December saw unexceptional load and higher energy prices, MISO said in a monthly operations report.

The grid operator reported an average load of 73 GW and a peak of almost 89 GW on Dec. 26. Load registered lower than last December’s 75-GW average and 91-GW peak.

MISO said higher fuel prices drove real-time LMPs to an average $36.50/MWh, up sharply from the previous December’s average of $24/MWh. Day-ahead prices averaged a little more than $37/MWh.

Coal and natural gas-fired generation sat atop the month’s fuel mix, each serving about 30% of load. Wind and nuclear generation contributed about 18% apiece.

The grid operator had an average 40 GW of generation unavailable daily because of planned and unplanned outages and derates. Most of the 14 GW in daily unplanned outages came from coal and gas units.

MISO’s Central region — Michigan, Wisconsin, most of Indiana and Illinois, and eastern Missouri — averaged 37 GW of load. MISO’s North region — Minnesota, Iowa, North Dakota, northern South Dakota and a sliver of eastern Montana — averaged an 18-GW load. MISO South also averaged 18 GW of load.

The Central region remains the heaviest user of coal generation as it supplied about 50% of the region’s real-time fuel mix in December. The North region was able to draw on a 48% share of wind generation, while the South used a 60% natural gas and 30% nuclear fuel mix.

Unsurprisingly, the month contained an all-time wind generation record, with wind supplying nearly 22 GW of the footprint’s demand on Dec. 12. However, that record was outdone a month later when wind served almost 24 GW on Jan. 18.

MISO collected $139 million in day-ahead market congestion costs during December.

December and January, which MISO considers its riskiest months, are now behind the grid operator without a maximum generation emergency. Cold weather in January forced the RTO to declare a maximum generation warning and send two conservative operations instructions on separate occasions for different parts of the footprint. (See “2 Conservative Ops Declarations in January,” MISO Market Subcommittee Briefs: Jan. 27, 2022.)

MISO told stakeholders before the winter that January would contain the highest risk of an emergency. It also delivered warnings about patchy deliveries of natural gas and coal supplies and generation outages should a cold snap descend on the footprint. (See MISO Sounds Alarm on Potential Winter Fuel Scarcity.)

The grid operator entered this winter with 8 GW of additional generation over last winter, mostly from renewable resources.