MISO said last week it quickly regained control during its first maximum generation emergency July 7 during a lasting heatwave.

“Uncertainty in both load and supply, impacted by COVID-19, created some challenges that I think we successfully managed,” MISO Executive Director of Real-Time Operations Rob Benbow said during a July 30 Reliability Subcommittee meeting.

Since 2016, the RTO has not completed a single year without a maximum generation event, amassing 10 emergency events in four years. However, summertime emergencies are relatively rare for the grid operator, representing only two of the 10 events.

Benbow said MISO needed “abnormal and emergency procedures” from July 1 through July 20 to navigate tight conditions.

The RTO and its members operated under a hot weather alert July 1-10 and a capacity advisory and conservative system operations — where maintenance outages are asked to be put on hold — July 6-10.

MISO declared a maximum generation event July 7 as high temperatures collided with an unusually large number of unavailable generators in the RTO’s North and Central regions. The emergency lasted from about 1:00 to 5:30 p.m. Load peaked at 116 GW, below the 120-GW forecast.

Benbow said MISO anticipated the hot weather and communicated with its members as early as possible.

After the RTO had committed all available resources, almost all of the 600 MW in emergency resources called upon stepped up, he said. MISO also recalled some scheduled transmission outages during the day.

MISO maintained good communication with neighbors PJM, SPP, Tennessee Valley Authority and Southern Co. during the event, Benbow said. The RTO discussed temporarily raising the 2,500-MW MISO South to Midwest regional transfer limit with its southern neighbors, but it ultimately wasn’t necessary.

Following the July 7 event, the RTO again declared a hot weather alert July 16-20 for its Central region.

“Especially the North and Central regions were in the mid-90s for most of early July,” Benbow said.

He noted that MISO would return to the Reliability Subcommittee in August with more information on generation outages and emergency resource performance.

Multiple stakeholders said while the emergency declaration communications to members were clear, it was less clear when MISO terminated its conservative operations and hot weather alerts during July.

Some stakeholders asked if unavailable nuclear generation played a role in the emergency because nuclear plant operators tend to be older and more susceptible to severe COVID-19 infection. Benbow said while one nuclear plant was out during the emergency, he suspected it was “because of mechanical reasons.”

Mild June in MISO

June operations were a different story for the grid operator, with load peaking at just 107 GW on June 30.

June 2020 in the footprint registered at one degree Fahrenheit above NOAA’s 30-year average, according to MISO.

Low natural gas prices also kept prices low during the month.

“The real-time LMP was $18/MWh for the second straight month, a 25% decrease over 2019,” MISO Executive Director of System Operations Renuka Chatterjee reported during a July 21 MISO Informational Forum.

Chatterjee also said load — subdued by the pandemic since mid-March — has gradually begun to rebound. The RTO load bottomed out to about 10% below normal levels during May; the impact has since decreased to about 5%.

“June and July data suggests [that] COVID-19 impact on load and energy is diminishing due to warmer weather, recovering to more historical levels,” Benbow said.

MISO is still using its back-up control center at its Carmel, Ind., headquarters, he said. To date, no operators have tested positive for the novel coronavirus.

Benbow also said its non-core operations employees can now return to MISO offices on a voluntary basis. The RTO currently has no plans to make in-person work mandatory for non-operations staff, but it will likely reevaluate sometime in the fall if the pandemic crisis abates.

Meanwhile, MISO is still rearranging some generation outages after virus-induced barebones work crews caused some utilities to hold off on scheduled spring maintenance outages.

MISO Outage Coordinator Trevor Hines said the RTO is connecting with market participants to discuss rescheduling outages in the fall.

“If you have flexibility to adjust your outage schedule, please reach out to MISO,” he asked members.