Project Owner
Geysers L.L.C.
Docket Number
97 MW
Lake County
Steam Turbine
Project Status
Operational (Geothermal)
Project Type
Application for Certification
Project Description

The Calistoga Geothermal Project (Unit 19) is in Lake 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 19, originally known as Occidental (Oxy) Geothermal Power Plant No. 1 (Oxy #1) was certified by the California Energy Commission (CEC) in February 1982, and the plant began commercial operation in April 1984.

Unit 19 was designed to provide 80 megawatts of base-load electricity to northern California's power grid; however, due to reduced steam pressures, Unit 19 currently (as of January 2021) provides 69 MW of baseload power. Unit 19 major structures include the turbine building, cooling towers, hydrogen sulfide abatement, and the service building.

Between 1982 and 1999, OXY No. 1 underwent several ownership transfers and name changes within corporate entities, In November 1984, Occidental Geothermal, Inc. stock was purchased by Santa Fe International Corporation and the name was changed to Santa Fe Geothermal Plant No. 1. In April 1997, Santa Fe International Corporation sold Santa Fe Geothermal, Inc. to ESI Geothermal, Inc. (a division of Florida Power & Light (FPL) that was subsequently renamed FPL Energy). ESI renamed Santa Fe Geothermal, Inc. Silverado Geothermal Resources, Inc. (Silverado). Silverado immediately sold the power plant to Calistoga Geothermal Partners, LP.

In November 1999, the CEC granted a transfer in ownership of Unit 19 from Calistoga Geothermal Partners, LP to Geysers Power Company, LLC, both indirect wholly owned subsidiaries of Calpine Corporation. Calpine purchased 100 percent of the stock in Calistoga Geothermal Partners, LP and Silverado and renamed the facility Calistoga (Unit 19).


Compliance Committee Order Approving Modification of Tap-Line Route Alternate B, Not in Docket, Order No. 82-1130, Commission approval to modify "Alternate B" route described in the Commission's Decision. 

Order for Oxy Geothermal No. 1. Tap-Line Changes, Not in Docket, Order No. 84-0905-08a, Commission approval of route change and engineering design changes. 

Commission Order Approving License Transfer, Not in Docket, TN 3453, 11/04/1996, Order 96-1030-1(b), Commission approval of license transfer from First Trust of California, National Association to Sante Fe Geothermal, Inc. 

Commission Order Approving License Transfer, TN 4460, 04/18/1997, Order No. 97-0402-01a, Commission approval of license transfer from Santa Fe Geothermal, Inc. to Calistoga Geothermal Partners, LP. 

Commission Order Approving Ownership Transfer, TN 12788, 11/23/1999, Order No. 99-1117-01c, Commission approval of ownership transfer from Calistoga Geothermal Partners, LP to Geysers Power Company. 

Approval of Petition to Use Reclaimed Wastewater and Approval of Verification Changes, TN 31105, 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 a Petition to Modify Biological Resources Condition of Certification 5-4, TN 47102, 07/18/2008, Order No. 08-0716-03, Commission approval to modify Condition of Certification BIO 5-4 to allow that five-year boron drift monitoring continues until confirmation that boron drift is not having significant impact on surrounding vegetation and further monitoring no longer required. 

Staff Approval of Replacing Existing Underground 21 kV standby Circuit with an Aboveground Line, TN 229202, 08/02/2019, Staff approval of Replacement of existing underground 21-kilovolt (kV) standby circuit with an aboveground line. 

Resolution Approving (DCBO) services for fire system recommissioning activities at the Geysers facilities, TN 230280, 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 (DCBO) services for fire system recommissioning activities at the Geysers facilities.  

Order Approving Installation of a Permanent Standby Diesel Engine-Powered Pump, TN 235330, 10/20/2020, Order No. 20-1014-3, Commission approval to install a permanent standby diesel engine-powered pump for the cooling tower wet-down system. The equipment upgrade would change operational characteristics and require changes to air quality conditions of certification. 

Order Approving Settlement for Fire Protection System, TN 235699, 11/19/2020, 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

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.

Docket Log (81-AFC-01)

Exhibit List

Proof of Service List

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