NCPA Geothermal Plant No. 1 (Formerly NCPA 2)

Northern California Power Agency (NCPA) Geothermal Plant No. 1 (NCPA-1) is located in located on a federal land approximately 60 miles northwest of Sacramento on the Sonoma County side of the Mayacmas Mountain ridgeline above the Big Sulphur Creek and Bear Canyon Creek drainages, just west of the Sonoma/Lake County line. The project is located in an unincorporated area of Sonoma County near the town of Anderson Springs. Geothermal steam wells, which supply the project are located in both Sonoma and Lake Counties.

NCPA-1 is a 110-megawatt generating geothermal facility consisting of steam wells, steam gathering system and reinjection wells of the steam supplier, a power plant and transmission tapline. NCPA-1 includes two 55 MW steam turbine-generator units, each capable of operating separately, if necessary, during scheduled or unscheduled shutdowns. Each turbine-generator has its own condensing system, cooling tower and electrical sub-station to step-up the voltage for transmission. The primary H2S abatement system uses a surface condenser to partition the spent steam, into condensate and non-condensable gases and solids that are treated by the Stretford System, which then scrubs heat from the H2S from the vent gas stream from the condenser and catalytically oxidizes the gas to eliminate Sulfur.

NCPA-1 was licensed as NCPA-2.

On June 1, 2020, the California Energy Commission staff approved the modernization of fire protection system for the purpose of replacing the degraded existing system and defective control panels. The recommissioning of the upgraded fire protection system is currently underway.