The Natural Resources Defense Council says many utilities, including the two largest in Michigan, have been operating their coal-burning plants at a loss for extended periods of time.
That's cost customers money and increasing pollution.
The report found that between 2021 and 2023, coal plants owned by DTE Energy and Consumers Energy lost nearly $20 million compared to the market rate, when lower cost solar, wind and natural gas should have been deployed instead.
The practice also resulted in more carbon dioxide, sulfur dioxide, and nitrogen dioxide pollution.
The report said utility regulators could take steps to reduce the practice; state regulators in particular could disallow utilities from billing customers for electricity produced by coal burning plants at times they shouldn't be in operation.
DTE said it is on the path to end the use of coal by 2032, with a goal of achieving a carbon-neutral future in line with the state’s 100% Clean Energy Standard by 2040.
"The claims in the report lack supporting evidence," the company continued in its statement, "largely ignoring the physical operating characteristics of coal plants. DTE evaluates the economics of all generation, including coal plants, and maximizes customer value within the confines of the MISO market."
The utility added that the Michigan Public Service Commission has determined its power supply cost recovery cases to be "reasonable and prudent."
Consumers Energy said it has been working aggressively to develop a carbon-neutral grid and will close the last three of its coal plants by next summer.
The MPSC said it is aware of the report and said Michigan is among the states most quickly retiring coal plants, "as the cost of coal-fired generation exceeds the costs of power produced through renewable energy resources and natural gas."
"As the report notes, the MPSC issued an order disallowing uneconomic coal generation costs in a recent case involving Indiana Michigan Power Co."
"The commission will continue to monitor generation costs as it works to implement Michigan’s 100% clean energy standard by 2040, enacted in the revamp of the state’s energy laws in 2023," the statement said.
