By Tom Kleckner
DES MOINES, Iowa — SPP ended eight days of conservative operations last week, just in time to meet near-record demand in its 14-state footprint.
The RTO declared the alert, a level down from an energy emergency, on July 10, when it projected an above-normal number of primarily forced outages and a drop in wind production. Normal operations resumed on Wednesday.
SPP was already without 13 GW of non-variable resources when it declared the alert. Those outages peaked at slightly more than 14 GW on July 13, before finally falling to less than 10 GW on Thursday.
“At one point, 45% of our generation was unavailable to us through outages or derates,” Operations Vice President Bruce Rew told the Markets and Operations Policy Committee on July 16. He said outages were slightly less than 8 GW a year ago on July 13.
Rew said SPP was predicting a more normal wind production of 12 to 13 GW through the end of last week. Forecasters pretty much nailed their prediction.
“Less than 5 GW is a low wind day for us anymore,” he said.
Fortunately, the alert ended just as SPP was expecting to set new records for peak demand. Demand fell short Wednesday to Friday, though on Friday it came within 30 MW of the all-time mark of 50.6 GW, set in July 2016.
It was the sixth time the RTO has called for conservative operations this year, more than it did all last year. The first two alerts were called in February and March as a result of normal cold weather events. SPP has since issued alerts on May 29, June 4 and July 1 over what staff called “uncertainty factors.”
“What’s the weather forecast? Potential generation? Certainty of load?” Rew said. “We’re seeing outages extending a little longer than normal.”
Asked if SPP’s criteria for declaring conservative operations have changed, C.J. Brown, director of system operations, said no.
“We have gotten better at what we’re looking at from a certainty perspective,” he said.
Given the number of conservation alerts called this year, which have totaled 25 days, the MOPC asked SPP to further evaluate this year’s events and bring back a recommended policy and/or process improvement to October’s regular meeting. Members asked for more detailed information on the outages and the discrepancies between real-time operating capacity and assumed planned capacity, and to clarify the RTO’s current must-offer requirements.
