Resource planning
Electric resource planning (ERP) for resources involves developing and assessing alternative scenarios based on a range of growth rates, resource costs, capital costs, types of generation resources, energy efficiency programs, levels of emissions, water usage and other considerations. Various resource plan scenarios are compared on the basis of cost, reliability, environmental characteristics and other factors.
Operating under the cooperative principles, Tri-State seeks to keep members and the public informed. Your participation in this process is encouraged.
2023 ERP / IRP Planning
Following the conclusion of Tri-State’s Phase II 2020 ERP (Proceeding No. 20A-0528E), Tri-State will be filing a Phase I 2023 ERP, which will also be submitted to the Western Area Power Administration (WAPA) for compliance with their Integrated Resource Planning (IRP) requirements (10 CFR part 905) for their customers, in 2023. The anticipated Resource Planning Period (RPP) to be covered by the 2023 ERP is 2024-2043.
A stakeholder meeting to discuss 2023 ERP Phase II planning will be held virtually on Sept. 27, 2023, at 10:30 a.m. (This meeting was originally scheduled to be held on September 14, 2023, but was rescheduled).. Interested persons are encouraged to contact sruen@tristategt.org to receive the calendar invite.
Interested parties may provide input to Tri-State's 2023 IRP via email at resourceplanning@tristategt.org. This email inbox will be monitored by Tri-State throughout 2023. During this period, Tri-State will post input received via this inbox including issues, questions or concerns from the public, along with any applicable responses on the Stakeholder Outreach page of Tri-State's website: https://www.tristate.coop/statekholder-outreach.
2020 ERP Filing
To view the 2020 ERP filings, go to the Colorado Public Utilities Commission (PUC) Electronic Filings web page. Search for Documents under Proceeding Number 20A-0528E. The RPP covered by the 2020 ERP was 2021 to 2040.
Tri-State’s Phase I 2020 ERP concluded on April 18, 2022 through an uncontested comprehensive settlement agreement. Tri-State’s Phase II 2020 ERP was initiated on May 18, 2022 with the release of a Request for Proposals for clean generation resources with commercial operations dates in 2025 or 2026.
2020 IRP Public Process
Click here to view the IRP document that was filed with WAPA in 2020.
Tri-State's Resource Planning Process:
Tri-State runs a base case along with various scenarios which represent the anticipated financial, environmental, and reliability impacts of potential variations in forecasting assumptions. The purpose of the base case and scenarios is to identify Tri-State's resource needs within the RPP and the most reliable, cost-effective way to fill that need.
The scenario process begins with an expansion plan modeling that is used to identify the most reliable, cost-effective plan for a given scenario. From there, the expansion plan is dispatched in an hourly production cost model, and the results along with other financial data related to resources, including but not limited to transmission and generation build capital expenses, are sent to financial models to determine the final Present Value Revenue Requirement of each scenario.
Tri-State considers both supply and demand side resources in regards to expansion planning. Both build and purchases options are considered. Generic resources are modeled as available throughout Tri-State's system to the extent they are utility-scale and proven technologically and financially feasible.
Resource planning documents
2023 Standard Offer Avoided Cost
2022 ERP Annual progress report
2021 ERP Annual progress report
2022 Annual report to Colorado PUC on RES compliance
2021 Annual report to Colorado PUC on RES compliance
2020 Annual report to Colorado PUC on RES compliance
2019 Annual report to Colorado PUC on RES compliance
2019 ERP Annual progress report
2018 REP Annual progress report
2018 Annual report to Colorado PUC on RES compliance
2017 ERP Annual progress report