Emergency demand response produced 85% to 97% of promised reductions during the July heat wave, according to an analysis presented to the Market Implementation Committee last week.
No results are available from the September heat wave because Curtailment Service Providers have 45 days after an event to provide their data to PJM. The lag means charges for DR deployments won’t show up on bills for months after the triggering events.
“It makes it very difficult to understand what went on,” said Barry Trayers, representing Citigroup Energy Inc. “If you look back years later you’ll say `the September event wasn’t so bad.’ No, because [the charge] ends up in January.”
Dave Pratzon, who represents generators, said the results suggested “a little bit of response fatigue” in the ATSI zone, where DR was dispatched three times in July and twice in September.
ATSI’s DR performance fell from 95% on July 15 to 91% July 16 and 87% on July 18. “This may be our first little bit of data on what response to repeated calls will look like,” Pratzon said.
PJM says it expects to call on DR increasingly in the future, leading some to predict performance will suffer. (See Cool Reception for DR “Fatigue” Study)
