By Laurie Guevara-Stone, RMI Outlet
In 2008 the U.S. Geological Survey reported that California has a 99 percent chance of a magnitude 6.7 or larger earthquake in the next 30 years. Just last year, a 6.0 magnitude earthquake knocked out power to more than 40,000 people in the San Francisco Bay area. This was the fourth earthquake of magnitude 6 or greater to hit the Bay Area since 1979, including the 6.9 magnitude earthquake in 1989 that knocked out power to 1.4 million people. So the city of San Francisco is not taking any chances—it’s preparing for the (next) big one with microgrids.
“The whole western side of the city is built on sand; if we have a massive earthquake, the gas infrastructure will be shot, and we could face an extended power outage,” said Cal Broomhead, energy and climate program manager for San Francisco’s Department of the Environment (SF Environment). If the gas pipeline infrastructure is destroyed, it knocks out the natural gas-fired central thermal plants and prevents the use of distributed natural gas generators, so the city wanted to find a distributed solution to provide backup emergency power, one that didn’t rely on diesel.
In 2015 the city received funding from the U.S. Department of Energy’s Solar Market Pathways Program to integrate solar and energy storage into San Francisco’s emergency response plans. SF Environment is leading the project with the engineering firm ARUP acting as the primary subcontractor, and several consultants providing technical support and expertise. The local utility, Pacific Gas and Electric, one of California’s three major investor-owned utilities, is part of the grant as well.