- Project Owner
- Calpine Geysers Power Company, LLC
- Docket Number
- 82-AFC-01C
- Capacity
- 41 MW
- Location
- Sonoma County
- Technology
- Steam Turbine
- Project Status
- Operational (Geothermal)
- Project Type
- Application for Certification
The Grant Geothermal Project - Unit 20 is in an unincorporated area of Sonoma County in the Geysers Known Geothermal Resource Area along the ridgeline of the Mayacamas Mountains with moderately steep terrain near the Lake County line, approximately 15 miles west of the town of Cobb. Unit 20, originally known as Pacific Gas & Electric Company’s (PG&E) Geysers Unit 20 Geothermal Project was certified by the California Energy Commission (CEC) in February 1983. Commercial operation began in October 1985.
Unit 20 was designed to provide 110-megawatts; however, due to reduced steam pressures, the plant currently (as of January 2021) supplies approximately 41-megawatts of baseload electricity to northern California's power grid. Unit 20’s major structures on the plant site are enclosed with a seven-foot security fence. These structures include a power cycle consisting of a turbine-generator and condensate and circulating water systems; a multiple cell mechanically induced crossflow cooling tower; a transmission switchyard, adjacent to the turbine generator building; and, a hydrogen sulfide (H2S) abatement system. Primary treatment will be through a Stretford system, in which H2S is scrubbed from the vent gas stream and catalytically oxidized to elemental sulfur.
In April 1999, the CEC granted a transfer of ownership of Grant Geothermal (Unit 20), the former PG&E Geysers Unit 20 Geothermal Project to Geysers Power Company, LLC, a wholly owned subsidiary of the Calpine Corporation.
- Settlement for Fire Protection System
Commission Approval
Order No. 20-1116-02
TN 235698
11/19/2020 - Resolution for (DCBO) Services for Fire System Recommissioning Activities
Commission Approval
Resolution No. 19-1014-04
TN 230281
10/18/2019 - Replacement of Temporary Portable Emergency Diesel Engines with Stationary Permanent Emergency Diesel Engines
Commission Approval
Order No. 18-1210-02
TN 226129
12/17/2018 - Authorization of the Revised ATC Incorporated into the project Final Decision
Executive Order B-36-16
TN 210233
02/08/2016 - Authorization for Calpine to Obtain Demolition Permits from Sonoma and Lake Counties for Demolition
Staff Approval
TN 206701
11/19/2015 - Use of Reclaimed Wastewater and Approval of Verification Changes
Staff Approval
TN 31101
03/12/2004 - Ownership Transfer to Geysers Power Company
Commission Approval
Order No. 99-0414-01b
TN 11769
04/22/1999 - Modification of Verifications for Air Quality and Public Health Conditions of Certification
Staff Approval
Not in Docket
03/23/1995 - Modification of Biological Resources, Waste Management, and Power Plant Efficiency and Reliability Conditions of Certification
Commission Approval
Order No. 95-0315-09
TN 8882
05/25/1995 - Modification of Tapline Termination and Amending Certification Decision
Commission Approval
Order No. 85-0501-01
Not in Docket
05/03/1985
Attention: You will need to look up the transaction number (TN) in the Compliance Docket Log. Non-hypertext items in the docket indicate that no electronic or hard copy is available or the item was filed confidentially. If you have any questions, please contact the Compliance Project Manager assigned to this project.
Power Plant Certification and Exemption Processes
The CEC has the exclusive authority to certify all thermal power plants 50 megawatts (MW) and larger and related facilities proposed for construction in California. The Application for Certification (AFC) process is a certified regulatory program under the California Environmental Quality Act (CEQA). As a certified regulatory program, the CEC does not prepare environmental impact reports (EIRs) in an AFC proceeding, but instead prepares environmental assessment documents that are functionally equivalent to EIRs. A certificate issued by the CEC is in lieu of any permit, certificate, or similar document otherwise required by any state, local or regional agency, or federal agency to the extent permitted by federal law, and supersedes any applicable statute, ordinance, or regulation of any state, local, or regional agency, or federal agency to the extent permitted by federal law.
Original Proceeding
e-Commenting has been closed. Please submit your comments in compliance proceeding above.
Contacts
Project Manager
Rena Eddy
CME@energy.ca.gov
(Please enter project name in the email subject line)
916-796-5815
Public Participation Questions
Public Advisor
publicadvisor@energy.ca.gov
916-269-9595
Media Inquiries
Media & Public Communications Office
mediaoffice@energy.ca.gov
916-654-4989