Resource planning | Tri-State Generation and Transmission Association, Inc

Resource planning

Planning 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. The various alternative resource plans are compared on the basis of cost, 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.

2020 ERP Documents

To view the 2020 ERP filings, go to the Colorado Public Utilities Commission Electronic Filings web page. Search for Documents under Proceeding Number 20A-0528E or PUBLIC Attachment BN-2 to Direct Testimony of Brad Nebergall [Hearing Exhibit 101].

2020 IRP Public Process

Click here to view the IRP document that was filed with Western Area Power Administration and Colorado Public Utilities Commission.

Earlier this year Tri-State posted a notice regarding the postponement of public meetings related to its 2020 Integrated Resource Planning (IRP) process in the interest of public safety due to COVID-19. Given that public safety issues due to COVID-19 are still of high concern, Tri-State has decided to utilize a virtual approach to receiving and responding to public input and concerns in regards to our 2020 IRP. The following information is meant to provide insight into Tri-State's 2020 IRP scenario focus as well as to identify a means for the public and Tri-State to interact.

Tri-State's 2020 IRP Scenario focus:

Tri-State is focusing its 2020 IRP on key uses that may have significant reliability, economic and/or environmental impact to Tri-State's Utility Member Systems. These issues are identified as follow:

Changes to Tri-State's load forecast driven by increased flexibility in how Tri-State Utility Member Systems serve their load
Changes to Tri-State's load forecast driven by Tri-State Utility Member System customer adoption of newer technology
Regulatory requirements throughout Tri-State's Member Service Territory including Renewable Portfolio Standards, Renewable Energy Standards and Greenhouse Gas Emissions reductions
Member Exit from Tri-State Membership

As part of Tri-State's overall IRP process, a Resource Planning Period (RPP) of 2021 to 2040 was chosen. Tri-State will run a base case along with various scenarios which will represent the impacts of the above items. 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 planning tool that is used to identify the most reliable, cost-effective plan for a given scenario. From there the 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. The final assessment of all scenarios will be based on a combination of dispatchability, diversity, environmental impacts and economic impacts to Tri-State's Utility Member Systems.

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 technologically feasible. Generic resources available in the expansion planning process include:

Renewables - Wind and Solar
Energy Storage - Utility Scale Batteries and Pumped Storage
Gas Fueled Plants - Combustion Turbine, Combined Cycle, Reciprocating and Aeroderivative
Demand Side Management - Energy Efficiency and Demand Response

Capacity credit[1]

100% for thermal and energy storage resources
Solar resources begin with a 35% capacity credit in 2021 and decline throughout the RPP
Wind resources begin with a 30% capacity credit in 2021 and decline slightly throughout the RPP

Key assumptions for all scenarios modeled include the following:

Tri-State May 2020 Spring Reset Power Forward Curve
Tri-State May 2020 Spring Reset Gas Forward Curve
Tri-State May 2020 Annual Long Term Load Forecast
Contracts are allowed to expire on their terms
Meet or exceed Renewable Energy/Portfolio Standards
Planned Coal Retirements
- Craig 1 12/31/2025
- Craig 2 9/30/2028
- Craig 3 12/31/2029

Other assumptions Vary by Scenario.

Public Inputs to Tri-State's 2020 IRP

Based on the above information and the Tri-State Summary posted here, we ask that interested parties provide input to Tri-State's 2020 IRP via email at resourceplanning@tristategt.org. This email inbox will be monitored by Tri-State Energy Resource staff from late July 2020 through the end of September 2020. 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.

[1] Capacity credit values are based on a modified Effective Load Carrying Capability study completed by Black & Veatch for Tri-State in June 2020.

for existing and generic resources are as follows:

View the presentation here.

2019 ERP/IRP Meeting cancellation

This to notify stakeholders that the July 2nd ERP/IRP public meeting is cancelled.

Senate Bill 236 which reauthorized the CPUC also included language that caused Tri-State to become jurisdictional under the CPUC for resource planning. It is uncertain how and when the rulemaking will occur to establish the new requirements and timing for Tri-State’s resource planning. Because the new law has been signed, thus establishing the potential for an entirely new process, Tri-State filed with the PUC seeking a variance from the old resource planning rules as we prepare for the new rules. With that, we will cancel our July 2nd ERP/IRP public meeting. We will reengage the public process as soon as we know the schedule that will be developed at the PUC under a rulemaking process. We anticipate the rulemaking will be fast tracked with the new process beginning later in 2019 or early in 2020.

2019 ERP/IRP Update

On May 31, 2019, Tri-State filed a petition with the Colorado Public Utilities Commission requesting that the Commission issue an order extending the deadline for filing Tri-State’s next ERP from October 31, 2019 to December 31, 2020. Additionally, the petition included a request that the Commission issue an order opening a miscellaneous proceeding for the purpose of soliciting input and information concerning electric resource planning for wholesale electric cooperatives and rule proposals consistent with 40-2-134, C.R.S.

This petition was filed and these requests were made as a result of the recently passed Colorado legislation that will impact Tri-State’s Resource Planning processes, including the current ERP process. Tri-State will continue to update stakeholders about its current ERP process and timeline as it receives direction and guidance from the Colorado Public Utilities Commission.

Past 2019 ERP/IRP Public Meetings

Wednesday, March 27, 2019; from 9 a.m. - 4 p.m. at Tri-State Headquarters, 1100 W. 116^th Avenue, Westminster, Colorado 80234. Learn more about this meeting here and download the presentation.

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