Originally the project was to be developed as a geothermal power plant. However, after the geothermal wells were developed they would only produce 250 °F water and this was not hot enough to generate the 30 MW of electricity required to fulfill the SO4 power purchase contract with Pacific Gas & Electric Company. The developer then secured a partner and changed the plant design to a 35.5 MW biomass fired boiler and steam turbine/generator set to produce the electricity to fulfill the power purchase contract.

The plant was designed to use 600 gpm of 247 °F geothermal water passing through a plate heat exchanger as the first stage preheat for boiler feed water. The used geothermal water at 120-°F is then returned to another geothermal well for re-injection into the geothermal zone at 5300 feet. The use of the geothermal water reduces the amount of wood burned in the boiler to produce 960 °F, 1250 psi steam to the turbine.