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Grays Harbor Energy Center

The Grays Harbor Energy Center (Project) consists of two combustion turbine generators on a "two on one" configuration with a single steam turbine generator. The Project produces a nominal output of approximately 530 megawatts, with a maximum output of approximately 650 megawatts. The Project is located on a 20-acre site within the Satsop Redevelopment Park in Grays Harbor County (location map). The entire 20-acre site was previously developed, including grading and surfacing with gravel and asphalt, and used as an equipment and material laydown area during construction of WNP-3 and WNP-5.

The Site Certification Agreement (SCA) for the Satsop Nuclear Project (WNP 3/5) site was amended in 1996 to allow for construction of a 450 MW gas turbine project. The nuclear power projects were removed from the SCA in 1999. In April 2001, the SCA was amended again to license the current 650 MW gas turbine project. Construction started on the combustion turbine project in September 2001, but was suspended in September 2002 at approximately 56% completion.

In April 2005, the Site Certification Agreement was amended to reflect the sale of the project to Grays Harbor Energy LLC (GHE, a subsidiary of Invenergy Inc.) from Duke Energy. Construction was restarted in February 2007 with commercial operation starting in April 2008.

On October 30, 2009, GHE submitted a Request for Amendment to the SCA. GHE requested a 650 megawatt increase in the facility capacity (to a total maximum output of approximately 1,300 megawatts), a change the facility name to Grays Harbor Energy Center, an expansion of the site by 10 acres, approval of a PSD permit for the new units, and an increase in the total maximum water usage from 9.2 cfs to 16.0 cfs.

For a detailed description of the amendment process and access to relevant documents, please see the Request for Amendment webpage.

On December 21, 2010, EFSEC issued Council Order No. 860, recommending that the governor approve GHE's amendment request. The governor approved the amended SCA on February 18, 2011.

Certificate Holder: Grays Harbor Energy LLC
PO Box 26
Satsop, WA 98583
(360) 482-4353
Facility Status:

Phase 1 consists of the existing 650 MW natural gas-fire combined cycle combustion turbine project and is operational.

Phase 2 consists of the proposed 650 MW expansion. Phase 2 has been approved but is not yet constructed.

Status: Commercial operation of Phase 1 began April 25, 2008.

Site Certification Agreement:

Site Certification Agreement: PDF

Attachment 1 - Site Legal Description
Attachment 2 - NPDES Permit
Attachment 3 - Water Withdrawal Authorization
Attachment 4 - Mitigation Measures
Attachment 5 - PSD

Greenhouse Gas Mitigation - Attachments to the SCA

Greenhouse Gas Mitigation Plan - Approved by EFSEC June 9, 2003
Carbon Dioxide CO2 Mitigation Payment Clarification Letter --February 14, 2008

Units 1 & 2 PSD/NOC

Units 3 & 4 PSD/NOC

Project History:

The Council completed its review of the Satsop Combustion Turbine Project, Application No. 94-1, and the Governor signed the Site Certification Agreement on May 21, 1996.

In February 2001, the Council authorized a technical amendment to the Site Certification Agreement, allowing the addition of Duke Energy Grays Harbor, LLC, as a Site Certification Agreement co-permittee.

In April 2001, the Council authorized a technical amendment to the Site Certification, allowing:

  • The replacement of the originally permitted Westinghouse turbines with General Electric turbines;
  • A modification of the facility configuration from a dual one-on-one configuration (two separate but identical combustion turbine generator - steam turbine generator trains), to a single two on one configuration (two combustion turbine generators - one steam turbine generator facility);
  • An increase of the nominal output of the facility from 490 MW to 530 MW;
  • An increase of the maximum output of approximately 650 MW by utilizing duct firing;
  • And removal of the capability to use diesel oil as a backup fuel.

Construction started on the combustion turbine project in September 2001 but was suspended in September of 2002 at approximately 56% completion

In April 2005, the Site Certificate was amended to reflect the transfer of ownership from Duke Energy to Grays Harbor Energy LLC (a subsidiary of Invenergy Inc.).

Invenergy restarted construction in February 2007.

For information or questions concerning this project please contact:

         Energy Facility SiteEvaluation Council
         1300 S Evergreen Park Dr SW
         PO Box 47250
         Olympia, WA 98504-7250
          (360) 664-1345

To be added to the Satsop CT Project mailing list, please:

  • E-mail your complete name and postal address to and indicate if you want to receive notices of future permitting activity for this project by e-mail, surface mail, or both methods of delivery.

Top of page

Project Milestones:

July 17, 2018 - Final Approval of the Prevention of Significant Deterioration (PSD) and Notice of Construction (NOC) permit

May 16, 2018 - Draft Prevention of Significant Deterioration (PSD) and Notice of Construction (NOC) permit
Comment period CLOSED

April 20, 2017 Approved Notice of Construction Tower Replacement Project

March 27, 2017 - Grays Harbor Energy Center Cooling Tower Repair Project
-Receipt of Notice of Construction Application and Opportunity for Public Comment
-EFSEC Issues Determination of Nonsignificance (DNS)
-Permit application
-SEPA checklist
-PSD 2006

April 19, 2016 - Order 876 to Revise the Schedule of Compliance in National Polluntant Discharge Elimination System (NPDES) Permit No. WA-002496-1

October 26, 2012 - EFSEC Issues Determination of Application Completeness Letter

April 10, 2012 - GHE Request to Extend Units 3 & 4 PSD/NOC Permit (in process)

March 9, 2012 - Grays Harbor Energy NOV Special Meeting Minutes

March 7, 2012 - Grays Harbor Energy Notice of Special Meeting

February 18, 2011 - Grays Harbor Energy - Governor's Approval Letter, Final Order, Final SCA

November 10, 2009 - Request for Expedited Processing and SEPA Checklist for Amendment No. 5 request.

October 30, 2009 - Request to amend the SCA to increase capacity by 650 MW by adding new Units 3 & 4, change the name to Grays Harbor Energy Center, issue a new PSD for Units 3 & 4, and increase total project water use.

April 3, 2006 - Final NOC/PSD Permit issued

Final Permit Documents:

March 2005 - Transfer of Ownership to Invenergy: In early February 2005 EFSEC received a request to transfer the ownership of the Satsop Combustion Turbine Project.

In March 2005 EFSEC approved the requested transfer of ownership from Duke Energy Grays Harbor with Invenergy's finalization of the transactions between Duke Energy Grays Harbor and Invenergy, and EFSEC's receipt of a financial guarantee of funds for site restoration.

Links to pertinent documents are listed below:

March 15, 2005 - Order on Financial Assurances for Site Restoration

February 25, 2005 - Order on Application for Transfer once certain conditions are met.

February 25, 2005 - Financial analysis of Invenergy

February 7, 2005 - Determination of Non-Significance regarding Consideration of Request to transfer ownership of Satsop CT

February 3, 2005 - Duke Energy Request to transfer ownership of Satsop CT to Invenergy - Public Meeting scheduled for February 23, 2005.


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