Illinois Energy Storage RFP Reaches Final Bid Stage for 2026 Procurement

Illinois’ Illinois energy storage RFP reached a key procurement milestone Aug. 12, 2026, as qualified projects faced the deadline for submitting their second-stage proposals in the state’s Summer 2026 Energy Storage Request for Proposals. The milestone moves the competitive procurement closer to final price bids and a September regulatory decision that will determine which storage projects secure contracts.

Under the current official schedule, bidder training is set for Aug. 19, final bids are due Aug. 26 and the Illinois Commerce Commission is scheduled to render a decision on procurement results Sept. 1. Supplier contracts are expected to be fully executed by Sept. 4, subject to revisions in the procurement timetable.

The procurement has entered its final competitive phase

The Illinois Power Agency’s Summer 2026 Energy Storage RFP schedule establishes a multi-stage process rather than allowing bidders to submit a single proposal and price.

The Part 1 proposal window opened July 1, with initial proposals due July 16. Qualified bidders were notified July 30, and the Part 2 window opened July 31.

Aug. 12 marked the Part 2 deadline for proposals other than final bids. The procurement documents require qualified bidders to complete the online Part 2 form, provide bid-assurance collateral and submit supporting materials required by the RFP.

The separate final bid date is Aug. 26.

Qualified projects must satisfy detailed procurement requirements

The illustrative Part 2 proposal materials state that only projects that successfully completed Part 1 and satisfy the Part 2 requirements can proceed as qualified proposals.

Bidders must submit bid-assurance collateral through a pre-bid letter of credit or cash and provide the required project documentation. The procurement administrator warns that improperly modified required forms can render a proposal deficient.

That staged qualification structure allows technical and project requirements to be evaluated before the final competitive pricing stage.

Final prices come later this month

The next scheduled milestone for the Illinois energy storage RFP is bidder training on Aug. 19, followed by the Aug. 26 bid deadline.

After bids are submitted, the procurement administrator and procurement monitor are scheduled to provide a confidential report on the procurement results Aug. 28.

The Illinois Commerce Commission is then scheduled to decide whether to approve the procurement results Sept. 1. Contracts with applicable suppliers are expected to be fully executed Sept. 4.

Those dates remain subject to revision, according to the official procurement schedule.

The RFP is part of Illinois’ expanding storage policy

Illinois is pursuing grid-scale storage as electricity systems accommodate more renewable generation and increasingly variable supply and demand conditions.

Battery storage can charge when electricity is relatively abundant and discharge during periods when grid demand or electricity values are higher. Storage can also provide operating flexibility and other grid services depending on market rules and project design.

The state’s procurement comes amid rapid national growth in battery deployment. The U.S. Energy Information Administration reported earlier this year that developers planned to add 24 GW of utility-scale battery storage nationwide in 2026 after a record 15 GW was added in 2025.

EIA said Texas, California and Arizona represented the majority of planned 2026 battery additions, highlighting the opportunity for states outside the largest storage markets to expand their own fleets.

Winning projects have not yet been selected

The Aug. 12 milestone should not be interpreted as an award announcement. The procurement remains competitive, and final bids have not yet been submitted.

Publicly available procurement materials reviewed by Microgrid Media do not establish which projects will ultimately receive contracts, the final prices those projects will offer or the exact portfolio that the Illinois Commerce Commission will approve.

Those distinctions are particularly important for energy-storage procurements because initial project pipelines can be substantially larger than the capacity ultimately contracted or built.

What happens next

The immediate next step is bidder training Aug. 19. Final bids are then scheduled for Aug. 26, followed by the confidential procurement report Aug. 28.

The most consequential public milestone is expected Sept. 1, when the Illinois Commerce Commission is scheduled to act on the procurement results.

Until that decision is issued, individual project awards and pricing should be treated as unresolved.