ORLANDO, Fla. — MISO said its system encountered “moderate fall weather that produced minimal operating challenges” this year, encountering rough patches only when unseasonably warm weather clashed with the generator maintenance season.
“The beauty of this fall is that it was wholly uneventful,” J.T. Smith, the RTO’s executive director of market operations, told the Board of Directors during a Markets Committee meeting Tuesday.
Demand averaged 71 GW during the season, peaking at 107 GW. MISO averaged 72 GW during the fall of 2021 and had a 98-GW peak.
The grid operator has gone more than a year without a maximum generation event. In October, it was forced to issue a capacity advisory and order conservative operations for its South region when maintenance outages dovetailed with a late heat wave. It also issued a capacity advisory and hot weather alert in September for its Central region.
MISO’s generation fleet, much of it aging thermal resources, averaged about 53 GW of daily derates and planned and unplanned during the season. That was in line with last year’s average of 54 GW. The grid operator has a little more than 160 GW in accredited capacity.
MISO set a record for wind output at 24.2 GW in late, blowing past the earlier mark of 23.6 GW recorded in January.
Smith said staff continues to work on its unit commitment process by improving its optimal dispatch calculator. Independent Market Monitor David Patton has said MISO often made resource commitments that appear unnecessary during the year.
The grid operator is anticipating a 102-GW system peak in January under typical winter conditions. That would jump to 109 GW should an arctic blast descend on the footprint. (See MISO: Diminished Emergency Possibilities this Winter.)
A January cold snap may have MISO “leaning on imports or walking into” emergency steps to call up its load-modifying resources, Smith said. He predicted active winter storm patterns in Michigan, Indiana, Ohio and Illinois that could potentially ice over transmission lines and wind turbines.
Smith said staff continues to monitor developments on the nation’s railway system, even after Congress averted a rail strike last week. He said coal production and deliveries remain strained and that an unstable supply chain of chemicals to scrub emissions is also a point of concern.
Director Nancy Lange observed that she wasn’t hearing members’ anxiety or the urgent fuel supply warnings MISO issued ahead of last winter.
“We are seeing less conservation of coal right now, indicating [operators] are more comfortable with their current supplies,” Smith said. “I’m not as concerned as I was last year over procurement.”
Patton agreed that coal conservation is ebbing across the footprint as winter approaches, signaling confidence in fuel supplies.
During a Technology Committee meeting Tuesday, staff reported they encountered a software defect in September that caused a process to fail within its energy management system. They said the defect was caused by too many input constraints, exceeding system capacity, and MISO was forced to transfer critical systems to its backup data center. The vendor managing the software has since come up with a patch to increase the software’s constraint capacity, the RTO said.
