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ICC orders cost benefit analysis of Ameren’s membership in MISO or other RTO

On July 22, the Illinois Commerce Commission accepted the recommendations of an ICC Staff Report directing Ameren Illinois to study the benefits and costs of continued participation in the Midcontinent Independent System Operator (MISO), a regional transmission organization, versus participation in PJM Interconnection, another RTO.

“MISO’s most recent capacity auction for the June 1, 2022-May 31, 2023 delivery year fell short of meeting resource adequacy requirements to cover load plus required reserves for Zone 4, putting upward pressure on wholesale pricing and increasing utility bills for central and southern Illinois customers,” said ICC Chairman Carrie Zalewski. “The ICC feels it is appropriate to explore whether membership in MISO continues to provide net benefits to Ameren Illinois’ electricity customers.”

In 1997, the Illinois General Assembly enacted the Electric Service Customer Choice and Rate Relief Law of 1997, significantly restructuring Illinois electric industry and opening Illinois energy markets to competition. The law allowed certain Illinois electric utilities owning and controlling transmission or providing transmission services in Illinois to choose membership in a regional transmission organization without oversight by the state. Section 16-126 of the Public Utilities Act ceased to be effective on July 1, 2022, and the State – and this presumably includes the Commission – is no longer prevented by statute from prohibiting an electric utility from membership in the RTO of its choosing,

MISO manages the electricity transmission system in 15 states and one Canadian Province.

“Illinois is the only fully competitive state in the MISO region. Utilities within the other states remain vertically integrated, combining functions and resources for the generation, transmission and distribution of electric power and energy. It is our assertion that this study is warranted to determine whether or not MISO remains a good fit for Ameren Illinois,” said ICC Commissioner Michael T. Carrigan.

According to the Order, the study should examine a period of no less than five and no more than 10 years from the beginning June 1, 2024. The study should examine the costs and benefits to ratepayers including but not limited to, consideration of reliability, resource adequacy, resiliency, affordability, equity, and the impact on the environment, and the general health, safety, and welfare of the People of Illinois. Ameren Illinois is entitled to maintain a level of independence and control of the analysis. Ameren has up to one year to complete and file the study with the ICC. Stakeholders will then be afforded 30 days to offer comment on the report.

To read the Staff Report and Commission’s Final Order within Docket No. 22-0485 click here.

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