Illinois storage auction lands 600 MW against 3 GW mandate

Illinois closed its first battery storage procurement with contracts for 600 MW — less than two-thirds of the 1 GW target the legislature set for the initial round of a program that must deliver 3 GW by the end of 2030.

The Illinois Power Agency ran the auction-type proceeding in August, culminating on Aug. 26, under the Clean and Reliable Grid Affordability Act signed in January. The state sought 588 MW in ComEd's northern Illinois territory. It got one project: a single 80 MW battery. In Ameren Illinois territory, which covers most of the state, three developers' bids were selected to supply 520 MW.

The state entered the auction with 102 MW of installed storage, according to energy data firm Cleanview. Even the partial result multiplies that base several times over.

What went wrong in the north?

Advocates point at the PJM Interconnection, the regional grid operator serving ComEd's territory and parts of 13 states. Long interconnection delays have discouraged developers from committing to batteries that must be operational by 2030.

Brett Sproul, who leads regulatory work in Illinois for Advanced Energy United, a national industry group whose members include renewable and storage companies, said multiple developers could build in Illinois by 2030, "however because of the interconnection queue at PJM there's a lot of uncertainty" about whether projects could start storing power by the deadline.

"That uncertainty led to some cold feet," he said.

The mismatch is geographic. The Ameren territory sits in the Midcontinent Independent System Operator grid, where connection timelines proved more workable and bids flowed.

How the incentive works

Illinois uses "indexed storage credits." Developers bid the revenue level they need; if wholesale prices fall short, utilities make up the difference with customer funds, and if prices run higher, developers pay the excess back.

The model can cap a developer's upside. It also guarantees a floor, which matters in a restructured market where generators compete for contracts rather than recovering costs through regulated rates.

James Gignac, Midwest policy director at the Union of Concerned Scientists, said the mechanism appears to be working "given that we had multiple projects bidding into the procurement." He called the outcome "a strong start" that indicates "there is interest in developing energy storage in Illinois."

What changes before 2027?

The Illinois Power Agency is collecting developer feedback through Oct. 28. Two constraints shaped the first round, and both could move.

• Eligibility. Only stand-alone storage projects could bid. Solar-plus-storage may qualify in the next round — a pairing Sproul called "a really … thriving market now."
• Grid allocation. The agency asked whether it should shift a larger share of the 3 GW goal onto the MISO grid, where the first procurement performed better.

The legislature set strict rules for round one to force speed. The agency has more flexibility to set terms for the 2027 and 2028 procurements.

How does Illinois compare?

The national picture frames the gap. U.S. grid storage grew from 4.7 GW in 2022 to more than 50 GW today, per federal data. Texas holds over 18 GW and California over 16. Indiana leads the Midwest at 587 MW — more than five times Illinois' installed base.

New York offers the closest parallel: the same 3 GW by 2030 target, 288 MW installed, and a September procurement that secured 950 MW using the same indexed-credit mechanism. Two of the four companies selected in Illinois are New York-based.

Massachusetts shows the timeline risk. It launched a storage initiative in 2015 and set a target in 2018, yet progress stayed slow until the past two years, with legislation in 2024 and an executive order this year to push deployment.

Jen Walling, CEO of the Illinois Environmental Council, which represents more than 150 environmental organizations, said: "I'm just absolutely delighted we're procuring battery storage. The more we can invest in deployment of renewables and storage, the more likely it is we can reduce pollution for Illinois communities."

The Oct. 28 feedback deadline, and the terms the agency writes for 2027, will decide whether the 3 GW mandate stays a mandate or becomes a shortfall.