A California jail has been equipped with its own "microgrid" to provide power when electricity fails in a disaster such as an earthquake, scientists say.

While a major earthquake would likely knock out power across large areas of the San Francisco Bay region, Alameda County's Santa Rita Jail, the third-largest jail in the state and fifth-largest in the country, will automatically disconnect itself from the electric grid and switch over to its own microgrid until regional power is restored, they say.

To lower its reliance on the regional grid, the jail boasts a 1.2-megawatt rooftop solar system, 1-megawatt molten carbonate fuel cell, and five small wind generators.

"Microgrids have several promising advantages," Chris Marnay, who heads the jail project for the Lawrence Berkeley National Laboratory, said in a release Wednesday. "No. 1 is that they can be tailored to local requirements, so in the case of the jail, the microgrid can help them achieve the extreme reliability their mission demands."

"Without power you don't have phones, transportation, water treatment and so on. And without communications other things don't work."

The Santa Rita Jail has intensive electricity needs, with peak demand reaching about 3.0 megawatts, so energy efficiency has long been part of the facility's strategy, officials said.

"We are excited to be hosting one of the first-of-its-kind, large-scale microgrids," Matt Muniz, Alameda County's Energy Program Manager, said. "We believe that this demonstration project will successfully exhibit the numerous advantages of microgrids and will be a model for both public agencies and private companies to emulate."