Published on December 1, 2025 8:20 am
Last Updated on December 1, 2025 8:20 am
Some Ameren Illinois (Ameren) customers in central and southern Illinois will receive a credit on their upcoming power bills. The credits are the result of a $38 million settlement Illinois Attorney General Kwame Raoul’s office reached with Dynegy Inc. (Dynegy), a subsidiary of Texas-based Vistra Corporation.
The Federal Energy Regulatory Commission (FERC) approved the settlement in August 2025, resolving 10 years of investigation and litigation by the Attorney General’s office and other parties. It stems from the 2015 electricity capacity auction conducted by the Midcontinent Independent System Operator (MISO), which resulted in an electricity capacity price that was 40 times higher than all other MISO zones and nearly nine times higher than the prior year’s price.
“Dynegy manipulated the market to overcharge electric customers by taking advantage of rules that have already been deemed unjust and unreasonable,” Raoul said. “I am pleased that FERC has finally approved this settlement and that consumers will receive this long-overdue relief.”
Under the settlement, approximately $33.5 million will be refunded to Ameren residential and small commercial customers on Basic Generation Service or Real Time Pricing supply rates in the form of one-time credits to offset their Ameren electricity bill. Consumers can expect to see the credits, which will be based on their energy usage, applied beginning in December.
The Attorney General’s office, along with public interest organization Public Citizen, as well as Southwestern Electric Cooperative and the Illinois Industrial Energy Consumers, filed complaints with FERC in 2015, arguing that the MISO price was unjust, unreasonable and the result of unchecked market power by Dynegy. At the time, Dynegy had recently acquired several Ameren power plants. As a result, Dynegy was able to set the capacity price for central and southern Illinois far above a competitive level because the demand for power in Illinois could not be met without it. FERC partially granted the complaint in 2015 and referred the matter to FERC’s Office of Enforcement that reviews claims of market power. However, FERC dismissed the Office of Enforcement’s 2019 finding that Dynegy had manipulated the market and dismissed the complaints without further investigation.
The United States Court of Appeals reversed FERC’s action and sent the complaint back to FERC for further proceedings to address the “starkly anomalous results” that pushed Illinois capacity charges up from $16.75 to $150.00. In 2024, FERC ordered Dynegy to engage in settlement talks with the Attorney General’s office and other complainants, resulting in the settlement.
In addition to the $33.5 million to Ameren customers, the settlement also calls for $1.14 million to go to Southwest Electric Cooperative, $1.33 million to the Illinois Municipal Electric Agency, and $2 million to members of the Illinois Industrial Energy Consumers. The capacity auction at issue in the settlement sets one of the charges included in consumers’ electricity supply bills. Customers who receive their electricity through suppliers independent of Ameren or through their municipality did not pay the inflated price and are not eligible for the refund.
