

Electricity NtG tends to be >1 inlandElectricity NtG tends to be >1 inland Gas NtG results are <1 everywhereGas NtG results are <1 everywhere Due to builder trade-offs in the baseline (greater inland)Due to builder trade-offs in the baseline (greater inland)

More efficient water-heatersMore efficient water-heaters Less efficient AC performanceLess efficient AC performance

PGE 1,053,484 588,538 0.56 PGE 114,116 1,077 0.01 SCE 1,006,054 336,590 0.33 SCE 3,912 -74 (0.02)

SoCalGas 55,012 22,154 0.40 SoCalGas NA NA NA SDGE 95,741 28,194 0.29 SDGE 205,031 43,107 0.21

TOTAL 2,210,291 975,476 0.44 TOTAL 323,059 44,110 0.14

Gas (therms)

UtilityInland

UtilityCoastal


Ex Post Net Savings

Net-to-Gross Ratio


Ex Post Net Savings

Net-to-Gross Ratio

Net-to-Gross


Single Family Savings per Single Family Savings per Unit: Comparison Across Unit: Comparison Across

Analysis StepsAnalysis Steps

Single Family kWh Savings per Unit

0100200300400500600700800

Gross Meter-AdjustedGross

Net

kW

h/u

nit s

avin

gs

Single Family Gas Therms Savings per Unit

020406080

100120140160


Net

The

rms/

unit

sav

ings

Net-to-Gross


Single Family Final Single Family Final ResultsResults

Ex Ante numbers based on per-unit estimates and # Ex Ante numbers based on per-unit estimates and # units builtunits built

High kWh Inland NtG results in high realization ratesHigh kWh Inland NtG results in high realization rates Low therms NtG results in low realization ratesLow therms NtG results in low realization rates Total Savings:Total Savings:

21.5 Million inland kWh, 2.3 Million coastal kWh21.5 Million inland kWh, 2.3 Million coastal kWh 975,000 inland therms, 44,110 coastal therms975,000 inland therms, 44,110 coastal therms

Final

PGE 2,929,935 6,622,261 596 2.26 PGE 327,638 551,485 463 1.68 SCE 13,218,550 12,412,735 944 0.94 SCE NA 70,427 463 NA

SoCalGas 841,921 1,760,013 1,478 2.09 SoCalGas 0 NA NA NA SDGE 812,883 727,800 579 0.90 SDGE 1,980,432 668,434 218 0.34

TOTAL 17,803,289 21,522,809 806 1.21 TOTAL 2,308,070 1,290,346 293 0.56

Electricity (kWh)Inland Coastal

Net Unit Savings

UtilityUtility Net Ex Ante

Net Ex Post Savings

Realization Rate

Net Ex Ante

Net Ex Post Savings

Realization Rate

Net Unit Savings

PGE 1,153,676 588,538 53 0.51 PGE 127,330 1,077 0.9 0.01 SCE NA 336,590 26 NA SCE NA -74 -0.5 NA

SoCalGas 29,394 22,154 19 0.75 SoCalGas 0 NA NA NA SDGE 19,694 28,194 22 1.43 SDGE -13,709 43,107 14 -3.1

TOTAL 1,202,764 975,476 37 0.81 TOTAL 113,621 44,110 10 0.39

Net Unit Savings

Gas (therms)Inland Coastal

Utility Net Ex Ante

Net Ex Post Savings

Realization Rate

Utility Net Ex Ante

Net Ex Post Savings

Realization Rate

Net Unit Savings


SF Billing Analysis SF Billing Analysis Results Results

Therms, Climate Zone 12Therms, Climate Zone 12

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Orientation-AdjustedGross

Ex Post Gross Ex Post Net Billing

ther

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Billing Analysis

Per-unit Therms Savings, Per-unit Therms Savings, by Analysisby Analysis


SF Billing Analysis SF Billing Analysis Results Results

kWh, Climate Zone 12kWh, Climate Zone 12

-300

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-100

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Orientation-Adjusted

Gross

Ex Post Gross Ex Post Net Billing

kW

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Billing Analysis

Per-unit kWh Per-unit kWh Savings, by AnalysisSavings, by Analysis


Inspection FindingsInspection FindingsMulti FamilyMulti Family

Site Inspection

s

ID

Heating Efficiency Tracking

Heating Efficiency Verified

Heating Efficiency

Type

Heating System Type

Cooling Efficiency Tracking

Cooling Efficiency Verified

DHW EF - Tracking

DHW EF - Verified

7.0 7 HSPF HPSplit 12 12 RE 0.82 N/O0.80 0.81 AFUE Hydronic 10 12 DHW 0.61 Boiler 0.857.8 7.8 HSPF HPSplit 10 10 0.00 Inst 0.81

0.75 0.78 AFUE Hydronic 10 10 0.62 0.600.75 0.75 AFUE Hydronic 10 10 0.61 0.610.75 0.78 AFUE Hydronic 10 10 0.60 0.600.76 0.75 AFUE Hydronic 10 10 0.62 0.620.75 0.75 AFUE Hydronic 10 10 0.54 0.54

No EF 0.70 AFUE Hydronic 10 10 0.58 0.600.75 0.75 AFUE Hydronic 10 10 0.60 0.620.78 0.75 AFUE Hydronic 10 10 0.62 0.620.79 0.75 AFUE Hydronic 10 10 0.61 0.626.8 N/O HSPF Room HP 10.66 N/O DHW 0.62 Boiler 0.82

0.78 0.75 AFUE Hydronic No cooling No cooling 0.56 0.590.80 0.76 AFUE Hydronic No cooling No cooling 0.59 0.580.82 0.74 AFUE Hydronic 12 12 0.63 0.62

No EF N/O AFUE Hydronic 11 N/O 0.62 0.557.8 N/O HSPF HPSplit 12.5 12 0.53 0.58

No EF N/O AFUE Hydronic 12 12 0.61 0.62No EF 0.80 HSPF HPSplit 10 10 0.64 0.62

0.80 0.80 AFUE FAU No cooling No cooling 0.62 0.620.80 N/O AFUE FAU No EF 10 0.60 N/O0.80 N/O AFUE FAU 10 11 0.60 N/O

EF - Energy factor DHW - Standard domestic hot water heaterNo EF - No efficiency recorded in tracking Boiler - Central boilerRE - Recovery efficiency Inst - Instantaneous hot water heaterN/O - Not observable

Hom

e I

D's

Suppre

ssed



MF CoolingMF Cooling

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Real-Weather Modeled Site Annual Cooling Source Kbtu (log scale)

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Meter-to-Model

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Real-Weather Modeled Site Annual Heating Source KBtu

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Real-Weather Modeled Site Annual Water Heating Source KBtu

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MF HeatingMF Heating MF Water MF Water HeatingHeating

Meter-to-Model

Analysis



MF Ratio ResultsMF Ratio Results

Coastal 6 0.118 77.5% *Inland 15 0.397 45.8% *Coastal 10 0.161 36.0% *Inland 12 0.212 68.8% *

Hot Water NA 22 0.301 25.2% * * Indicates statistically significantly different from ratio = 1

Sample n

AC

Heat

Ratio Meter Usage to

Modeled Usage

Relative Precision

ClimateEnd Use

Cooling: actual is 12% - 40% of modelCooling: actual is 12% - 40% of model Heating: actual is 16% - 21% of modelHeating: actual is 16% - 21% of model Water Heating: actual is 30% of modelWater Heating: actual is 30% of model

Savings Impact: 69% lower kWh, 73% lower Savings Impact: 69% lower kWh, 73% lower thermstherms

Meter-to-Model

Analysis


Meter-to-Model Meter-to-Model Conclusions…MFConclusions…MF

Compliance models overstate usage (and Compliance models overstate usage (and thus savings)thus savings)

Why? MultifamilyWhy? Multifamily Multifamily models fail to account for key

differences between SF and MF Occupancy patterns Economic differences Zonal comfort instead of whole-area

Ignores interaction between spaces In general: Multifamily structures are more

complex than Single Family, but treated the same

Meter-to-Model

Analysis


Multi Family Family Multi Family Family Net-to-Gross ResultsNet-to-Gross Results

SERA conducted interviews with SERA conducted interviews with buildersbuilders

Self-reported NtG ratioSelf-reported NtG ratio Final ratio used: Final ratio used: 0.500.50

Net-to-Gross


Multi Family Savings per Multi Family Savings per Unit: Comparison Across Unit: Comparison Across

Analysis StepsAnalysis Steps

Net-to-Gross

Multi Family kWh Savings

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Multi Family kWh Savings

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ar/u

nit

Single Family kWh Savings per Unit

0100200300400500600700800


Net

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avin

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Single Family Gas Therms Savings per Unit

020406080

100120140160


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Multi Family Final Multi Family Final ResultsResults

Realization rates are very lowRealization rates are very low Lower-than-expected NtG of 0.5Lower-than-expected NtG of 0.5 Large overstatement of usage/savings by tracking Large overstatement of usage/savings by tracking

modelsmodels

Final

PGE 309,584 79,929 0.26 PGE 171,991 6,673 0.04 SCE 494,614 111,230 0.22 SCE 199,786 8,195 0.04

SoCalGas 1,752,205 310,535 0.18 SoCalGas 103,934 3,776 0.04 SDGE 472,402 65,258 0.14 SDGE 1,658,253 47,500 0.03

TOTAL 3,028,806 566,952 0.19 TOTAL 2,133,965 66,144 0.03

PGE 103,540 15,538 0.15 PGE 57,522 10,061 0.17 SCE 0 16,971 NA SCE 0 5,665 NA

SoCalGas 176,653 44,445 0.25 SoCalGas 10,478 2,548 0.24 SDGE 47,626 15,289 0.32 SDGE 167,181 45,281 0.27

TOTAL 327,820 92,243 0.28 TOTAL 235,182 63,556 0.27

CoastalNet Ex Ante

Net Ex PostRealization

RateNet Ex Ante


RateUtility

InlandUtility

Realization Rate

Gas (therms)

Utility UtilityNet Ex Ante


Rate

CoastalInlandElectricity (kWh)

Net Ex Ante

Net Ex Post


Total Program ResultsTotal Program Results

Includes high-rise (not shown in this presentation)Includes high-rise (not shown in this presentation) 23.7 Million kWh, 1.26 Million Therms, 25.5 MW savings 23.7 Million kWh, 1.26 Million Therms, 25.5 MW savings Realization rates are highly variable between untilitiesRealization rates are highly variable between untilities

Different ex ante methods (2.5x - 4.5x PG&E per-Different ex ante methods (2.5x - 4.5x PG&E per-unit kWh estimates from the other IOUs) unit kWh estimates from the other IOUs)

Different mixes of coastal/inlandDifferent mixes of coastal/inland

Final

Net ExAnte

Net ExPost

RealizationRate

Net Ex Ante

Net Ex Post

RealizationRate

Net Ex Ante

Net Ex Post

RealizationRate

PGE 3,786,119 7,241,155 1.91 1,457,778 634,533 0.44 4,170 7,686 1.84 SCE 14,038,346 12,694,362 0.90 NA 371,772 NA 17,980 13,730 0.76

SoCalGas 2,874,807 2,050,545 0.71 234,344 97,608 0.42 4,194 2,202 0.53 SDGE 5,139,179 1,755,755 0.34 242,489 151,521 0.62 8,141 1,886 0.23 Total 25,838,451 23,741,818 0.92 1,934,611 1,255,434 0.65 34,485 25,504 0.74

kWh Therms kWUtility


Program Conclusion and Program Conclusion and Recommendations - IRecommendations - I

What do builders do to achieve savings vis-à-vis non-What do builders do to achieve savings vis-à-vis non-participantsparticipants 90% homes have tight ducts/infiltration90% homes have tight ducts/infiltration

Not tested for in the baselineNot tested for in the baseline Not generally claimed in non-participant homes Not generally claimed in non-participant homes

(even though they might qualify for the measure)(even though they might qualify for the measure) Billing results from CZ 12 offer some Billing results from CZ 12 offer some

corroboration that net savings might be even corroboration that net savings might be even lowerlower

Reduction in window areaReduction in window area (slightly) Higher equipment efficiencies(slightly) Higher equipment efficiencies Radiant barrierRadiant barrier OverhangsOverhangs Re-circulation timers on hot water systemsRe-circulation timers on hot water systems


Program Conclusion and Program Conclusion and Recommendations - IIRecommendations - II

Coastal impacts might not be worth the costCoastal impacts might not be worth the cost Realization rates are somewhat misleading as Realization rates are somewhat misleading as

IOUs used different methods to compute ex ante IOUs used different methods to compute ex ante savings savings

Builders don’t always do what’s modeledBuilders don’t always do what’s modeled Occupants don’t behave as modeledOccupants don’t behave as modeled Orientation has a large (17% - 25%) impact on Orientation has a large (17% - 25%) impact on

usage/savingsusage/savings Significant savings to be had by using the Significant savings to be had by using the

“best” orientation“best” orientation Significant need to make sure the registries Significant need to make sure the registries

record the actual orientation instead of just record the actual orientation instead of just the worstthe worst


Program Conclusion and Program Conclusion and Recommendations - IIIRecommendations - III

Compliance models alone are a poor indicator Compliance models alone are a poor indicator of usage/savingsof usage/savings Compliance-focused rather than modeling-Compliance-focused rather than modeling-

focusedfocused Methods (including ex ante) must take this Methods (including ex ante) must take this

into accountinto account Baseline studies need to be paired with Baseline studies need to be paired with

evaluation studies so that they are evaluation studies so that they are complimentarycomplimentary This means better-funded baseline studies This means better-funded baseline studies

are necessary to properly quantify program are necessary to properly quantify program savingssavings


Program Conclusion and Program Conclusion and Recommendations - IVRecommendations - IV

Improved tracking database(s)Improved tracking database(s) Consistent data formatConsistent data format Restricted entries on fields (many 2x, 3x Restricted entries on fields (many 2x, 3x

builder name spelling variations, etc.)builder name spelling variations, etc.) Record the details of failures – can find lost Record the details of failures – can find lost

savings opportunitiessavings opportunities


Contact InformationContact Information

Clark BernierClark BernierRLW AnalyticsRLW Analytics1055 Broadway, Suite G1055 Broadway, Suite GSonoma, CA 94576Sonoma, CA 94576

Phone: (707) 939-8823 x19Phone: (707) 939-8823 x19Email:Email:

[email protected]@rlw.comWeb:Web: http://www.rlw.comhttp://www.rlw.com

evaluation results of the 2004 & 2005 california statewide energy star® new homes program clark...

Documents

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analysis stepsnet

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lower kwh

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