MISO intends to adjust the time it allows itself to retroactively correct market-pricing errors, stakeholders learned during a Market Subcommittee meeting Thursday.
The RTO’s markets can experience two types of pricing errors: implementation errors and continuing errors. Market-implementation errors are meant to be remedied near the operating day, with corrections made in time to be used in settlements. Continuing errors, on the other hand, are those discovered after settlement and could require up to two years of resettlements “from the date of MISO’s formal acknowledgement.”
MISO will seek FERC permission to impose a two-week limit on implementation errors and a one-year resettlement timeframe for continuing errors that begins ticking when the grid operator acknowledges the error in writing. Staff’s Daric Moenter said the RTO intends to file tariff changes in the third quarter for commission approval.
Under the proposal, implementation errors will be “identified, investigated and corrected” within two weeks. If they’re not discovered in time to be remedied within the two-week window, they will be subject to corrective settlements through the continuing error process, provided the pricing error meets a threshold of $100,000 or 0.5% of gross market activity per affected operating day.
“The recommended changes ensure that price accuracy is as important as certainty and permanency,” Moenter said.
Laura Rauch, senior director of transmission planning, said MISO is trying to strike a balance between correcting significant pricing errors and not spending “thousands to chase pennies.”
As an example, she said it would take millions of dollars of staff hours to make corrections two years back in addressing a daily settlement error.
Moenter said staff hope to avoid spending “an ordinate amount of staff time” on insignificant pricing errors. He said going back two years to reprice errors in the day-ahead and real-time systems can quickly become burdensome.
WPPI Energy’s Valy Goepfrich said she didn’t see any problems with the existing repricing policy and said she didn’t understand why MISO proposed the changes.
Stakeholders have said that during messy weather events, MISO employees probably don’t have time within the two weeks to review pricing and apply substitution logic to correct errors before they’re settled.
“Everything isn’t always clean and tidy here, and we’ve seen that,” Xcel Energy’s Kari Hassler pointed out in April.
Moenter asked for stakeholder feedback on the repricing proposal through June 10.
