Some Ameren Illinois customers to get bill credit in settlement over market manipulation with Dynegy

A recent announcement by Attorney General Kwame Raoul has revealed that certain Ameren Illinois customers in central and southern Illinois will soon see a credit on their upcoming power bills. This credit is the outcome of a $38 million settlement that Raoul’s office negotiated with Dynegy Inc., a subsidiary of Vistra Corporation based in Texas. The settlement, approved by the Federal Energy Regulatory Commission (FERC) in August 2025, concluded a decade-long investigation and legal battle involving the Attorney General’s office and other parties.

The settlement originated from a 2015 electricity capacity auction conducted by the Midcontinent Independent System Operator (MISO), resulting in an electricity capacity price that was significantly higher in central and southern Illinois compared to other MISO zones and the previous year. Under the terms of the settlement, approximately $33.5 million will be returned 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 bills. These credits, tailored to individual energy usage, are set to appear on bills starting in December.

The legal battle began in 2015 when the Attorney General’s office, along with Public Citizen, Southwestern Electric Cooperative, and the Illinois Industrial Energy Consumers, filed complaints with FERC alleging that Dynegy’s market power manipulation led to the unjust and unreasonable MISO price increase. This manipulation was facilitated by Dynegy’s recent acquisition of several Ameren power plants, enabling them to set prices at uncompetitive levels due to the high power demand in Illinois. Despite FERC initially granting a portion of the complaint and referring the matter for further review, it dismissed the Office of Enforcement’s subsequent findings in 2019. However, the United States Court of Appeals intervened, overturning FERC’s decision and urging further investigation into the market manipulation that caused the Illinois capacity charges to surge from $16.75 to $150.00.

In response to the court’s directive, FERC ordered Dynegy to engage in settlement discussions with the Attorney General’s office and other complainants, eventually culminating in the $38 million settlement. This agreement ensures that impacted Ameren Illinois customers will receive financial relief through bill credits, marking a significant development in the ongoing efforts to address market manipulations that adversely affect consumers.