lawrence berkeley national laboratory san francisco | solar + … · 2017-11-28 · lawrence...

Lawrence Berkeley National Laboratory San Francisco | Solar + Storage for Resilience

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Disclaimer: This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of California.


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Acknowledgements: This work was supported by the U.S. Department of Energy under Award No. DE-EE0006906, and also by the Assistant Secretary for Energy Efficiency and Renewable Energy, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Thanks to San Francisco Department of the Environment and Arup for partnering with us on this project. The project team at Lawrence Berkeley National Laboratory would like to thank our sponsor, Matter of Trust. We thank Lisa Gautier and Betty Cheng for providing us with the opportunity to do this work. Thank you, Laura Tam, and others at SPUR -- it was refreshing and fun to share space with different organizations for a day. We’d also like to thank our workshop participants for their enthusiastic participation in this workshop and research. Thanks to our reviewers for their generosity and time improving this report. Thanks, also, to the various industry professionals who shared their ideas and feedback for this project. Thanks to the many individuals who contributed to this work including Lawrence Berkeley National Laboratory (LBNL) staff, especially Paula Ashley, Ellen Thomas, Jerri Carmo, and Betsy Quayle.


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Abstract: Currently the vast majority of rooftop solar systems in the country cannot operate in an emergency when the grid is down. This report summarizes the results of a U.S. Department of Energy-sponsored workshop on the potential to retrofit the 6,500 existing photovoltaic (PV) systems within San Francisco to increase widespread availability of emergency power during a disaster. Technical solutions were assessed for both the short term (e.g., replacing an end-of-life inverter with one capable of providing minimal off-grid power under daylight) and long term (e.g., adding AC-coupled battery systems or rewiring to create DC-coupled battery systems). Motivational, financial, and regulatory barriers were assessed for four different types of buildings owners: residential, commercial, municipal, and nonprofit. Potential pathways were identified to overcome each barrier. While designed for San Francisco, most of the identified barriers and proposed solutions would apply to the vast majority of American municipal districts planning for increased resilience.


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Table of Contents: 1. Introduction 1 1.0 San Francisco Solar + Energy Storage for Resilience Project 1 1.1 Building Types 2 1.2. San Francisco Case Study 3

2. Technical Solutions for Retrofitting Solar Systems to Provide Resilience 4 2.0 Interactive System Disconnect 4 2.1 Electric Storage 4

3. Barriers to Implementation 6 3.0 Motivation 6 3.1 Finances 6 3.2 Regulatory 7

4. Strategies to Overcome Barriers 7 4.0 Motivational Strategies 7 4.1 Financial Strategies 8 4.2 Regulatory 9

5. Summary 9

APPENDIX A -‐ San Francisco | Solar + Storage for Resilience Workshop -‐ List of Participating Organizations

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APPENDIX B -‐ Spurring Solar + Storage for Resilience -‐ Detailed Notes

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1. Introduction Interest in energy resilience grows as our energy systems age, devastating storms become more common, and other natural disasters become more predictable. In the wake of Hurricane Sandy, many building owners were surprised to learn that their rooftop solar photovoltaic (PV) panels failed to operate when the power grid was down. The vast majority of rooftop PV units in America don’t operate when power is down for two main reasons. First, most PV systems use inverters that rely on the grid for voltage and frequency support, are interconnected to protect the grid and shut down when the power is lost, and utilize the grid for accepting excess power. Second, the potential for a PV system to supply electricity to a downed grid can lead to significant safety risks. However, it is possible to retrofit these systems to enable islanding and provide electricity during an emergency. This report summarizes the results of a workshop in San Francisco to do just this -- and boost community resilience and energy security in a disaster.

1.0 San Francisco Solar + Energy Storage for Resilience Project The workshop described in this report was one element of the "San Francisco Solar + Energy Storage for Resilience" project, which aimed to serve as a national model for integrating solar and energy storage into a city’s emergency preparation and response plans. The larger project conducted neighborhood-level planning to develop resilient power solutions at critical neighborhood facilities in communities throughout the city. Project staff created a map of critical facilities and selected priority sites, assessed critical loads, developed an online tool to size PV and batteries to serve the critical loads, designed site-specific plans, identified financing strategies, and developed a roadmap with best practices. 1.0.0 Solar + Storage for Resilience Workshop. This project element, the “San Francisco | Solar + Storage for Resilience Workshop,” was held on December 16, 2016 in San Francisco, CA. The purpose of the workshop was to explore the untapped potential of existing PV systems within San Francisco to provide resilient power, and to create a blueprint to upgrade/retrofit PV systems for islanding to boost community resilience and energy security in a disaster. To this end, the workshop sought to explore three main areas:

1. Identify technical solutions for retrofitting existing solar systems to provide resilient power in residential, businesses, nonprofits, municipal building sectors; 2. Identify barriers to implementation for each solution; 3. Explore market and policy drivers to encourage retrofits.

There were 38 workshop participants whose backgrounds spanned solar installers, battery manufacturers, engineers, architects, building control systems representatives, codes and standards developers, finance consultants, and representatives from the electrical worker union, universities, a national laboratory, the electric utility, multiple


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City and County of San Francisco departments, California Energy Commission, and the U.S. Department of Energy. (Appendix A includes a list of participating organizations.) Workshop participants identified obstacles, technical pathways, and implementation strategies for retrofitting rooftop PV in the residential, commercial, municipal, and nonprofit sectors. The work in San Francisco can offer ideas for uptake and adaptation by more than 19,000 local governments nationwide looking to improve their disaster resilience.

1.1 Building Types Four types of urban building PV installations have different capabilities to aid in a city-wide emergency. Below we describe each category, sector, and the potential services the different PV systems might provide. 1.1.0 Homes The vast majority of PV systems are residential. These systems tend to be approximately 3 kW of electrical capacity, making them appropriate for small loads such as cell phone charging, local emergency lighting, limited refrigeration, and/or operating medical equipment during power outages. The emergency power could be used exclusively in the home or made accessible to the City or the public. To protect the homeowner’s privacy, an externally mounted, lockable power distribution panel could be installed; additional safety provisions will be required to isolate the energized islanded system from the de-energized grid. 1.1.1 Businesses Private businesses have systems in the range of 10s-100s kW capacity range. Emergency power may allow a business to quickly resume its operations to provide goods and services to the community during disaster recovery. In some cases, with increased space and capacity compared to individual residences, commercial buildings could be used to shelter people and provide medical/life support and charge devices. 1.1.2 Nonprofits Nonprofit PV systems are similar in size to those of businesses. With their public mission, nonprofits organizations could be good locations to shelter people and power kitchen facilities, and many are already providing those services as part of their normal operations. 1.1.3 Municipal Facilities Municipally-owned facilities, such as schools, recreation centers, public health clinics, and libraries are well-positioned to provide emergency services such as shelter, communications, and health services. Additionally, municipal facilities could provide power to outdoor common areas (such as parks, parking lots, etc.) where people can gather, especially after earthquakes.


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1.2. San Francisco Case Study 1.2.0 Existing Infrastructure As of December 2016, San Francisco had 6,665 rooftop PV systems. Nearly all – 99% – of these systems are grid-connected with net metering. Over 95% of San Francisco PV systems are residential, with an average size of 3 kW. The 5% of systems that are non-residential average 51 kW. The majority of San Francisco PV systems were installed within the last three to four years, however inverter technology has improved so quickly that a significant percentage still have relatively old technology. Due to the work of the Smart Inverter Working Group new inverters installed in California are typically now “smart” inverters. These inverters have seven functions that the inverters must perform autonomously. These functions are related to the protection and control of the inverters and allow the inverters to ride through faults and operate in island mode with a battery. 1.2.1 Design Scenario An interesting feature of energy system resilience is that after a large earthquake, past experience has shown that the electric grid is likely to come back online significantly faster than the gas network. (Other types of disasters, such as a major storm, may have different relative speeds of utility recovery.) Figure 1 shows the time required for gas and electric systems to be restored based on analysis from the Lifelines Council under the San Francisco Office of Resilience and Recovery. The majority of electric systems are restored within the first week of operations, but gas systems can take months to come back online.

Figure 1: Time to return of service for SF utilities after a 7.9 magnitude earthquake.

Data credit: Lifelines Council1

1 http://sfgov.org/orr/lifelines-‐council 2 NEM Database, San Francisco 3 Ryan Wartena, GELI, 12/16/16 4 A real estate investment trust (REIT) is a company that owns, and in most cases operates, income-‐


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The design scenario used in the workshop assumed that the electric grid was down for one week and that the gas utility remained offline for months. The scenario assumed that sunlight was diminished due to stormy weather, smoke, or debris, which affected PV system output. During the week without the electric grid, there would be many injured people who required medical treatment. We assumed that relief supplies would arrive after the first week.

2. Technical Solutions for Retrofitting Solar Systems to Provide Resilience

2.0 Interactive System Disconnect The simplest and cheapest retrofit is to add an interactive system disconnect. Essentially this involves flipping a switch on a dedicated outlet when the grid is down, and the user can begin directly charging devices using the PV system. For a 1500 W capacity, this could be done for a few hundred dollars, which is why 450 have already been installed in San Francisco.2 However, this capacity is most applicable for charging small appliances, and can only be used while the sun is shining. Electricity storage would allow more flexibility in using the PV system, and would also improve the reliability and quality of the power provided.

2.1 Electric Storage Electric storage can be installed either in-front-of or behind-the-meter at a customer site. While applications for in-front-of-the-meter storage are being explored, in-front-of-the-meter storage currently is not typically an option for providing resilience to customer-sited PV systems due to difficulty in isolating sections of the grid from other utility customers in an emergency outage. Behind-the-meter solar + storage systems are typically owned and operated by the energy customer. 2.1.1 Stationary Batteries Rechargeable batteries can be added behind-the-meter to PV systems. This can be done either through coupling the battery to the PV on the DC side of the circuit with a single multimode inverter that replaces the existing inverter, or on the AC side of the circuit with an additional multimode inverter. Examples of these two options are shown in Figure 2. AC coupling is easier to install as a retrofit, but has a slightly lower efficiency than DC coupling because of conversion losses. Most likely, AC coupling will be used for near-term solutions, whereas DC coupling can be coordinated with major retrofits, such as end-of-life inverter replacements or lighting upgrades to LED, over a longer time frame. In the long term it may make sense to rewire loads to aggregate those that will be served in an emergency, and cluster these on their own circuit. In the interim, some loads will need to be turned off at the circuit breaker, switch, or at the device itself during a grid power outage to prevent overloading the solar + battery system. 2 NEM Database, San Francisco


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Figure 2: Schematics courtesy of Bill Brooks, Brooks Engineering

Batteries are typically expensive, costing thousands of dollars for a residential scale system and increasing in cost as scale increases for commercial systems. These costs may be recovered in part by using the batteries to store and dispatch energy during normal building operation 1) to shift when electricity is purchased from the utility, and 2) to limit solar export at times of low loads. The battery chemistry best suited for a particular application depends on how the batteries will be used. Lead-acid batteries are well-suited to systems designed solely for emergency services, which require infrequent cycles of deep discharge; lithium-ion batteries are better-suited for load shifting. 2.1.2. Electric Vehicles Plug-in electric vehicles (PEVs) have the potential to provide emergency backup power, playing the same role as stationary batteries while adding mobility. If bidirectional charging capability were to be added by manufacturers, PEVs could charge from either the grid, or from PV systems, and could be used as a source of emergency power during grid outages. To enable emergency backup power, PEVs and electric vehicle


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service equipment (EVSE, a.k.a. charging stations) must have bidirectional charging capability, where power flows 1) through the EVSE and to the PEV to charge the PEV's batteries; and can also flow 2) in the reverse direction to discharge the PEV's batteries. Emergency backup power can be provided when power flows in the reverse direction from the PEV's batteries through the EVSE to a building or grid point of interconnection. The PEVs and EVSE that are commercially available in the U.S. are not currently configured to provide this capability. The only current or soon-to-be commercially available option is a vehicle-to-home system only offered in Japan – the Nissan LEAF is configured for bidirectional charging. Honda may also soon offer a power exporter option. This is a costly option at the moment and manufacturers need to be convinced that there is a market for bidirectional backup power charging capability. Additionally, PEV battery warranties have to be reconceived to accommodate the possibility of exporting power. Finally, it is unclear whether the best use of these vehicles in a crisis would be to provide stationary power or emergency transport.

3. Barriers to Implementation

3.0 Motivation Retrofits for resilience may lack a sense of immediacy, particularly for private owners. The infrastructure may be perceived as “untested” and potentially interfering with baseline operations. Owners of facilities that already have diesel or gas generators may not be convinced by the added security of solar + storage in an emergency. However diesel shipments could be compromised in the case of an earthquake or other disaster. Nonprofits and businesses may see investing in solar + storage retrofits as encroachment on their overhead or profit, which might not be attractive to funders and stockholders. On the other hand some community-focused nonprofits and businesses may view resilience as a resource and significant benefit for the local community. Nonprofits, in particular, often have numerous stakeholders who need to be convinced in order to approve a system. Individual homeowners may have concerns about exposing their own residence to public use if the City were to encourage or require them to provide public access to their emergency power. Even owners who understand the value of solar retrofits may not have the time or the knowledge of how to proceed. They may be limited by physical space in their building, facility, or lot, or fear increased liability from allowing public interaction with their space during an emergency. All of these concerns have to be addressed, in addition to the obvious financial barriers.

3.1 Finances Retrofitting PV systems for emergency service inevitably costs money upfront and does not generate a clear return on investment. It is not obvious how to place a dollar value on resilience, particularly for a private entity on behalf of a public benefit. The beneficiaries are many and uncertain while the costs are concentrated on the building


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owner and concrete. Finances are even more complicated when the building is leased, potentially to multiple occupants. There may be uncertainty among consumers about eligibility for the Federal Investment Tax Credit when adding storage to existing PV systems. There are also fees associated with permitting and re-connecting a retrofitted solar system.

3.2 Regulatory Any PV system retrofit that allows off-grid or islanded operation requires a new interconnection application to the local electric utility. The circuit plan will be evaluated to make sure it doesn’t interfere with safety (e.g., no exporting power to downed power lines) or grid operation (e.g. won’t cause voltage problems).

Section 608 of the International Fire Code dictates rules for stationary storage battery systems. While this code is undergoing significant revisions, Table 608.1 dictates the current capacity thresholds over which compliance is required for different types of batteries. These thresholds are likely to apply to the larger, non-residential PV systems. The code provides additional thresholds that dictate when more safeguards against hazardous risks apply.

4. Strategies to Overcome Barriers

4.0 Motivational Strategies Outreach, education, and perhaps financial incentives may be needed for widespread uptake of solar retrofits for islandable operation and the addition of storage. The early adopters of this technology may be building owners who are already planning major renovations. Clients and donors to companies/nonprofits need to understand the value in these systems. Emergency response practice exercises could incorporate electrical outage drills to raise awareness of potential problems and solutions. Demonstration projects, most likely hosted at government or municipal buildings, will increase confidence that systems cost and function as expected without interfering with normal building operations; and will also help build the market of contractors familiar with the


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retrofit procedures. Finally, for building owners who allow community access to emergency power, privacy and liability concerns could potentially be handled by limiting emergency access to designated authorities, such as the fire department.

4.1 Financial Strategies 4.1.0 Valuing Resilience A significant part of community outreach to encourage these systems will have to include strategies to reveal the value of resilience. This may require a public awareness campaign about the cost of downed electricity in previous disasters, such as Hurricane Sandy. Getting building owners to evaluate costs they already spend on emergency services will provide an initial indicator of perceived value. Grocery stores, medical clinics, gas stations, and many other commercial buildings already pay for emergency services in the form of standby generators, fuel, and labor (approximately $200/kW-week for fuel).3 The value of resilient power systems could potentially be augmented if government or community entities were willing to pay private building owners for use of electricity during a disaster. 4.1.1 Raising Funds There are multiple strategies to help raise the funds required to cover the retrofits. The city could possibly help building owners obtain grants from foundations. Bulk purchasing agreements could be organized to install services for a set of buildings at a reduced rate. If resilient power systems were required in building codes, then the retrofits could be bond-financed and/or incorporated into a mortgage or real estate investment trust (REIT).4 Local or state tax credits could be issued for owners who take on these upgrades. These could potentially be funded by a surcharge on utilities for public disaster planning. New solar + storage installations may qualify for two currently available federal tax incentives, depending on the renewable energy percentage charging the battery: Modified Accelerated Cost Recovery System (MACRS), and investment tax credit (ITC). In a fact sheet on this topic, NREL assumed that adding storage to an existing renewable energy system would be eligible for the same benefit as a new system.5 A single taxpayer would need to own both the PV and the battery system, which would also need to be in close proximity. Another avenue for enabling resilient power systems is the Property-Assessed Clean Energy (PACE) programs, which helps home and business owners secure up to 100% financing for renewable energy, storage, and energy- and water-saving upgrades with payments through a special line item on their property tax bill.

3 Ryan Wartena, GELI, 12/16/16 4 A real estate investment trust (REIT) is a company that owns, and in most cases operates, income-‐producing real estate. REITs own many types of commercial real estate, ranging from office and apartment buildings to warehouses, hospitals, shopping centers, hotels and timberlands. (Source: https://en.wikipedia.org/wiki/Real_estate_investment_trust) 5 Emma Elgqvist, Kate Anderson, and Edward Settle, Federal Tax Incentives for Battery Storage Systems (Golden, CO: National Renewable Energy Laboratory, January 2017), NREL/FS-‐7A40-‐67558.


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4.1.2 Monetary Returns on Investment While there are differences in the optimal technology choice and control of batteries for demand side management and backup power, there are options that allow both. Energy service companies offer controls and systems to manage controllable building loads and batteries to maximize financial savings. This can be lucrative for commercial and industrial customers with larger utility bills and demand charges that motivate peak shaving. It is also possible that the government could pay building owners for the right to use their systems in an emergency. This could either occur in a single payment during a disaster, or as a periodic insurance policy.

4.2 Regulatory 4.2.0 Islanding Standard (IEEE 15476) The principal interconnection standard is not yet finalized, but was updated two years ago to allow islanding. Inverter and energy storage manufacturers, controls companies, and policy makers are working to build mass market adoption of key enabling technologies. 4.2.1 Standardized Permitting Permitting storage systems can be time, labor, and cost intensive. Assembling pre-approved utility interconnection packages could significantly reduce this burden. The building permitting process could also be streamlined for major renovations that include emergency power upgrades. 4.2.2 Other Mechanisms In addition to the financing mechanisms suggested above, governments could influence uptake of solar retrofits and islanding capability either by mandating some aspect of their inclusion (e.g., automatic transfer switches with inverters), or by expediting building permits for projects with community service attributes. Private organizations, such as the United States Green Building Council (USGBC) could update their distribution of LEED points to include public services in a disaster.

5. Summary In summary, the workshop brought together people with a wide spectrum of expertise in community organizing, PV and battery installation, technical analysis and research, policy, financing, codes, standards, and safety. Participants explored options to advance Solar + Storage for Resilience by enlisting the 6500-plus installed solar systems in San Francisco. The breakout groups identified barriers for each of the four building sectors - residential, business, nonprofit, and municipal. Participants developed a panoply of solutions and ideas to provide resilient power, summarized in above report, with details in Appendix B.

6 Standard for Interconnecting Distributed Resources with Electric Power Systems


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This workshop report has described the concept of using PV and storage systems for energy resilience following major power outages. This is critically important, especially in dense urban neighborhoods where energy services may be needed by many citizens. These PV systems may be available to directly charge loads or to augment electric storage systems. The workshop participants explored and discussed safety, technical retrofit issues, economics, and the use of electrical storage and other factors to promote resilient power systems. Significant work is needed to explore the most effective incentives to expand these systems and develop feasible technical retrofit pathways. Cost and benefit data are needed to demonstrate the value.


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APPENDIX A

San Francisco | Solar + Storage for Resilience Workshop - List of Participating Organizations


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Participating OrganizationsSan Francisco | LBNL Solar + Storage for Resilience Workshop

December 16, 2016

OrganizationARUPBrooks EngineeringCity Administrator's Office, City and County of San FranciscoDepartment of Emergency Management, City and County of San FranciscoDepartment of the Environment, City and County of San FranciscoCalifornia Energy CommissionCity of BerkeleyClean CoalitionCPowerGrowing Energy Labs, Inc. (GELI)International Brotherhood of Electrical Workers, San Leandro (IBEW)Integral Group, Inc.Johnson Controls International PLC - Distributed Energy Storage Lawrence Berkeley National LaboratoryLuminaltNRGPacific Gas and Electric Powertree Services, Inc.San Francisco Public Utility Commissionsonnen Inc.Strategen ConsultingTesla, Inc.U. S. Department of Energy


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APPENDIX B

Spurring Solar + Storage for Resilience - Detailed Notes


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Appendix B:

Spurring Solar + Storage for Resilience - Detailed Notes

This appendix discusses the ideas generated throughout the workshop and specifically in the breakout groups to boost solar + storage throughout San Francisco. The first subsection identifies both energy and non-energy benefits that may serve as incentives for building owners/residents. The second subsection discusses short-term and long-range strategies for retrofit opportunities. The next seven subsections discuss ideas that emerged throughout the workshop, clustered under rubrics such as community citizenship and public good, education and outreach, incentives, strategic and financing considerations, policies, and others. B.1 Benefits A number of benefits may accrue to building owners and residents as a result of installing PV and storage, including: energy independence, energy security, lower operating costs, hedging against energy price escalation, disaster resilience, greater energy reliability and controllability, backup power, cost savings, improved power quality, reduced greenhouse gas emissions, enhanced building value, adding resilience as a strategic competitive advantage, and home/business energy monitoring. Using PV with storage has the potential to stretch onsite fuel supplies needed to keep emergency services generators (police, fire, medical, and dispatch facilities) running during states of emergency. In some cases, the non-energy benefits may comprise the strongest incentives to building owners and residents. Value stacking may offset the capital costs of retrofitting or installing a new system. B.2 Short-term and long-term timeframes -- installing solar + storage Short-term strategies to strengthen resilience can leverage opportunities such as failure of existing components, and/or phasing in new components as original equipment approaches end of life. Failed inverters could be replaced by models which can operate in both islanded and grid-connected modes, and have the capacity to integrate a battery; and building owners and residents would realize the additional benefits of energy storage and security, and monitoring capability. (For example, some recent inverter models have the ability to power a local AC outlet during power outages, without batteries.) San Francisco could assemble a list of technologies that work in this way. Similarly, a portable battery/inverter package could be an attractive option for building owners and users; incentives may tip the decision. Workshop participants discussed planning the emergency use case and loads. To serve significant critical loads, an attractive short-term option may be to add storage, along with an AC-coupled second inverter. Also, participants recommended specialized training for safe system operations and maintenance.


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Long-term scenarios focused on DC-coupled systems. To maximize the length of time that emergency mode can be sustained, building owners could consider rewiring to isolate emergency circuits and reducing energy use through efficiency upgrades to significantly extend emergency operations mode. Savings from efficiency upgrades may help underwrite the retrofit costs. Long-term strategies could also include integration of bidirectional charging vehicles -- PEVs and EVSE. The availability of “portable batteries” could have significant positive impacts in the aftermath of a disaster. B.3 Community citizenship/public good One of the key challenges is to develop methods to better value energy resilience. Research from the NY Solar Smart Distributed Generation Hub summarizes some of these value streams: A one-day power outage for New York (NYC) is worth $1 billion in economic value.7 Local demonstrations of resilient technology systems and disaster preparedness training could provide needed groundwork for backup power systems. One key strategy that is likely to be needed is incentive programs to encourage retrofitting existing PV systems to provide public benefits during emergencies. B.4 Outreach and education It will be important to inform communities within San Francisco and those involved with maintaining critical city facilities about the potential benefits identified in this project. Demonstration projects can provide data to estimate non-resilience benefits detailed in section B1. Data could also be used to develop metrics for energy independence, energy security, greater reliability and controllability, improved power quality, and to quantify energy cost savings. If San Francisco rolls out wide-scale implementation of solar + storage, efforts should be made to learn from the process to improve the effectiveness of outreach and education. San Francisco officials may want to begin rollouts and demonstrations at targeted critical facilities and functions such as emergency shelters, grocery stores, urgent care clinics, gas stations, pharmacies, veterinary hospitals, radio stations, emergency dispatch offices, and others, to provide a baseline from which to develop strategies for other building owners/users. For example, a business case for resilience for businesses and nonprofits could include critical functions such as continuous operations, quicker recovery after a disaster, reduced emergency costs, and neighborhood involvement and participation in the aftermath. These ideas could be presented to nonprofit donors, users, and customers; as well as business developers, financers and funders, and client bases. With both businesses and multifamily residences, it will be important to develop incentives that split the value stream among stakeholders; outreach should encompass building owners, residents, and renters.

7 NY Solar Smart DG Hub Economics and Finance of Solar Plus Storage. http://www.cuny.edu/about/resources/sustainability/SmartDGHubEmergencyPower.html


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B.5 Technical There is a strong need for standard templates for retrofit designs and specifications tailored to different sized PV systems. Ideally these would be developed with the local electric utility. The local government and utility could also provide technical and procurement support. Building institutional capacity, knowledge, and expertise will raise the level at which staff can engage in these complex procurements. This might include pre-approved packages for retrofits that the local code officials support. Building control systems that can run the building in a lower power mode for many days at a time could greatly improve the emergency response outlook. Current power reduction strategies for demand response may only reduce loads for about four hours and reduce power by 10 or 20%. If there is an emergency it would be useful to be able to maintain a low energy operational mode - perhaps 50% of normal energy use, for several days. Currently California’s Title 24 includes demand response control systems. These requirements could be expanded to consider emergency control modes for lighting, HVAC, and other systems. B.6 Resilience strategies and policies Many of the functions enabled by resilience can be considered “public” benefits -- providing emergency power to enable communications, operating medical equipment, providing security lighting, etc. San Francisco may want to bridge the policy gap and create and structure incentives that will capture public resilience benefits. Resilience demonstration projects could instill familiarity, knowledge, and trust in a wide range of stakeholders -- residents, renters, building owners, different business-type owners, community-scale aggregators, solar developers and financers, building department and code officials, first responders, Pacific Gas and Electric (PG&E), San Francisco Public Utilities Commission, and the California Public Utilities Commission (CPUC). San Francisco may want to recruit for demonstration site partners; for example, the foundation community may lead demonstrations and serve as a model for the nonprofit sector. High visibility grants to undertake these demonstrations could snowball public visibility and adoption. San Francisco could target new construction and major renovations in the planning phase, where marginal costs for resilience planning will be lowest. San Francisco could filter for the buildings that provide the most valuable services in an emergency. Conversely, San Francisco could also screen building stock to rule out poor candidates for resilience upgrades. Electing to provide emergency power for community use could require certain conditions on accessibility during emergency (e.g. key access via local fire department); there could also be provisions to mitigate the owner’s liability. Local response teams could augment public safety, for example protecting buildings providing community resilience from damage/looting. Electrical medical needs could receive priority designation.


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PEVs could play a key role in resilience planning. PEVs could be contracted to provide emergency power to sites or emergency transport during disasters; this revenue stream may help defray capital costs. During the workshop, a number of possible incentives were discussed:

1. Award LEED points (or other building standard) for providing resilience capabilities to the community

2. Include "Microgrid-ready” and “Solar-ready” in property listings 3. Provide financial incentives for resilient power retrofits under the City’s

GoSolarSF program. B.7 Financing strategies Workshop participants identified a number of strategies to finance the construction of retrofit and newly installed resilient power systems in buildings:

1. Grant funding, ideally 3rd party facilitated 2. Federal Emergency Management Agency (FEMA) grants 3. Public/private partnership, i.e. energy service/savings companies (ESCO) 4. 3rd party ownership, similar to power purchase agreements of solar installers;

(see service contracts in uninterruptible power supply (UPS) markets) 5. PACE financing.

Building owners may qualify for two federal tax incentives which could significantly offset capital costs for new solar + storage systems, or for adding storage to existing renewable energy systems. Depending on the renewable energy percentage charging the battery, Modified Accelerated Cost Recovery System (MACRS), and/or investment tax credit (ITC) may be applicable.8 San Francisco could add a deduction or credit to the city’s property or business tax codes for community-based resilient power retrofits. Alternatively, similar revisions could be made to the California or federal tax codes. If San Francisco requires resilience retrofits/installations, a number of funding options may open:

1. Solar and storage may be eligible for bonds 2. Initial purchase mortgage and refinancing can include resilience upgrades. 3. Incorporating "Microgrid-ready” and “Solar-ready” in real estate listings may

enhance property values. The cost of energy during an emergency is likely to be significantly higher than during normal operations; it is important to include this cost differential in the cost-benefit analysis evaluating whether to provide islanding capability and storage to existing PV systems. For example, energy managers for businesses, nonprofits, and muni facilities could include in their analysis the cost of installing a backup generator, labor for generator operations and maintenance, and fuel during emergencies. Commercial enterprises may also consider the opportunity cost of lost business resulting from power

8 Emma Elgqvist, Kate Anderson, and Edward Settle, Federal Tax Incentives for Battery Storage Systems (Golden, CO: National Renewable Energy Laboratory)


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outages. Capturing these more accurate emergency power costs during scenario assessment may point to islanding plus storage as the least cost option. B.8 Testing and public safety The development of open standards will ease integration. To this end, San Francisco may want to work with code-making bodies to develop the needed codes and standards. Stationary storage warrants special concern, and fire codes and safety designs could be accelerated (e.g., NYC new codes). Safety training will be critical for building owners, resilient power system users, and fire and emergency response personnel who need to understand proper design, operations and maintenance for batteries. B.9 Fast track procurement and permitting to rapidly expand resilient power systems As described previously, leveraging inverter replacement may be an early, low-cost opportunity to add new capabilities to existing PV systems -- to operate without the grid present, and to add storage. San Francisco could provide procurement technical assistance and support, for inverter replacement as well as adding storage systems. Template designs and specifications could be available to building owners considering retrofits and new installations. Similarly, building owners could sort pre-approved packages by footprint to identify potential candidates for outdoor battery installation. A well-defined, streamlined, expedited permitting process will speed the expansion of solar + storage within San Francisco.

lawrence berkeley national laboratory san francisco | solar + … · 2017-11-28 · lawrence...

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