California ISO issues flex alert to decrease peak energy demand due to heat wave

The California Independent System Operator (CAISO) issued a call for voluntary electricity conservation, this week through Wednesday, Aug. 19.

This Flex Alert is due to a record-breaking heatwave in California and across the western states, which is causing a strain on supplies. CAISO said consumers should be prepared for likely rolling outages during the late afternoons and early evenings through Wednesday as there is not enough energy to meet the high amounts of demand.

CAISO officials said consumers can help decrease the demand by shifting energy use to morning and evening hours and conserving as much energy as possible during the late afternoon and evening hours. This will help lessen the likelihood of outages.

Consumers are urged to lower energy use during the most critical time of the day, which is 3 p.m. to 10 p.m. This can be done by setting air conditioning thermostats to 78 degrees, if health permits, deferring the use of major appliances, turning off unnecessary lights, unplugging unused electrical devices, closing the blinds and drapes, using fans when possible, and limiting the time the refrigerator door is open.

Doing certain things before 3 p.m. can help immensely. This means pre-cooling homes before 3 p.m. with AC set to 72 degrees, charging electric vehicles, charging mobile devices and laptops, running dishwashers, washing machines and other major appliances, and setting pool pumps to run in the early morning or late at night.

CAISO – which oversees the operation of California’s bulk electric power system, transmission lines, and electricity market generated and transmitted by its member utilities – issued a Stage 3 Electrical Emergency at 6:28 p.m. on Saturday, Aug. 15, due to increased electricity demand. It caused the unexpected loss of a 470-megawatt (MW) power plant and nearly 1,000 MW of wind power. The load was ordered back online 20 minutes later at 6:48 p.m., as wind resources increased.