MISO last week said it will begin hunting for solutions to mitigate “significant gaps” between load-modifying resources (LMRs) that clear capacity auctions and what actually shows up to help mitigate emergencies.

The RTO acknowledged during a Resource Adequacy Subcommittee teleconference Wednesday that it had a problem with the amount of LMR-accredited values and what is listed as available to allay demand during summer peak times.

Market Design Adviser Dustin Grethen said that when MISO hit its summer peak in July 2019, 6 GW of LMRs were listed as available, though 11.5 GW cleared the Planning Resource Auction a few months earlier.

Grethen said some of the availability issues result from LMR outages, fear of penalties by overstating load-reducing capability, overly generous LMRs accreditation, voluntary self-deployment or difficulties using the RTO’s availability reporting tool, the MISO Communication System (MCS). Some LMRs that double as emergency demand response enter availability through a separate RTO tool and not the MCS, he said.

Even those reasons cannot explain all the widespread unavailability, Grethen said. He promised MISO would investigate why some LMRs are no-shows after clearing the capacity auction.

Customized Energy Solutions’ Ted Kuhn suggested the grid operator start by checking the MCS’ availability against the metered data LMRs are required to provide.

The LMR availability gap is part of MISO’s ongoing resource availability and need suite of market improvements. The RTO is still gauging which combination of new resource adequacy and capacity market rules it might adopt to reduce the number of maximum-generation emergency events it declares. (See MISO Closer to Seasonal Capacity, Reliability Reqs.)

As part of that, the grid operator will now scrutinize the actual availability of conventional generators and for what they’re accredited. Planning Adviser Davey Lopez said MISO’s planning reserve margin requirement is likely understated because it doesn’t model real-world generation outage scenarios.

Pandemic Still Muddying Forecasts

MISO is still calculating emergency resources’ response during its most recent emergency event on July 7. (See Max Gen Event Managed Efficiently, MISO Says.)

Executive Director of Market Operations Shawn McFarlane said MISO didn’t have to resort to LMRs that day. He said the peak would have been higher had not thunderstorms popped up in the northern part of the footprint.

McFarlane also said the pandemic continues to complicate load forecasting, as air conditioning load is likely skewed to more residential use this year than in others because of customers working from home.

“We think there’s some offsetting things that made it very hard to predict summer peak,” he said.

Despite that, McFarlane called the event “one of the most orderly max gens I’ve seen,” as MISO responded quickly and committed more resources appropriately.

MISO President Clair Moeller said not much has changed in the RTO’s modus operandi after the pandemic’s announcement.

“The risk profile doesn’t seem to be changing much,” Moeller said during an Informational Forum on July 21. “The good news is the operational impacts of the pandemic are manageable … and we don’t expect that to change.”

Moeller said load “crept back up” in July and is now about 5% less than its normal load average.

“We’re still learning how to forecast in this new environment,” he said.