By Amanda Durish Cook

CARMEL, Ind. — MISO’s Independent Market Monitor has a different opinion of the RTO’s summer supply picture three weeks into the season.

Although MISO predicts a 70% chance that it will declare an emergency to call on load-modifying resources (LMRs) this summer, it said its base case shows a 19% reserve margin, with 149 GW of resources on hand to cover a 125-GW projected peak. Its planning reserve margin is 16.8%. (See MISO Foresees Summer Emergency, LMR Use.)

But Monitor David Patton said that while his base case of MISO’s capacity picture also shows a more than 2% excess beyond the planning reserve margin, a more realistic scenario including outages shows a 12.2% margin and an even lower 8.3% margin when accounting for resources that are unavailable to cover emergencies because of their long notification times.

Patton first shared his concerns at the June Board Week in Traverse City, Mich. (See Emergencies Prompt MISO to Re-examine LMR Protocols.) He expanded on them during a Market Subcommittee meeting Thursday, saying, “The way in which we calculate these margins aren’t as accurate as they could be.”

Patton said some hot, high-demand days this summer show margins dipping as low as 2%.

“These margins would raise concerns for some RTOs, but MISO has the unique advantage of having huge import capacity in many directions. … It’s a powerful shock absorber in terms of reliability,” Patton said.

“Our intention is not to scare anybody,” he added, saying he would be concerned if MISO’s footprint were more isolated, like New York’s or New England’s.

MISO staff said that while they don’t dispute the results of the Monitor’s analysis, they haven’t calculated their own additional summer scenarios to compare against it. However, they pointed out that their base case calculations and the Monitor’s were about equivalent.

Patton has called for changes to “an accumulation of rules that aren’t optimal.” He said MISO should carry reserves on the regional dispatch transfer limit on transmission between MISO Midwest and South to temper regional emergency conditions. The suggestion is one of Patton’s State of the Market recommendations this year. (See MISO Monitor Poses 6 New Market Recommendations.)

“It’d be a win-win for the joint parties and MISO,” Patton said. The joint parties are neighboring transmission systems Southern Co., Tennessee Valley Authority, Associated Electric Cooperative Inc., Louisville Gas and Electric, Kentucky Utilities and PowerSouth Energy Cooperative.

Patton wants more transparency around MISO’s decision-making when emergencies are declared and clearer emergency declaration protocols.

“These regional emergencies just began at the end of 2017, beginning of 2018. So, you have [control room] operators exercising a lot of discretion. It’s important to think about what triggers these emergencies,” Patton said.

“There’s nothing written down on what they’re supposed to be doing and how they’re supposed to be weighing these factors. … It should be clear how those factors should be weighed and processed. … We should write down what these triggers are.”

But he also praised MISO operators for taking relatively few out-of-market actions when compared to other RTOs/ISOs. MISO appropriately keeps its out-of-market actions confined to emergency situations, Patton said.

Extended Outages and the Capacity Auction

Patton has continued his criticism of MISO’s capacity auction availability requirements, which he said are too generous.

“We approved and cleared a unit that’s going to be on planned outage for the entire planning year,” Patton said at the June Market Subcommittee meeting, referring to a large generator in Michigan. MISO as a rule does not divulge which generators have taken outages.

“We’ve seen a number of units cleared that won’t be available over the summer peak” over multiple auctions, Patton continued at last week’s meeting.

Had MISO not counted the Michigan generator on extended outage as available in the 2019/20 planning year, Patton said, Michigan’s Zone 7 would have cleared near the $240/MW-day cost of new entry.

“That $24/MW-day is not representative,” Patton said of Zone 7’s auction actual clearing price. (See Most MISO Zones Clear at $3/MW-day in 2019/20 PRA.)

“Zone 7, as we sit here right now, is incapable of meeting its local clearing requirement,” argued the Coalition of Midwest Power Producers’ Mark Volpe at Wednesday’s Resource Adequacy Subcommittee meeting. He said MISO should immediately work with stakeholders to remedy the situation by creating some availability requirements.

“This is about reliability,” Volpe argued. “Resource adequacy in MISO is broken. This should not be permitted to persist.”

MISO Director of Resource Adequacy Coordination Laura Rauch said any new availability requirements should be worked through carefully to avoid unintended consequences.

RASC Chair Chris Plante said “it doesn’t seem right” for MISO to fully accredit a resource that’s on a planned outage for the entire year.

“We completely agree in concept; we’re looking at the potential unintended impacts [of a solution] and how likely it is this will occur again in the next planning year,” Rauch said.

MISO staff said they will provide the RASC a timeline for when new availability requirements could be implemented.