CAISO’s Department of Market Monitoring on Dec. 12 reported that the ISO saw “one of the highest demand peaks” in recent years, at 48,353 MW on Sept. 5 — but still well short of the record of 52,061 MW in 2022.
Speaking at the ISO’s Market Performance and Planning Forum, Guillermo Bautista Alderete, the department’s director of market analysis and forecasting, highlighted that the peak was also higher than the California Energy Commission’s forecast of 47,160 MW.
Annual CAISO demand typically peaks in July to mid-September. Besides the 2022 record, this year’s figure marked the highest peak load since Sept. 1, 2017, when demand rose to 50,116 MW. It was also an increase of about 8.6% over last year’s 44,534 MW on Aug. 16.
Monthly resource adequacy showings, which came out to be a little over 53,000 MW, slightly increased from 2023 and were sufficient to cover CAISO’s load plus operating reserves in September. That was “the reason why we didn’t have any tight supply conditions to the extent that we have observed in previous years,” Alderete said.
He also noted that there was a significant decrease in gas-fired generation coupled with a significant increase in storage resources: 3.6 GW compared to 5.5 GW.
“That aligns with the present trend that we have seen of quick penetration of storage resources exceeding the 10,000-[MW] mark sometime in 2024,” Alderete said.
Despite what Alderete described as a relatively moderate September, the ISO did support a “reasonable level” of wheel-through transactions, peaking at just over 500 MW.
September also saw the highest participation in the Assistance Energy Transfer (AET) program since its inception in 2023. Nine balancing authority areas opted into the program, accumulating approximately $720,000 in AET surcharges in August and September.
