IPA, ICC, IEPA Issue the 2025 Resource Adequacy Study

In accordance with Section 9.15(o) of the Illinois Environmental Protection Act, the Illinois Power Agency (IPA), the Illinois Commerce Commission (ICC), and the Illinois Environmental Protection Agency (IEPA) have released their joint 2025 Resource Adequacy Study (RA Study) assessing the current and projected electric resource adequacy and reliability throughout Illinois across the period ahead.

About the Resource Adequacy Study

This analysis draws upon extensive research, modeling, and data review, including:

• Information from Regional Transmission Organizations (MISO and PJM)
• Utility-provided data from ComEd and Ameren
• Public data sources and reports
• Proprietary modeling conducted by Energy and Environment Economics (E3) on behalf of the Agencies
• Stakeholder feedback gathered through two virtual workshops (June 16 and October 8, 2025), each followed by a request for written feedback responding to targeted topical and policy questions

The resultant Resource Adequacy Study includes three core components:

Each can be accessed using the links above. Key takeaways from the RA Study include the following:

• There are resource adequacy challenges in PJM and MISO which are likely to affect the costs and reliability of electricity supply for Illinois businesses and consumers.
• There are pathways for Illinois to achieve its climate goals in the electricity sector while ensuring a reliable electric grid, using available commercialized technologies.
• Illinois has the responsibility, authority, and policy tools to conduct planning, identify solutions, and support implementing actions to address these challenges.

Upcoming Releases and Stakeholder Engagement

In addition to the release of the comprehensive RA Study Report, the Agencies will also publish a comprehensive set of data files on December 22, providing the underlying inputs, assumptions, and modeling datasets used to produce the Resource Adequacy Study results. These materials will be available on the Resource Adequacy Study web page, organized into a dedicated section for stakeholders to access and download.

The Agencies will host a stakeholder workshop in late January 2026 presenting the findings of the Resource Adequacy Study. That workshop will also outline next steps in support of the next phases of the study as defined in Section 9.15(o) of the IEPA Act, including the process and timeline associated with the development of a mitigation plan. Following the workshop, the Agencies will open a new request for stakeholder feedback.

Additionally, recently-passed Senate Bill 25 directs the Illinois Commerce Commission (in consultation with the IPA and other agencies) to develop a comprehensive Integrated Resource Plan (IRP) that "addresses any resource adequacy challenges in the 5 years immediately following approval of the plan, while also taking into account the 10 years following the plan." To facilitate solutions, the ICC may "order changes to existing programs, direct specific actions within existing programs including the authorization to support the expansion of an existing program." Because the activities associated with the RA Study and the IRP are so closely linked, the Resource Adequacy Study provides a foundational analysis that will feed into and support IRP development throughout 2026.

To learn more, visit the Resource Adequacy Study web page on the IPA website and subscribe to the Resource Adequacy Study email distribution list.