Colorado Public Utilities Commission approves Tri-State’s 2023 Electric Resource Plan 

(August 26, 2025, Westminster, Colo.) – The Colorado Public Utilities Commission (PUC) today issued written approval of Tri-State’s 2023 Electric Resource Plan (ERP) Phase II preferred portfolio. The PUC voted in favor of the plan on Aug. 1, but today’s formal approval is an important step to allow Tri-State to begin to seek contracts for the resources in the portfolio.  

The preferred portfolio exceeds both industry-standard and Tri-State’s heightened extreme weather reliability metrics while meeting state requirements for GHG emissions reductions and renewable energy/portfolio standards and does so at a lower cost than the alternatives. The portfolio reflects:  

• 1,350 MW of renewable, hybrid and standalone short-term storage resources;  

• A 307 MW natural gas combustion turbine facility with hydrogen-blend capability located in Moffat County;   

• Replacement of five existing combustion turbines at JM Shafer Station, bringing the station’s nameplate capacity to 281 MW; and

• Previously announced retirements for Craig Station Unit 1 at the end of this year and Units 2 and 3 in 2028; and Springerville Station Unit 3 in 2031 with agreements from other parties and subject to receiving federal funding as requested. 

“I want to thank our members, employees, the commission, and the many stakeholders who have spent countless hours developing our ERP,” said Tri-State CEO Duane Highley. “In an uncertain energy environment, this plan provides direction and a positive step forward. We look forward to implementing a portfolio that will benefit our members now and well into the future, even as we navigate the hurdles ahead.” 

Tri-State’s approved 2023 ERP marks a significant milestone. Tri-State will continue to evaluate the next steps forward to pursue this portfolio to develop a mix of resources that delivers reliable, affordable and responsible power to our members and communities.   

About Tri-State    

Tri-State is a power supply cooperative, operating on a not-for-profit basis, serving electric distribution cooperatives and public power district member-owners in four states. Together with our members, we deliver reliable, affordable and responsible power to more than a million electricity consumers across nearly 200,000 square miles of the rural West. Visit www.tristate.coop.    

Contact:    

Amy Robertson, 303-254-3743, amy.robertson@tristategt.org    

Mark Stutz, 303-254-3183, mark.stutz@tristategt.org    

Certain information contained in this press statement are forward-looking statements including statements concerning Tri-State’s plans, future events, and other information that is not historical information. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those described from time to time in Tri-State’s filings with the Securities and Exchange Commission. Tri-State’s expectations and beliefs are expressed in good faith, and Tri-State believes there is a reasonable basis for them. However, Tri-State cannot assure you that management’s expectations and beliefs will be achieved. There are a number of risks, uncertainties and other important factors that could cause actual results to differ materially from the forward-looking statements contained herein.    

FERC accepts Tri-State’s new Wholesale Electric Service Contracts and amended board policy expanding member flexibility  

(August 5, 2025, Westminster, Colo.) — The Federal Energy Regulatory Commission (FERC) has accepted Tri-State Generation and Transmission Association’s new Wholesale Electric Service Contracts (WESCs) and an amended Board Policy 115, effective August 6. The filings are set for settlement and hearing procedures and are subject to refund.  

The newly accepted contracts and policy mark a significant step forward in providing greater flexibility for Tri-State’s utility members and allows Tri-State to optimize its resource and financial planning for the future. Thirty-six Tri-State members, representing 98% of the association’s total continuing load, have executed the new contracts, which include terms of either 2050 or extending to 2066. Under the revised Board Policy 115, members can now self-supply up to 20% of their energy needs through distributed or renewable generation, a substantial increase from the previous 5% allocation.    

“FERC’s acceptance of the new WESC and revised Board Policy 115 delivers certainty and opportunity to Tri-State and our members,” said Duane Highley, Tri-State Chief Executive Officer. “Together, we remain committed to delivering reliable, affordable power to rural communities for generations to come.”  

Tri-State continues to work collaboratively with its members to ensure a resilient and responsible energy future.  

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About Tri-State   

Tri-State is a power supply cooperative, operating on a not-for-profit basis, serving electric distribution cooperatives and public power district member-owners in four states. Together with our members, we deliver reliable, affordable and responsible power to more than a million electricity consumers across nearly 200,000 square miles of the rural West. Visit www.tristate.coop.   

Contact:   

Amy Robertson, 303-254-3743, amy.robertson@tristategt.org   

Mark Stutz, 303-254-3183, mstutz@tristategt.org   

Certain information contained in this press statement are forward-looking statements including statements concerning Tri-State’s plans, future events, and other information that is not historical information. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those described from time to time in Tri-State’s filings with the Securities and Exchange Commission. Tri-State’s expectations and beliefs are expressed in good faith, and Tri-State believes there is a reasonable basis for them. However, Tri-State cannot assure you that management’s expectations and beliefs will be achieved. There are a number of risks, uncertainties and other important factors that could cause actual results to differ materially from the forward-looking statements contained herein.