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All MPSC workgroup meetings are being conducted via teleconference. Remote access information for upcoming meetings is available on our calendar of events.
Public Act 235 establishes a statewide energy storage target of 2,500 MW. By Dec. 31, 2029, IOUs will need to file petitions for approvals related to the storage target and Alternative Electric Suppliers will need to file plans for how they will comply with the target. Investor-Owned Utilities (IOUs) are required to begin filing annual storage reports no later than Dec. 31, 2024. Public Act 235 also directs the Commission to complete a study on long-term and multi-day energy storage systems by February 27, 2025.
On February 8, 2024, the Commission initiated Case No. U-21571 to undertake the work required to develop the storage targets and provide guidance on the required annual storage reports. Staff was also directed to complete a study on long-duration and multi-day energy storage systems as required by Public Act 235. Additional information regarding Energy Storage Planning can be found on the Resource Planning Website.
Implementation Status: Complete
Lead Staff: Jon DeCooman
On February 8, 2024, the Commission issued an Order in Case No. U-21571 issuing guidance for Public Act 235 of 2023, Sections 11(1)-(9) and 103.
The Commission also directed rate-regulated utilities to file individual energy storage reports in accordance with the Commission guidance in U-21571.
On January 23rd, 2025, the Commission issued an Order in Case No. U-21571 adopting Staff’s straw proposal, with modifications as necessary, for the calculation methodology for utilities and alternative electric suppliers to determine their proportional share of the minimum statewide energy storage target.
Staff has completed its study on long-duration and multi-day energy storage systems, and it has been filed to the docket for Case No. U-21571. It has also been provided on this page below.
Annual energy storage reports from individual rate-regulated utilities are required to be filed in each utility's most recently approved IRP docket, in accordance with the Commission guidance in U-21571.
Compliance with the minimum statewide energy storage target established under PA 235 requires annual recalculation of each LSE's proportional share of the target, calculated based on an average of the previous 5-years of peak load information as established in the Commission approved methodology in Case No. U-21571. Commission Staff recalculates the individual compliance targets for LSEs annually, as directed in the Commission's order in Case No. U-21571, and files the updated calculation in the most recent open docket for LSE's demonstration filings under MCL 460.6w. Links to Staff's calculations are posted below:
Case No. U-21775: 2025 Statewide Energy Storage Calculation
Staff's Storage Target Straw Proposal
Study of Long-Duration and Multi-Day Energy Storage
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