Project Owner
Sacramento Municipal Utility District Financing Authority
Docket Number
603 MW
Sacramento County
Combined Cycle
Project Status
Operational (Natural Gas-Fired)
Project Type
Application for Certification
Project Description

The Cosumnes Power Plant (CPP) is located adjacent to the Rancho Seco Nuclear Plant, 25 miles southeast of the city of Sacramento, Sacramento County.

The CPP is a nominal 603-megawatt (MW) combined-cycle, natural gas-fired facility consisting of two combustion turbines, one condensing steam turbine, and two heat recovery steam generators. The transmission line consists of 0.4 miles of new 230-kilovolt line from the on-site switchyard to the existing switchyard at Rancho Seco. The natural gas line is supplied by 26-miles of the district-owned gas line. The line is located between the project site and the Carson Ice-Gen Facility, in Sacramento County. A 0.4-mile connection to the existing 66-inch diameter water line conveys water from the Folsom-South Canal.

The original Application for Certification was for a two-phase project, each phase consisting of 500 MW. Phase 2 was never constructed. In the event the Sacramento Municipal Utility District (SMUD) files an Application for Certification for Phase 2 (500 MW) of the project, the CEC’s review will be limited to Air Quality, Water Resources (including the use of recycled water for cooling based upon the stipulation between SMUD and Commission staff), and Transmission System Engineering unless any of the circumstances identified in the CEQA Guidelines, section 15162 (a)(1)-(3) regarding substantive changes or new information have occurred or there have been changes to applicable law.

On December 10, 2018, the CEC approved a Post-Certification Amendment (TN 226231) to operate previously installed Advanced Gas Path upgrade components, Dry-Low Nitrogen 2.6+ combustors, and oxidation catalyst emission control systems. This would increase electrical production from each of the two licensed combustion turbine generators from 170 MW to 198 MW, an increase of 56 MW total. The overall CPP electrical output would increase from 534 MW to 603 MW, an increase of 69 MW.

On July 15, 2021, SMUD filed a Notification of Name Change for the project. The change removed SMUD from the name, changing it from SMUD Cosumnes Power Plant to Cosumnes Power Plant.

  • Notice of Insignificant Project Change for Approval to Install Temporary Concrete Batch Plant, TN 30799, 01/29/2004, Staff approval of the installation of a temporary concrete batch plant.
  • Approval of Petition to Relocate Water Supply Line, TN 30641, 01/28/2009, Staff approval of relocation of the water supply line.
  • Order Approving Ownership Transfer, TN 35811, 10/26/2005, Order No. 05-1019-01-(a), Commission approval of transfer of ownership to Sacramento Municipal Utility District Financing Authority.
  • Order Approving Modification to Air Quality Conditions of Certification, TN 46617, 06/06/08, Order No. 08-0604-01, Commission approval to modify Air Quality Conditions of Certification.
  • Insignificant Project Change for Approval to Upgrade ZLD, TN 51120, 04/16/2009, Staff approval of Upgrade ZLD and installation of OnePass filtration system.
  • Insignificant Project Change for Approval to Relocate Segment of Gas Pipeline, Not in Docket, 04/28/2009, Staff approval of relocation of a one-mile segment of 26-mile natural gas pipeline.
  • Non-Petition Approval to Move Main Entry Gate, Not in Docket, 07/19/2010, Staff approval of the request to move the east (main) entry gate 130 feet to the north.
  • Order Approving Modification to Fuel Supply, TN 62843, Order No. 11-1102-05, Commission approval to modify the project fuel supply.
  • Order Approving Operation of Installed Advanced Gas Path Upgrades, TN 226231, 01/07/2019, Order No. 18-1210-04, Commission approval of Phase 2, Operation of previously installed AGP upgrade components, Dry-Low Nitrogen 2.6+ combustors, and oxidation catalyst emission control systems
  • Staff Approved Project Change to Add New Candle Filter Press, Not in Docket, 02/06/2019, Staff Approval of installation of new Candle Filter Press and associated structures.
  • Authorization of Replacement of ZLD Evaporator and Sump Vessel, 8/28/2019, Non-Petition Staff Approval to replace the zero liquid discharge evaporator and sump vessel at the project.
  • Statement of Staff Approval to Modify Condition of Certification AQ-30, TN 233809, 07/08/2020, Staff approval to modify condition of certification AQ-30 to correct an error in staff’s 2018 analysis (TN 225863) for Order 18-1210-04.
  • Notice of Administrative Name Change, TN 238883, 07/15/2021, The project name Cosumnes Power Plant (Sacramento Municipal Utility District) is changed to Cosumnes Power Plant.


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.

Original Proceeding

e-Commenting has been closed. Please submit your comments in compliance proceeding above.

Docket Log (01-AFC-19)

Exhibit List

Proof of Service List

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Mary Dyas

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