CAISO endures another heat wave by the skin of its teeth

Early September brought a late-summer heat wave to California that resulted in record peak demand and severely stressed the state’s power grid. Just like the mid-August 2020 heat wave, the key hours of concern aligned with peak net demand (gross demand less renewable generation), which occurred in the evening hours as solar generation waned, but demand remained strong. However, unlike 2020, this time CAISO managed to avert rolling blackouts despite the record demand and reduced hydro generation. This success is the result of several factors: the growth of battery storage, new and expanded demand response programs, and the continued flexibility provided by CAISO’s critical gas-fired fleet. As California looks to future heat waves, there are reasons for both optimism and pessimism, and proactive planning will be essential to keeping cool.