Community Microgrid planning and design A resilient clean energy solution Hi Everyone, my name is Malini Kannan. I’m a program engineer with the Clean Coalition, and have been here for 2 years. Today I’ll be presenting a high-level overview of the steps involved in planning and designing a Community Microgrid as a resilient, clean energy solution. My supervisor Frank Wasko wanted to be here today, but was pulled away on other projects. However, if you have any questions or feedback for him, his contact information is included here. Malini Kannan Program Engineer 650-533-8039 mobile malini@clean-coalition.org Frank Wasko Managing Director 949-501-0967 mobile frank@clean-coalition.org 18 July 2019

Clean Coalition (nonprofit) mission To accelerate the transition to renewable energy and a modern grid through technical, policy, and project development expertise The Clean Coalition's mission is to accelerate the transition to renewable energy and a modern grid through technical, policy, and project development expertise We are a 501c3 nonprofit. 2

About the Clean Coalition A wealth of experience in microgrid planning and engineering Developing projects that provide unparalleled economic, environmental, and resilience benefits. Renewable energy modeling and design 15+ Community Microgrid feasibility assessments completed to date with clients including Stanford University, various Fortune 500 companies, and multinational independent power producers (IPPs); 2 California Energy Commission (CEC) grants; 1 Department of Energy (DoE) grant; 1 National Renewable Energy Lab (NREL) contract. Experience working with utilities Investor-owned utilities (IOUs): PG&E, SCE, SDG&E, PSEG Long Island; Municipal utilities: CPAU, LADWP, SMUD; Current active projects with PG&E, SDG&E, SCE, CPAU. The Clean Coalition is a nonprofit organization based in Menlo Park, California with a wealth of experience in renewable energy policy, and microgrid planning and engineering. We focus on developing microgrid projects that deliver economic, environmental, and resilience benefits. To date, our portfolio consists of renewable energy modeling and design work including: 15 Community Microgrid feasibility assessments with groups like Stanford University, various Fortune 500 companies, and multi-national independent power producers (IPPs) We've worked on 2 California Energy Commission grant-funded projects, one Department of Energy grant, and a contract with the National Renewable Energy Lab. In addition, we have extensive experience working with utility companies, including PG&E and municipal utilities.

Community Microgrid planning and design presentation outline Current situation Lack of resilience. Traditional grid and microgrids Microgrid vs. Community Microgrid; Benefits and components. Community Microgrid planning and design methodology. This is our agenda for this afternoon I'll start by giving some background on the current lack of resilience in certain parts of the county, and explain the distinction between the traditional grid, microgrids, and Community Microgrids. I will briefly discuss regulatory challenges and solutions to implementing Community Microgrids, and a provide the framework for a pathway forward. I'll then take a deep dive into the various elements required for community microgrid design, and the methodology used.

Current situation: Public Safety Power Shutoffs (PSPS) outages Negative impact: Critical facilities, businesses, and residents lose power during planned shutdowns and cannot provide services. Microgrids can provide a solution to keep power on; however, local hazards (e.g. local fire threats) need to be considered to be considered in the design process. In order to cope with increased wildfire risk in their service territory, PG&E has implemented a public safety power shutoff (PSPS) program, which affects some communities in the North Bay region. The wildfires of 2017 and 2018 were devastating. Unfortunately, they are not anomalies. It is important for us to recognize this unfortunate reality, and adapt to it by changing the way we design, build, and power our communities. The way the PSPS works: During high wind and low humidity conditions, PG&E will shut down certain at-risk power lines. Senate Bill 901 opened a proceeding at the California Public Utilities Commission that will investigate solutions to mitigate wildfire risk, including power shutdowns to avoid sparking wildfires in high-risk conditions. Based on recent community workshops with PG&E, there were multiple PSPS events planned in 2018, although only one was executed. Going forward, outages are expected to be more frequent, with outages lasting up to 3-5 days. The major impact of these long-duration power outages is that critical facilities, business, and residents lose power and cannot provide or receive critical services. Source: https://www.pge.com/en_US/safety/emergency-preparedness/natural-disaster/wildfires/public-safety-power-shutoff-notifications.page

Current situation: Lack of resilience Former California Governor Jerry Brown said wildfires likely represent the “New Abnormal” and that we must adapt to it by changing the way we design, build, and power our communities. The map here shows the San Francisco Bay Area and counties north of that, including Marin, Sonoma, and Napa counties. Red represents extreme fire threat zones Gold represents elevated fire threat zones California utilities may shut off power through and to these areas as part of the PSPS program. Negative impact: Critical facilities, businesses, and residents lose power during planned shutdowns and cannot provide services. Microgrids may provide a solution that offers emergency backup power and resilience to these areas, however local hazards must be considered. For example, it may not make sense to site a microgrid that uses over-head distribution wires in one of these red or yellow zones. For example, during a PSPS, energizing overhead distribution lines within a fire-risk zone with a Community Microgrid may be defeating the purpose of the PSPS, which is to mitigate fire risk. However, if a site is affected by the PSPS, but outside the threat zone a Community Microgrid could provide a viable solution to power-shutoffs. For example a community might be served by a transmission line that is in the red zone, but the community itself might not be at risk for fire, meaning that local generation sources, could be used. PG&E has done the simple version of this, which is to install mobile diesel generators, however we propose a solution with local, renewable DER. Source: https://ia.cpuc.ca.gov/firemap/ CPUC fire threat map Source: https://ia.cpuc.ca.gov/firemap/

$1B+ weather events in U.S. Jan – Sept 2017 Current situation: $1B+ weather events in U.S. Jan – Sept 2017 Source: National Oceanic and Atmospheric Administration These catastrophic events are not isolated to the North Bay. Extreme weather events are occurring all over the Nation and globally. This graphic was developed by National Oceanic and Atmospheric Administration, and it represents the cost of these extreme events in the USA. Extreme weather events are occurring more frequently: From January through September 2017, the U.S. experienced 16 weather- and climate-related events that cost $1B or more, for a record-breaking total of $300B (National Oceanic and Atmospheric Administration) Our centralized energy infrastructure is highly vulnerable to extreme weather, and is the leading cause of power outages in the U.S. today 7

What is power system resilience? Resilience: The ability to keep critical loads online indefinitely in the face of extreme or damaging conditions This is Clean Coalition’s definition of resilience; Focused on reducing outage duration, cost, and impact on critical services; Timescale: hours or days. Power quality: Issues with harmonics, power factor, etc.; related to voltage, frequency, and waveform of electricity on the grid Timescale: micro-seconds. Reliability: Measured after 5 minutes of grid outage Timescale: minutes. So we can see how extreme weather is a contributing factor to lack of resilience in our current energy system. But what is power system resilience? Resilience is not something that is measured in today’s energy industry. There are metrics for power quality, which measures issues related to harmonics, power factor, etc. that are related to grid voltage, frequency, and waveform. I like to think of these metrics happening on the timescale of microseconds to seconds. There are metrics for Reliability, which measure the frequency and duration of outages. Here the timescale is minutes, and the common metrics measured by electric utilities are “SAIDI and SAIFI” This is definitely a start, however "major events” are excluded from SAIDI and SAIFI, and I’m not clear on how extreme weather and PSPS factor into those numbers. So neither power quality or reliability measure resilience, which is the ability to withstand and recover quickly from events. Clean Coalition defines resilience as the ability to keep critical loads online indefinitely in extreme conditions. Portions of a resilient grid may go down for some time in an outage, but prioritized facilities or service for critical customers like hospitals, water and sanitation systems, first responders, communications towers, and food storage can remain energized in a resilient system. For example, there could be a brittle grid, or a non-resilient, but it could have high reliability because there are no external factors that affect it. On the other hand there could be a strong grid, a resilient grid, where there is a reason for grid outages to happen. Metrics for resilience aren’t in place, and are harder to develop because there aren’t good statistics. If you could measure grid perturbations, then you could compare the length and duration of outage for a non-resilient grid versus and resilient grid. If you do have an event, how quickly will that area have service restored? If there is a major voltage fluctuation, or something going on electrically with the grid, does it cause an outage? Is there protection equipment on the grid to prevent this from spreading to other customers? Can either cut off that section, or have protection. SAIDI (system average interruption duration index) minutes or hours SAIFI (system average interruption frequency index) number of outages over 5 minutes long

Long-term vision: Community Microgrids Long-term vision: Develop Community Microgrids to serve areas that currently lack reliable power, or that are at risk for frequent power shutoffs. A microgrid provides a solution that allows the local loads to be served by local energy sources; this is especially critical when the grid is shutdown. Clean Coalition’s long-term vision for resilient communities it to establish Community Microgrids that serve areas that lack reliable, resilient power. This includes critical facilities, but also municipal buildings, commercial sites, and residences. The graphic shows that during a grid outage, the switch can be turned off, and the Community Microgrid can be electrically disconnected from the grid. When the grid goes down — whether due to a public safety power shutoff or other cause — the local resources — solar, batteries, wind, electric vehicles, etc. — can be coordinated and controlled to supply all of the critical loads.

Facility microgrids focus on single customers The equipment — including solar, batteries, etc. — is located on a single customer site. Many commercial and industrial facilities can realize cost savings from on-site microgrids, and have the ability to disconnect from the grid (also known as islanding) during grid outages. However, the benefits of these microgrids are typically limited to that customer or business. Source: Oncor Electric Delivery Company 10

Community Microgrids can serve up to thousands of customers “PROSUMERS” For this reason, the long-term vision for resilient communities should include Community Microgrids. Community Microgrids can span the entire distribution grid area served by a substation, and serve the local load with local resources. Local loads can include homes, businesses, and critical facilities. Local resources can include rooftop solar, battery energy storage, and larger resources like geothermal, wind, etc. While it's possible to utilize diesel generators and natural gas generators or fuel cells, renewable resources provide the greatest level of resilience and environmental benefits, with lower operational costs than fossil-fuel resources. CRITICAL FACILITY MICROGRIDS “PROSUMERS” Source: Oncor Electric Delivery Company 11

Community Microgrid defined A modern approach for designing and operating the electric grid, stacked with local renewables and staged for resilience. Can “island” from the grid: A coordinated local grid area that can separate from the main grid and operate independently. Components: Solar PV and other renewable energy, energy storage, demand response, and monitoring, communications, & control. Clean local energy: Community Microgrids facilitate optimal deployment of distributed energy resources (DER). Resilient: Ongoing, renewables-driven backup power for critical and prioritized loads, and eventually all community energy needs. Replicable: A solution that can be readily extended and replicated throughout any utility service territory. Image: Berkeley Labs Lowers customer and system costs: Reduces the most expensive peak periods and associated energy and infrastructure costs. Increases local investments: Increases critical economic investment in local communities, enabling targeted environmental justice considerations. Improves grid performance: Replaces onsite and centralized fossil fuel generators and transmission infrastructure; reduces the complexities and costs of centralized balancing. Delivers resilience and security: Provides ongoing power to critical and priority loads in communities and can withstand multiple disaster and/or cyberattack scenarios. Creates a replicable and scalable model: Covers entire substation areas; can be scaled and deployed in any community.

Community Microgrid benefits Reliability and power continuity. Resilience and safety. Local, renewable energy Greenhouse gas reductions; Local control of energy; For electric vehicles and charging infrastructure; Reduced transmission losses. Local jobs in engineering, construction, and maintenance. More participation enables by a network of “prosumers” who share the use, generation, and revenue of and from energy. Energy security and national security.

Community Microgrid planning and design methodology Phase 1: Feasibility assessment Stakeholder alignment and goal setting: Design requirements and constraints Perform Solar Siting Survey (SSS); Shortlist sites for basic technical and economic analysis; Gather basic site details including load data, and perform a technical and economic analysis: Aim for 70% accurate cost estimates. Phase 2: Planning and engineering Detailed technical and economic analysis; Develop conceptual and functional design; Engage engineering, procurement, and construction firm (EPC) to develop key engineering documents needed for utility buy-in (single-line diagram). Phase 3: Develop request for proposals (RFP). The methodology covers the feasibility assessment (solar siting survey, early stage shortlisting of sites, basic technical and economic analysis) Outcomes include a presentation with preliminary findings, and ongoing meetings Planning and engineering: deep dive feasibility assessment where we gather all site details to develop more accurate cost estimates. Meetings will include on-site assessments, finance meeting, design reviews, and a meeting with the utility Outcomes include draft and final design and economics presentations with: Electric load analysis, utility bill analysis, system sizing analysis, and economics overview Electrical contractor will provide: interconnection summary, single-line diagrams, and civil site drawings Develop RFP: Develop RFP specifications and work with the client to integrate it into their boilerplate RFP language and host a competitive bid process.

Phase 1: Community Microgrid stakeholder alignment To make a Community Microgrid a reality requires participation and collaboration from a variety of stakeholders The stakeholders listed here are project specific, but there are also industry specific stakeholders that should be involved- e.g. labor unions. The Clean Coalition has worked across the state and nationally to design and develop Community Microgrids from feasibility assessment through the RFP process. Utility participation is required to ensure that the resulting system is cost-effective and safe. Municipalities can hold key leadership roles in advocating for safer, more reliable energy systems for their communities. Property owners, residents, and local businesses provide key feedback on critical facilities. For example, while hospitals and fire departments are obvious critical facilities, there are less obvious critical facilities that could greatly benefit from emergency backup power, such as senior centers, gas stations, and street lights. Financiers and solutions providers help take designs and plans and make them a reality. Depending on the scale of the project, a workshop with all the stakeholders can be a good way to kick off the process.

Phase 1: Set goals, requirements and constraints Goal setting: develop SMART goals. What are the local requirements and constraints for the design? What does the community want their microgrid to do? What is the long-term vision, and the short-and mid-term plan? Important to keep in mind that a microgrid is not a silver bullet that can solve all issues, but it does mitigate outage risk. What are the local hazards, and how much of a risk do they pose? Design considerations: Have any sites undergone energy efficiency improvements yet? Is there any expected load growth? Use local knowledge to kick-start design process- are there good candidate facilities that provide critical services? SMART goals: Specific, Measurable, Achievable, Realistic, Timely

Phase 1: Solar Siting Survey (SSS) for Montecito To help illustrate the steps involved in Phase 1, the Clean Coalition is working on the Montecito Community Microgrid to achieve resilience in the Goleta Load Pocket in the Santa Barbara area. There are a lot of similarities between Montecito and the North Bay region we're in now. Both communities are threatened by natural disasters, and have an energy system that lacks redundancy. In Montecito, which is a small community, we’ve identified 30 MWac (10 kWac min) San Diego: 500 MWac (1 MWac min) Alameda County: 650 MWac (1 MWac min) PAEC: almost 70 MW (100 kWac min) in portions of San Mateo County (RWC - MP)

Phase 1: Hot Springs Feeder via Santa Barbara Substation As part of developing the SSS, we also evaluate the siting potential compared to the local hosting capacity. If we need to trigger grid upgrades, the projects can become much more expensive, so this is an essential cost-reducing step.

Phase 1: Critical facilities along Hot Springs Feeder Identify critical facility clusters Do those facilities have some amount of solar siting potential, and space for energy storage batteries? People familiar with the site can be a huge asset here, to identify potential shading issues Information can be charted on GoogleEarthPro, or by hand on printed maps Track "leads" in a spreadsheet

Phase 1: Montecito Upper Village block diagram Diagram elements Autonomously controllable microgrid relay/switch (open, closed) Emergency response cluster Tier 2 & 3 loads Commercial cluster Commercial cluster Tier 2 & 3 loads Southern Portion Emergency sheltering cluster Southern Portion Emergency sheltering cluster Identify candidate critical facilities such as critical public services, medical care, and emergency shelters. This is a proposed solution that is under discussion with Southern California Edison, the local utility for this project. The interconnection process is still pending rule 21 review and diagrams may change. There are similar project that utilize distribution lines to connect multiple sites, however they are in the pilot-phase, and are not a solution that’s available to everyone yet. Hot Springs Feeder (16 kV) Santa Barbara Substation Transmission Coast Village Community Microgrid Interconnection process is pending Rule 21 review. Diagrams may change.

Phase 1: Gather load data: Utility bills Gathering load data is a key step in performing a feasibility assessment. It’s useful to have 1 year of utility bills, and one year of 15-minute interval data. Explain important parts of the bill and totals Some notes to keep in mind- ask if your site has any new loads expected to come online soon, also make note if they are on a new rate.

Phase 1: Gather load data: 15-minute interval data PG&E Share My Data Program, which used to be the Green Button program for data sharing (direct customer download) UtilityAPI also offers an easy way to authorize sharing of utility data While the vast majority of meters are smart meters, not all are, and not all smart meters are set to automatically collect data: We’re seen sites with 3 meters, and only 2 collect interval data With schools and some municipal clients, need to get hard-copy paperwork signed, cannot be done totally online. Collecting this data can take a good amount of time, depending on the client. There’s a PG&E workshop next week about Rates and Tariffs, and I’m excited to check it out.

Phase 1: Basic technical and economic analysis Key inputs: normal load profile, critical load profile, and rate tariff. Goal: Determine optimal system sizing of PV, energy storage, and other DER for both normal grid-parallel operations and emergency grid-island operations. Estimating critical loads Tier 1 = Critical (10%) — crucial and life-sustaining loads. Tier 1 loads can be critical facilities like fire stations, water systems and communications infrastructure; Tier 2 = Priority (15%) — important but not necessary; Tier 3 = Discretionary (75%) — the remainder of the total load; These estimates will not work for all facilities (e.g. hospitals). The key inputs to the analysis in Phase 1 is the load profile, critical load profile and rate tariffs. That is because these provide the load that must be served during normal operations and emergency operations, and indicate the cost for the current solution (grid-powered electricity) The goal is to determine optimal system sizing of PV, energy storage, and other DER for both normal grid-parallel operations and emergency grid-island operations At this stage, we use some basic estimates to develop critical load profiles Tier 1 = Critical (10%) — crucial to keep operational during a grid outage (for some facilities even life-sustaining loads). Tier 1 loads can be critical facilities like fire and police stations, and water and communications infrastructure. Tier 2 = Priority (15%) — important but not necessary to keep operational during an outage. Tier 3 = Discretionary (75%) — the remainder of the total load. It’s important to remember that these estimates will not work for all facility types. E.g. hospitals are subject to regulations that make load-shedding very challenging. There are also seasonal variations to consider, but at this early stage of design, we use these numbers to produce the first iteration. I’ll dive into the tools used in the next section

Phase 1: Montecito Upper Village emergency response facilities Determine ballpark costs and benefits: Perform basic load analysis, solar sizing, and battery sizing, and develop cost estimates and system configurations Utilize easy-to-use software with quick outputs to perform many design iterations at this phase Use standard assumptions to streamline feasibility assessment We don't typically develop these fancy graphics at this stage; however, they are included here to illustrate the outcomes of Phase I. Questions at this stage? Interconnection process is pending Rule 21 review. Diagrams may change.

Community Microgrid planning and design methodology Phase 1: Feasibility assessment Stakeholder alignment and goal setting: Design requirements and constraints Perform Solar Siting Survey (SSS); Shortlist sites for basic technical and economic analysis; Gather basic site details including load data, and perform a technical and economic analysis. Aim for 70% accurate cost estimates Phase 2: Planning and engineering Detailed technical and economic analysis; Develop conceptual and functional design; Engage engineering, procurement, and construction firm (EPC) to develop key engineering documents needed for utility buy-in (single-line diagram). Phase 3: Develop request for proposals (RFP). The methodology covers the feasibility assessment (solar siting survey, early stage shortlisting of sites, basic technical and economic analysis) Outcomes include a presentation with preliminary findings, and ongoing meetings Planning and engineering: deep dive feasibility assessment where we gather all site details to develop more accurate cost estimates. Meetings will include on-site assessments, finance meeting, design reviews, and a meeting with the utility Outcomes include draft and final design and economics presentations with: Electric load analysis, utility bill analysis, system sizing analysis, and economics overview Electrical contractor will provide: interconnection summary, single-line diagrams, and civil site drawings Develop RFP: Develop RFP specifications and work with the client to integrate it into their boilerplate RFP language and host a competitive bid process.

Redwood City Community Microgrid conceptual diagram The conceptual diagram illustrates which DER assets a site will deploy. The orange sites are candidates for behind the meter microgrids, while the green sites are candidates for Community Microgrids involving more than one utility meter. The sites shown here are in various stages of development. As I explain Phase 2 of the Community Microgrid planning and design methodology, I’ll be using the the Hoover Cluster as an example. The Hoover Cluster consists of 3 sites owned by the same entity and includes a public school, Boys and Girls Club, and a public park.

San Mateo County Corporate Yard (SMC Yard) Deployment summary Site name Meters or buildings Critical Loads NEM solar [kW AC] FIT solar [kW AC] Total solar [kW AC] Battery [kW] Battery [kWh] EVCI (Level 2) Stanford Redwood City Phase 1 P1, B1-B4 Campus emergency response 886 251 2,100 52 Hoover Cluster Hoover School Shelter & food service 73 203 276 29 150 20 Boys & Girls Club 11 90 101 10 Hoover Park Equipment staging Redwood City Corporate Yard Road and public facility maintenance and repair 136 352 488 58 360 *4 San Mateo County Corporate Yard (SMC Yard) SMC Yard Meter 1 65 240 SMC Yard Meter 2 33 121 154 SMC Yard Meter 3 79 Sobrato Broadway Plaza Sobrato Broadway Plaza (multiple meters) Low-income housing 1,197 TBD Sobrato CVS Pharmacy & grocery 83 New Deployments TOTAL 1,204 2,125 3,329 396 2,850 82 This table shows the deployment summary for DER in the Redwood City Community Microgrid. DER in the design include solar PV, batteries and EVCI There are three options for deploying solar PV; the first is that which would be eligible under a NEM interconnection NEM: net energy metering The second option is for interconnecting solar under a Feed-In-Tariff; this FIT doesn’t exist yet, but we’re working with the local CCA, Peninsula Clean Energy to serve as an offtaker for the solar PV. The third option is to deploy all solar, under the two interconnections NEM and FIT. With net metering, only 1.2 MW can be deployed. With a new Feed-In Tariff (FIT) program, an additional 2.1 MW of local, renewable generation could be deployed. We are working with the local community choice aggregator (CCA) to serve as an offtaker for the FIT solar.

Phase 2: Planning and engineering technical approach Step 1: Detailed site info and site walk. Step 2: Load shedding and operational design. Step 3: PV system sizing. Step 4: Grid-parallel optimization. Step 5: Grid-island optimization. Develop system sizing recommendation, cost estimates, conceptual diagram, and SLD block diagram. Work with EPC to develop SLD and basic civil CAD drawing.

Obtain site as-built drawings Conduct site walk Phase 2: Planning and engineering Step 1: Detailed site info and site walk Obtain site as-built drawings Architectural, electrical, structural Conduct site walk Validate: Solar siting potential and feasibility; Energy storage and electric vehicle (EV) charging locations; Details of existing electrical infrastructure (meters, AC bus sizing, etc.). Assess critical load: In Phase 1, Tier 1 critical load was estimated to be 10% of normal load; In Phase 2, we develop a ground-up energy budget that accounts for site- specific and emergency operations. This is more accurate than a load percentage; The activity following this presentation will explore this concept more.

Phase 2: Planning and engineering Step 2: Load shedding Utility-scale definition: rolling blackouts. Building or community-scale definition: shedding circuits so the load matches the available generation capacity. What loads are non-critical?

Phase 2: Planning and engineering Step 2: Operational design Automatic transfer switches enable load shedding with an emergency load panel. Other switch types can provide more functionality.

Phase 2: Planning and engineering Step 3: PV system sizing Size and model multiple PV systems using PVWatts from NREL: 1st system: Full-scale PV deployment. Use all feasible on-site rooftops, parking lots, and open spaces as defined in the Solar Siting Survey and site walk; 2nd system: Net-metered PV system. Determine system size based on annual utility bills; 3rd system: Net-metered PV system with load growth. If the site is a candidate for load growth (e.g., EV charging), combine the existing load profile with the project load profile of additional EV chargers. We need to design PV systems for grid-parallel operations, because this is where there is opportunity for cost-savings and/ or revenue generation This is what will help pay for the microgrid. Because there are different site-specific conditions, it’s worthwhile to model various systems, and see which offer the best internal rate of return (IRR). These are three options of systems to model, that we have found make sense for our clients (municipal, university, campuses, etc.) but there might be other systems that should be explored for other facility types.

Phase 2: Planning and engineering Step 4: Grid-connected optimization with ESyst Used Geli's ESyst tool to determine the optimum energy storage size for a grid-connected system that takes advantage of peak shaving and demand charge management. Example: The figure below shows the projected savings for one of the solutions for RWC Yard: 150 kW of PV, and 58kW 240kWh of energy storage. Again we are looking at an example from the Redwood City Community Microgrid- this is for the RWC Corporation Yard. Baseline bill is 54% energy charge, 44% demand charge, and 3% fixed charges. With solar only, there is a total bill savings of 41% With solar+ storage, there is a total bill savings of 71%. The savings will be paid partially to the 3rd-party system owner, and will be partially realized as monthly operational savings for RWC Yard.

Phase 2: Planning and engineering Step 5: Off-grid optimization with HomerPRO To properly size the system for island mode and use of the Community Microgrid during emergency operations, the critical load profile was input into HomerPRO. HomerPRO is a microgrid optimization tool. Simulation inputs: Critical load profile; Total on-site solar potential; Assumptions: uptime required: 100%; Cost assumptions and incentives. Simulation outputs: Optimal energy storage system sizing, based on optimization of net present cost of the system. Cost information is given in the backup slides

Phase 2: Planning and engineering Cost assumptions and incentives PV CapEx: $1,750/kW 30% Investment Tax Credit (ITC) is applied to EPC ground-mount price of $2.50/W; O&M costs: $10/kW/year; Replacement- $2,000/kWh (reflects end of ITC program and 20% reduction in module price). Battery CapEx: $136.80/kWh 30% ITC is applied and SGIP Phase II applied; O&M costs: $5/kWh/year; Replacement- $205/kWh (replacement occurs when battery has degraded by 30%). Converter CapEx: $569.30/kW DC-coupled system- PV and battery share a converter; 30% Federal ITC is applied; O&M costs: included in PV & battery O&M costs; Replacement- $850/kW (every 15-years). EPC PV price is based on a 100 MWdc/70MWac ground-mount system. To qualify for the 30% FITC on the battery, we need to ensure that the battery is charged from the solar PV at least 75% of the time This requires some special revenue-grade metering, and needs to be incorporated into the controller logic. All cost assumptions can be seen in the individual configuration report If the site has an existing diesel generator, it’s possible to include it in the microgrid. For modeling purposes, you may or may not want to include the diesel CapEx for the following reasons: Existing diesel generators and fuel storage tanks may be old and fully or almost fully depreciated Solar+storage might provide a way to obviate diesel generator replacements going forward

Phase 2: Planning and engineering Hoover Cluster conceptual diagram 126 kW Solar Carport 77 kW Solar Carport Hoover School Main Transformer 30 kW/ 150 kWh Battery M 83 kW Solar Carport Not drawn to scale 10 L2 EVCI ports 73 kW Rooftop Solar Tie line under review with permitting department Proposed trenching path 18 kW Rooftop Solar Hoover Park Meter Main BGCP Meter Main BGCP Main Transformer Hoover School Meter Main Proposed overhead conduit path Interconnection process is pending Rule 21 review. Diagrams may change.

Phase 2: Planning and engineering Hoover Cluster detailed map Interconnection process is pending Rule 21 review. Diagrams may change.

Phase 2: Planning and engineering Hoover Cluster conceptual single-line diagram To tility To Utility To Utility To Utility (N) UTILITY XFMR TBD (N) UTILITY XFMR TBD (N) UTILITY XFMR TBD (N) UTILITY XFMR TBD NOTE: Utility to size all new XFMRs Existing Meter New Meter Existing Meter New Meter ATS ATS ATS ATS Hoover School (N) 2400 A Bus Redwood City Boys & Girls Club (N) 1400 A Bus ATS ATS (N) 250 A Bus (N) 150 A Bus Solar PV 203 kW 200 A Li-Ion Battery 30 kW/ 150 kWh 35 A Solar PV 90 kW 92 A Solar PV 11 kW 12 A 10 L2 EV charging ports 300 A NOTE: Solar will be interconnected under a FIT. Being presented to outline the concept During normal operations, the FIT solar exports to the grid, and is sold to a pre- determine off-taker, most likely a CCA. Also during normal operations, the NEM solar exports to the grid. During a grid outage, both FIT and NEM systems are islanded from the grid, and the FIT solar can be used as another DER on the microgrid. The design is under development, and the interconnection process is pending Rule 21 review. Diagrams may change. From this stage, wed’ need to work with an EPC or a professional engineer to develop true single line diagrams, and use those to secure utility buy-in NOTE: Solar will be interconnected under a FIT. Solar PV 73 kW 80 A 20 L2 EV charging ports 600 A NOTE: Solar will be interconnected under PG&E's NEM2. Legend Transformer Electric utility meter ATS Automatic Transfer Switch Power line Communication line NOTE: Solar will be interconnected under PG&E's NEM2. Interconnection process is pending Rule 21 review. Diagrams may change.

Community Microgrid synergies Bundling DER deployments can improve bankability. Focusing on critical facilities and critical loads only minimizes the cost of resilience. Designing Community Microgrids for sites that have already implemented energy efficiency measures can save money. Integrating a battery into a site with EV charging can reduce demand charges and reduce the impact of high- power charging on the grid. Bundling DER deployments can improve bankability Implementing Community Microgrids at critical facilities and for critical loads only ensures that communities can receive resilience benefits (continued operation and recovery after a natural disaster or emergency), while the cost for this resilience is minimized. Critical facilities include important public and private services such as city public works departments to clear roads after a storm, hospitals and clinics to continue caring for the ill or injured, and community shelters and emergency response staging areas.

Community Microgrid planning and design methodology Phase 1: Feasibility assessment Stakeholder alignment and goal setting: Design requirements and constraints. Perform Solar Siting Survey (SSS); Shortlist sites for basic technical and economic analysis; Gather basic site details including load data, and perform a technical and economic analysis: Aim for 70% accurate cost estimates. Phase 2: Planning and engineering Detailed technical and economic analysis; Develop conceptual and functional design; Engage engineering, procurement, and construction firm (EPC) to develop key engineering documents needed for utility buy-in (single-line diagram). Phase 3: Develop request for proposals (RFP). The methodology covers the feasibility assessment (solar siting survey, early stage shortlisting of sites, basic technical and economic analysis) Outcomes include a presentation with preliminary findings, and ongoing meetings Planning and engineering: deep dive feasibility assessment where we gather all site details to develop more accurate cost estimates. Meetings will include on-site assessments, finance meeting, design reviews, and a meeting with the utility Outcomes include draft and final design and economics presentations with: Electric load analysis, utility bill analysis, system sizing analysis, and economics overview Electrical contractor will provide: interconnection summary, single-line diagrams, and civil site drawings Develop RFP: Develop RFP specifications and work with the client to integrate it into their boilerplate RFP language and host a competitive bid process.

Phase 3: Develop request for proposals (RFP) Develop an RFP, collect responses, and select winning proposal.

Steps to establish a microgrid Identify project team: EPC, financier, vendors, utility engineers, etc. Develop finance-ready collateral. Secure financing with a letter of intent (LOI), a signed power purchase agreement (PPA), or an energy services agreement (ESA). Submit interconnection application. Develop permit-ready drawings and secure permits. Procure equipment (solar, batteries, etc.). Construction and commissioning. Measurement and verification of system operation and cost savings. Post RFP, there are a number of steps involved Throughout this process, there must be consistent communication with and buy-in from the stakeholders. Stakeholders include city staff, elected officials, site owners, PG&E, and the design team.

Permitting and interconnection Permitting: Redwood City Planning and Permitting Departments do not anticipate any roadblocks with permitting photovoltaics, lithium battery energy storage, or electric vehicle chargers. Interconnection: Proposed generating assets (solar and energy storage) can be interconnected within PG&E service territory under the NEM2 or NEM Multiple tariffs. A few quick notes on permitting and interconnection

Thank you! Any questions? Implementing Community Microgrids at critical facilities and for critical loads only ensures that communities can receive resilience benefits (continued operation and recovery after a natural disaster or emergency), while the cost for this resilience is minimized. Critical facilities include important public and private services such as city public works departments to clear roads after a storm, hospitals and clinics to continue caring for the ill or injured, and community shelters and emergency response staging areas. Malini Kannan Programs Engineer 650-533-8039 mobile malini@clean-coalition.org Frank Wasko Managing Director 949-501-0967 mobile frank@clean-coalition.org

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Pathway to Community Microgrids Pre-installed interconnection hub (PIH) microgrid (PG&E only) Behind-the-meter microgrids at critical facilities Timeline for deployment Long-term 5-10 years Mid-term 3-5 years Near-term 1-3 years Scope and scale Entire substation grid area Municipal buildings, businesses, and residences Neighborhood Priority sections of the distribution grid Determined by stakeholders and PG&E Single building Critical facilities are key target sites Businesses and residences can also choose to deploy Loads to be served All loads Critical and priority loads All loads within the priority sections of the distribution grid Design can accommodate critical, priority, and noncritical loads Renewable energy demand* TBD based on the loads of the PIH area TBD based on desired loads This table summarizes the different configurations and scales of microgrids that could solve resilience challenges. Each column describes the high-level qualities of each type of microgrid. For a Community Microgrid: Existing diesel generators can be used to supplement the backup power provided by solar and energy storage. *Renewable energy supply can be augmented with existing diesel generators

Microgrids: Policy overview Behind-the-meter (BTM) microgrids: Policies to enable islanding and operation behind the meter exist. These systems are being deployed now. Applies to buildings and campuses with a single utility meter. DER interconnection: Net energy metering (NEM) or non-exporting backup power Key requirement: Automatic transfer switch (ATS) Major constraint: Policies allow microgrids, but utility rate tariffs do not necessarily incent developing microgrids for all customers. Microgrids using the public grid (e.g., Community Microgrids) face the same policy barriers as DER: How do DER get compensated for grid services? How do we manage open access to utility wires? PG&E will continue to operate utility lines that it owns.

Policy tributaries and interaction Each microgrid location and purpose is individual — most have many common characteristics and lie close to the main channel of policy focus, but may also have one or more important factors that are less common, and these details have big impacts.

Microgrid milestones and policy map Capabilities Single customer in island mode Grid-parallel operation Coordination with DER across the grid CPUC: Storage rules CPUC: Integrated DER CPUC: DRP CPUC: Rule 21 2017: Smart inverter standards 2008: Governor Brown’s goal: 12 GW of DG by 2020 2016: CA battery market grows by 500%/year NEM 2000: Moratorium on direct access 2007: CA Million Solar Roofs Initiative Direct access 2000: Solar PV becomes cost-effective for off-grid applications Backup diesel generators 2000 2010 2020 1990 Time

Solutions to regulatory challenges Implement a phased approach, with technology that is future-compatible Near-term: Implement behind-the-meter microgrids at critical facilities first, and stage them for the capability to participate in a future Community Microgrid. Critical facilities include essential city services (fire departments, water treatment, public works), emergency shelters at schools and churches. Automated load shedding can reduce system size and cost, but can be expensive to implement due to rewiring costs. However, there a low-cost devices that can be used to shed plug loads and individual circuits from the electrical panel. Manual load shedding is also a possibility. Systems can be designed to power critical loads within facilities indefinitely with renewable energy and energy storage. Mid-term: Work with CPUC and PG&E to incorporate renewable DER into PIH resilience zones. All customers within the PIH resilience zone will continue to have power. Load shedding can be a part of this strategy to reduce demand. PG&E will continue to operate lines they own. Design the system such that it can be deployed in the near term, but also take advantage of future regulatory advancements With the PIH configuration, PG&E will most likely be bringing in generating equipment (either diesel generators, or possibly batteries as well) Once the PIH zone is up and running, behind-the meter solar and energy storage should also resume operation as usual, thereby reducing the use of diesel generators and extending the fuel supply.

Microgrids: Policy Future Transmission TAC credit (recognizes and adds 3¢/kWh to value),  Dispatchable Energy Capacity Service (DECS) (FIT compensation for energy exports made dispatchable) Value of Resilience (VOR) Interconnection Pilot (which aims to give WDG the same advantageous streamlined treatment as NEM, making it equally fast and predictable) Using the public grid as a CM utilizing DER to meet prioritized loads, including DER behind a different customer's meter, islanding sections of the public grid for operation during grid outages, and the DERMS and MC2 required to make this work (which requires policy decisions to authorize and allocate costs) Clean Coalition is working on energy policies that have the greatest benefit for ratepayers. These are some of the policies that we’re working on now.

Community Microgrids: Economic benefits of resilience Resilience provided by Community Microgrids has tremendous value Community Microgrids: Economic benefits of resilience Powers critical loads until utility services are restored Eliminates expensive startup costs and the need to relocate vulnerable populations. Ensures continued critical services Water supply, medical and elder-care facilities, grocery stores, gas stations, shelters, communications centers. Avoids the cost of emergency shipments. Provides power for essential recovery operations Lighting for buildings, flood control, emergency shelters, food refrigeration. Minimizes emergency response expenses. Reduces dependence on diesel generators Diesel can be expensive and difficult to deliver in emergencies. Keeps businesses open Serves the community and maintains revenue streams. Includes advanced inverters + DER: Capable of riding through events that would cause older systems to shut down, and of responding to voltage and frequency excursions to mitigate these events 52

Example of PV canopy for parking Key components of the Community Microgrid will be solar PV and energy storage From: Zapotec Energy, commercial solar project in Wakefield, MA

How does energy storage provide value? Batteries for energy storage can help considerably in demand charge management for individual buildings or electric accounts, especial those with high peak usage compared to average usage, such as sites with daytime EV charging peaks. Energy storage also enables renewables-driven resilience. The graph on the right shows how a battery can help reduce on-site demand, thereby reducing demand charges The yellow part of the graph represents the daytime demand reduction from solar, and the blue part of the graph represents the demand reduction from the battery In addition, energy storage provides resilience: it enables a site to continue to operate when the grid is down, and when there is not enough solar PV production, such as in the evening or during poor-weather days.