MISO presided over routine operations in June, with an average 81-GW load and diminished wholesale prices.
Average load was down 3 GW compared to June 2022. MISO’s real-time locational marginal prices fell more dramatically, from about $75/MWh to $28/MWh year over year. Most of the drop was attributed to natural gas prices falling from about $8/MMBtu to $2/MMBtu within the year.
Average daily generation outages also were lower than last June, at about 38 GW instead of 41 GW. MISO operated with a fuel mix of 44% natural gas, 29% coal, 15% nuclear and 9% wind.
The grid operator realized a 3-GW solar peak June 20, when solar generation served 3% of total load at midday.
Heat arrived in the latter half of the month, forcing multiple rounds of conservative operations instructions and MISO’s 111-GW peak on the evening of June 29. The monthly peak was 10 GW short of last June’s peak.
MISO said it will internally review a more than 7% error in its load forecasting for June 29. The grid operator attributed the load estimate error to severe weather in the footprint’s central region that ultimately shaved 10-20 degrees from initial weather forecasts.
So far, summer hasn’t held any emergency procedures for the footprint. MISO managed to avoid a maximum generation emergency last week during a systemwide heatwave. (See MISO Preps for Heat Wave, Anticipates Annual Demand Peak.)
MISO ultimately issued two separate maximum generation alerts for its Midwest region two days before the expansive heatwave intensified July 27 and again July 28. Those followed MISO’s issuance of conservative operations instructions, a hot weather alert and a capacity advisory July 23.
The grid operator said July 25 that it was facing risks from above-normal temperatures and forced generation outages. It had warned that its forecasted high loads could have caused it to come within 500 MW of its operating obligations for July 27.
“With increased risk and uncertainty, it may be necessary for MISO to escalate further based on changing system conditions,” MISO said at the time.
MISO has a hot weather alert in effect for its South region through Aug. 4. Temperatures in the region are expected to be near 100 degrees.
