Alameda County and Chevron Energy Solutions have developed a microgrid that enables the county’s Santa Rita Jail to sustain power should its connection to the utility grid be interrupted. The $11.7 million project, known as a smart grid, will allow the jail to ensure it has a supply of reliable electricity for its daily operations and security, and will save the county approximately $100,000 per year in energy costs. Chevron Energy Solutions designed, developed and built the project, which was funded in part by the U.S. Department of Energy, the California Energy Commission and the California Public Utilities Commission. The smart grid is the first of its kind in the country.
The jail houses as many as 4,000 inmates in 18 modern housing units and produces more than 12,000 meals per day. Covering 113 acres, the million-square-foot facility is considered a “mega-jail” and ranks as the third largest such facility in California and the fifth largest in the nation. The facility requires 3 MW of constant, reliable electricity to maintain daily operations and ensure the safety of the inmates and staff.
Interruptions to the jail’s power supply can create serious problems for the Sheriff’s Department staff and inmates housed there. The self-sustaining microgrid, also known as a smart grid, mitigates these concerns by integrating all of the jail’s onsite power generation with energy storage to ensure that power is never lost. When a disturbance to the utility grid occurs, the jail can now automatically disconnect from the grid and operate independently on clean power for up to eight hours until either local utility power is restored or conventional on-site emergency generators are engaged. The smart grid also allows the jail to buy power from the utility during the least expensive nonpeak hours and store it for use during the most expensive summer peak hours, which provides significant savings.
The project is the culmination of several renewable energy projects implemented at the jail, including solar photovoltaic panels, a 1-MW fuel cell cogeneration plant, and wind turbines, along with a 2-MW advanced energy storage system.
The California Energy Commission provided nearly $2 million in funding for the project through its Public Interest Energy Research (PIER) program. PIER supports public interest research and development that helps improve the quality of life in California by bringing environmentally safe, reliable, and affordable energy services and products to the marketplace.