By Amanda Durish Cook

MISO is currently accepting proposals for a transmission or generation solution to offset reliability issues caused by the planned suspension of a DTE Energy coal-fired plant near Detroit, Mich.

The RTO hopes stakeholder-submitted proposals will prevent the need to create a future system support resource (SSR) agreement for Unit 9 of the 520-MW Trenton Channel Power Plant, in operation since 1968. DTE closed Units 7 and 8 at the plant early last year.

The company plans to shutter the remaining plant in June 2023, but in modeling for 2022, MISO found the shutdown could provoke multiple thermal overload and voltage violation issues that cannot be resolved by generation redispatch or new operating guides.

DTE has said the plant will resume operations in mid-2025, but MISO no longer models a return date in suspension studies, contending suspended generation rarely returns. (See FERC OKs New MISO Retirement Process.)

MISO has so far received seven suggested solutions involving transmission upgrades, including submissions from DTE Energy and ITC, although only one solution has been formally submitted to the RTO’s Transmission Expansion Plan (MTEP) for study and modeling. Solutions must be put before the MTEP process before consideration, and the RTO said solutions will be studied in the MTEP 19 cycle.

MISO will also accept new generation solutions to address issues caused by the retirement, but during an Oct. 22 special conference call, staff said new generation proposals must be submitted through the interconnection queue for consideration and study. The generation queue doesn’t currently contain a project that can mitigate issues from a Trenton suspension. MISO staff said a generation solution may require a Trenton SSR designation to keep the plant online until the new generation comes online.