- Docket Number
- 72 MW
- Sonoma County
- Steam Turbine
- Project Status
- Operational (Geothermal)
- Project Type
- Application for Certification
The Sonoma Geothermal project (Unit 03) is in Sonoma County near the Sonoma/Lake County line, in the Geysers Known Geothermal Resource Area along the ridgeline of the Mayacamas Mountains with moderately steep terrain, approximately 15 miles west of the town of Cobb. Unit 03, originally known as Sacramento Municipal Utility District (SMUD) SMUDGEO No. 1 Geothermal Project (SMUDGEO1), was certified by the California Energy Commission (CEC) in March 1981 and began commercial operation in December 1983.
Unit 03 is a dry steam geothermal power plant and was designed to provide 78 MW of electricity; however, due to reduced steam pressures, Unit 03 currently provides 35 MW of baseload power to northern California’s power grid.
Prior to the project being licensed, a Memorandum of Understanding dated February 27, 1980, between the CEC, United States Geological Survey (USGS), and the Bureau of Land Management, was prepared to create a cooperative effort to comply with National Environmental Policy Act and California Environmental Quality Act and to issue the necessary permits and licenses for the project.
On February 3, 1981, a Letter of Understanding (LOU) was signed by the CEC and USGS to further clarify duties and responsibilities of the agencies following the issuance of the licenses and approvals for the project. The LOU stated that the ultimate decision-making authority over the operation of the facility resided with the USGS and the BLM. The LOU required Plans of Operation, Applications for Permits, reports, designs, and similar documents to be submitted to the USGS and reviewed by the CEC. All annual reports of compliance were to be submitted to the USGS.
The 1981 Final CEC Decision stated that state and federal agencies participated in a joint environmental statement since the project is on federal lands. The conditions set forth in the Final Decision were consistent with the MOU and the LOU and required the project owner to file various report and other ongoing compliance documents with the USGS.
In April 1999, the CEC granted a transfer of ownership of the Sonoma Geothermal (Unit 03), the former Sonoma Geothermal Power Project (formerly SMUDGEO) from Calpine Geysers Company, L.P. to Geysers Power Company, LLC, a wholly owned subsidiary of Calpine Corporation. In August 2010, the CEC approved a USGS letter requesting that they be terminated as the primary compliance monitoring agency.
Resolution approving Transmission Tapline Reroute, Not in Docket, 05/19/1982, Order No. 82-0519-01, Commission approval of transmission tapline reroute to avoid existing steam well development sites.
Commission Order Approving Transfer of License, TN 9021, 07/14/1998, Order No. 98-0624-01a, Commission approval of ownership transfer from SMUD to Calpine Geysers Company.
Commission Order Approving Ownership Transfer, TN 11794, 04/22/1999, Order No. 99-0414-01c, Commission approval of ownership transfer from Calpine Geysers Company LP to Geysers Power Company.
Approval of Petition to Use Reclaimed Wastewater and Approval of Verification Changes, TN 31109, 03/12/2004, Staff approval of the use of reclaimed municipal wastewater at the six Calpine Geysers geothermal power plants as well as revision of the reporting requirements in the condition of certification verifications.
Order Approving the Termination of the MOU and LOU Between the Energy Commission and the United States Geological Survey; and Amendment of the Final Decision, TN 58491, 09/16/2010, Order No. 10-0825-01a, Staff approval of termination of the MOU and LOU between the CEC and the United States Geological Survey.
Authorization for Calpine to Obtain Demolition Permits from Sonoma and Lake Counties for Demolition, TN 206646, 11/16/2015, Staff approval for Calpine to obtain and implement county-issued demolition permits to abate fire damage to structures at Geysers 16, 18, and 20.
Expedited Processing Pursuant to Executive Order B-36-15 for Fire Damage Repair, TN 207294, 01/13/2016, Executive Director approval of repair, reconstruction, and/or replacement-in-kind of the cooling tower damaged in the recent Valley Fire.
Resolution Approving (DCBO) services for fire system recommissioning activities at the Geysers Facilities, TN 230276, 10/18/2019, Resolution No. 19-1014-04, Approval of Agreement 700-19-003 with NV5, Inc. for a $0 contract to provide delegate chief building official services for fire system recommissioning activities at the Geysers facilities.
Order Approving Petition to Install a Permanent Standby Diesel Engine, TN 235329, 10/20/2020, Order No. 20-1014-04, Commission approval to install a permanent standby diesel engine powered pump for the cooling tower wet-down system.
Order Approving Settlement for Fire Protection System at the Six Geyser Facilities, TN 235703, 11/19/20, Order No. 20-1116-02, Commission approval of the Settlement Agreement and changes to the conditions of certification and direct the Executive Director to execute the Settlement Agreement on behalf of the CEC.
Attention: Non-hypertext items above will need to be requested from the Compliance Project Manager, along with the document TN number, if provided above.
Power Plant Certification and Exemption Processes
As required by the Warren-Alquist Act, the Energy Commission monitors Commission-certified energy projects throughout construction, operation, and closure to ensure compliance with the conditions of certification imposed by the Commission’s Final Decision for approving the projects.