MISO appears likely to use a system support resource (SSR) designation to keep a Wisconsin coal plant operating past its planned suspension date unless stakeholders come up with a viable alternative.
During a West Technical Study Task Force teleconference Friday, MISO’s Huaitao Zhang said staff uncovered unresolved thermal overloading and steady state voltage issues on 12 constraints if Manitowoc Public Utilities’ Lakefront 9 unit is allowed to begin its suspension as planned on Feb. 1, 2023. The 63-MW coal-fired unit began commercial operations in 2006.
The grid operator will collect stakeholders’ input on alternative mitigation plans to the SSR agreement through Nov. 18. However, it says alternative solutions are scarce because there are too few resources nearby to employ generation redispatch, no new generation projects in the works, no contracted demand side management programs in the area, and zero available transmission reconfiguration options.
“Lakefront 9 will need to be designated as an SSR unless feasible alternatives are identified and can be implemented prior to the planned suspension date,” Zhang said.
Staff noted that some transmission projects on the horizon will improve system performance enough to terminate the SSR. The earliest is expected to be in service by early April 2023, not soon enough to avoid an SSR.
Clean Grid Alliance’s Natalie McIntire asked whether MISO studied using synchronous condensers as a potential interim solution or considered converting the plant itself into a synchronous condenser. Zhang said MISO hadn’t contemplated that.
Stakeholders on the teleconference did not offer any other alternatives.
The RTO uses SSR agreements as a last-resort measure to keep generators online past their retirement dates and sustain system reliability.
Zhang told McIntire that MISO’s proposal to require retiring or suspending generation to give a year’s notice instead of the currently required six months will allow staff to solicit solutions earlier in the process, giving them more time to identify feasible alternatives. (See MISO Stays Course on Sharpening Generation Retirement Studies.)
A Lakefront 9 SSR designation will be MISO’s second within a year. It received FERC permission last month to establish a yearlong SSR agreement for Ameren Missouri’s 1.2-GW Rush Island coal plant. (See FERC: Rush Island Plant’s Extension Essential to MISO Reliability.)
Since its inception, MISO has approved about 200 retirement notices and issued a dozen SSR agreements.
