Powering Strong Communities

SMUD Board Approves 100-MW Geothermal Energy Contract With Calpine

California public power utility SMUD has approved a 100-megawatt (MW) contract with Calpine Corporation for geothermal power from The Geysers. The move marks a major step forward toward the SMUD’s 2030 zero carbon plan.

The 10-year power purchase agreement for 100 MW of energy from Calpine’s operations at The Geysers was approved by the SMUD Board of Directors on March 16. The contract takes effect on January 1, 2023.

Located north of San Francisco, The Geysers is the single largest geothermal electrical operation in the world.

A geothermal resource occurs when water deep below the earth’s surface is heated by exposure to hot, porous and permeable rock resulting in dry steam or hot water.

At The Geysers, dry, superheated steam is produced. Steam production wells about two miles deep are drilled to tap this naturally occurring steam. Once the steam reaches the surface, it is piped overland to a network of interconnected power plants where it spins conventional steam turbines that drive generators.