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 is deploying solar power and energy storage systems that will increase neighborhood resilience. Led by the Department of the Environment in close collaboration with other city departments, San Francisco’s Solar+Storage for Resiliency project incorporated solar+storage systems into its existing disaster preparedness plans, which now serve as models for other cities.
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 showing which buildings are part of its existing disaster preparedness plan—with solar installed and access to power—should a disaster strike. They also identified 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.
The city considered pilot projects in different neighborhoods, selecting a priority project in each of the city’s 11 supervisory districts, then narrowed this selection to four potential sites: Thurgood Marshall High School, Marina Microgrid, Hamilton Recreational Center, and Maxine Hall Health Center.
A map of critical facilities in San Francisco created collaboratively by the San Francisco Department for the Environment and the Emergency Management Department.
To estimate the critical power needs (or loads) of each building, the project team worked with the Department of Emergency Management and other city departments 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. 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 San Francisco calculator, which is free for public use, allows building owners and city departments across the country to develop preliminary solar+storage equipment sizing estimates on a portfolio of buildings so they can incorporate optimum scenarios into their energy resilience strategies.
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 is creating a set of case studies to illustrate barriers and decision points in the technical feasibility analysis. One such case study will describe the process of adding batteries to an existing solar energy system at a school designated as an emergency shelter. The case studies—along with discussions of regulatory and technical barriers with local utilities—will be documented in the Solar+Storage Roadmap and Best Practices Guide, which will be published later this year.
In late 2017, the city will release a Solar+Storage Roadmap describing San Francisco’s efforts to deploy these systems throughout the city. Additionally, the city will publish a Best Practices Guide and other resources supporting the implementation of solar+storage to serve as a model for other cities with similar goals.
Current funding supports technical and financial feasibility analyses. The city’s goal is 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 help support community resilience in San Francisco’s neighborhoods.