MISO met NERC’s frequency response requirement for 2015, although performance was not as good as a year earlier, adviser Terry Bilke told an April 13 Reliability Subcommittee meeting.
The RTO’s estimated annual frequency response was -475 MW/0.1 Hz in 2015, complying with its obligation of -211 MW/0.1 Hz under NERC’s frequency response standard (BAL-003-1).
Still, results from local balancing authorities were not as good as in 2014. “I was kind of hoping we’d see incremental improvement year-over-year,” Bilke said, adding that the decline was small enough to be attributed to sampling error.
“We’re still okay,” RSC chair Tony Jankowski said. “But there’s nothing that says we’re going to be OK except for past performance. And obviously, that’s [no] guarantee.”
Data for the first quarter of this year showed that more than 400 generators provided no frequency response in the first quarter, while about 100 plants were determined to be harming MISO performance. Fewer than 200 generators rated an “OK” response, with a small number classified with “theoretical perfect performance.”
“Interestingly, one of the best performers was a wind farm,” Bilke said.
That assessment comes as MISO stakeholders are being asked to respond to FERC’s Feb. 18 Notice of Inquiry, which seeks comment on whether RTO pro forma interconnection agreements should be changed to require all new generation be capable of providing frequency response (RM16-6).
Jankowski said the language in the notice indicates that FERC does not recognize all the factors at play.
“From the market’s perspective, I don’t think we have any indication that a generator is a frequency response generator or not, or a good performing generator or not,” he said. “So to have any sort of expectation that we don’t have enough [frequency response] because the market clears wrong, I don’t buy that. There isn’t a constraint for frequency response.”
MISO thinks frequency response should be compulsory for new generation and voluntary for all existing generation, Bilke said. He added that if reliability declines in light of a changing resource mix, FERC should revisit the issue.
Comments on FERC’s notice are due April 25. Jankowski urged the RSC to be “proactive” in making suggestions on frequency response incentives and penalties through local balancing authorities.
“Nothing precludes us from doing this today,” he said.
March Incident Breaks 3-Month Perfect Score on Commitment Performance
Last month’s sole “unacceptable” rating for real-time unit commitment performance — occurring March 22 — was attributed to an operator’s mistake.
“We had a unit that was left on in an operator error,” Steve Swan, MISO senior manager of dispatch and balance, said during a monthly operations update. “They misread the runtime. It’s been addressed.”
March otherwise contained all “excellent” daily performance ratings, receiving an overall score of 2.9 — just shy of “perfect,” but breaking a trend of perfect 3 rankings in peak hour unit commitment since December.
The month had no minimum or maximum generation alerts or warnings nor any tie-line errors lasting longer than 15 minutes.
Swan also reported that -45,308 MW was added to MISO’s inadvertent interchange balance in January, bringing the running total of imbalances since 2009 to -749,641 MW.
By the end of this month, MISO expects to complete two bilateral inadvertent interchange paybacks, where two balancing authorities swap under-generation for over-generation. Swan said MISO is also performing “internal data mining” to investigate why the footprintwide balance continues to be negative.
Seams Quarterly Report Released
MISO has released its latest quarterly report on seams issues.
“We historically haven’t gotten a lot of review on [the report],” said Ron Arness, Seams Management Working Group liaison. He noted that, although feedback is light, stakeholders continue to request the report every year.
— Amanda Durish Cook
