Like many cities and counties throughout the country, the City and County of San Francisco is creating more comprehensive disaster response plans to prepare for natural disasters, including earthquakes and disasters related to the effects of climate change. As part of this effort, San Francisco explored where solar power and energy storage systems could be installed to increase neighborhood resilience. Led by the Department of the Environment (SFE) in close collaboration with other city departments, the Solar+Storage for Resiliency project explored the potential to use solar PV and energy storage systems during a large-scale grid outage.
Cities have many facilities that are critical during emergencies because of the vital support services they provide to residents. As a first step, the project team surveyed city departments to define disaster preparedness zones and identify a list of emergency facilities with critical and essential power demands.
The team created a map of buildings that are part of its existing disaster preparedness plan and overlaid it with building information like seismic ratings and tsunami zone lines. They also investigated areas where a microgrid could potentially be installed to group together multiple buildings located within two blocks of each other.
Next, the team explored the technical feasibility of installing solar+storage systems, or of retrofitting with storage buildings already equipped with solar, to enable access to the solar power generated by the system in the event of a power loss.
A map of critical facilities in San Francisco created collaboratively by the San Francisco Department for the Environment and the Emergency Management Department.
This report identifies opportunities to integrate solar+storage into San Francisco’s emergency preparedness and response plans.
A summary of the results of a workshop on the potential to retrofit the 6,500 existing PV systems within San Francisco to increase widespread availability of emergency power during a disaster.
To estimate the critical power needs (or loads) of each building, the project team worked with building managers and other city departments, including the Department of Emergency Management, to identify building functions required during an emergency.
To help with the next step in the planning process—the technical feasibility analysis—the San Francisco team created an online solar+storage critical load sizing calculator, which is free for public use. This tool helps size batteries to ensure a building has enough power to run critical loads during emergencies, and determines whether there is sufficient physical space onsite to accommodate the system. The calculator allows building owners and city departments across the country to develop preliminary solar+storage equipment sizing estimates on buildings so they can determine if solar+storage is suitable for their buildings without large upfront costs or resources.
The San Francisco team estimated the critical loads for each of their case study projects, and created a report summarizing the process.
The document outlines a three-step process used in San Francisco to determine the power loads of five types of buildings used to provide disaster relief.
The city developed four case studies of potential sites: Thurgood Marshall High School, Marina Microgrid, Hamilton Recreational Center, and Maxine Hall Health Center. To select these sites, the city identified one priority project in each of its 11 supervisory districts, then narrowed this list to the four selected sites. The case studies—along with discussions of regulatory and technical barriers with local utilities—were documented in the Resilient Solar and Storage Roadmap and the Best Practices Guide.
This report documents the financial analysis completed for the San Francisco Solar+Storage for Resilience Project, including the methodology and findings.
A two-page summary of San Francisco’s economic analysis, which concludes that a public-private partnership approach appears to be a cost-effective model for financing resilient solar.
SFE released a guide outlining efforts to deploy these systems throughout the city. The Resilient Solar and Storage Roadmap establishes the steps to implement resilient solar and serves as a model for other municipalities. The Best Practices Guide is a truncated version of the roadmap with lessons learned and strategies specifically targeted to other municipalities interested in exploring resilient solar.
Through Solar Market Pathways, SFE was able to conduct technical and financial feasibility studies to identify and address potential barriers—from permitting to fire safety—and have shovel-ready projects lined up as implementation funding becomes available. Ultimately, the city hopes to create a network of solar+storage sites that support community resilience in San Francisco’s neighborhoods.
Lessons learned and strategies specifically targeted to other municipalities interested in exploring resilient solar.
This guide establishes the steps to implement resilient solar and serves as a model for other municipalities.
In the final phase of this project (concluding December 2018), SFE will calculate an economic value for resiliency (e.g., valuing the avoided cost of disruption that solar+storage could provide)—a first-of-its-kind effort. The goal is to integrate this value of resiliency into the completed financial analysis to improve the project return on investment, and help city decision-makers determine how best to move forward (or not) with the deployment of solar+storage systems in preparation for future large-scale grid outages.