California escaped rolling blackouts during the July heat wave thanks to hard work and good luck, as well as excellent hydroelectric conditions and overtime work from aging power plants, said participants at a California Energy Commission meeting Aug. 29 in Sacramento. The state’s energy system did surprisingly well, but we might not be so lucky next year, warned Scott Matthews of the commission.

But although California’s electricity system “responded surprisingly well” during the record-breaking weather, which boosted electricity use to a record of 50,270 megawatts, it cannot count on the same cushions in a future energy crunch, said Scott Matthews of the state Energy Commission. He noted that 138 deaths were attributed to the heat, and urged better preparation for future events.

“We’ve experienced the limits of our risk tolerance,” he warned at a commission hearing that aimed to draw lessons from the recent heat wave.

Attendees were warned that this heat wave might not be the last. Although many speakers described conditions as “unprecedented,” few predicted that they would not recur — especially as greenhouse gas accumulates in the atmosphere.