California Heat Wave: Conserve Power During Extreme Weather, State Urges Residents

Updated 6 p.m. Thursday, June 17

As demand for air conditioning spikes amid a statewide siege of triple-digit heat, the agency that runs California’s electrical grid has extended an alert that asks consumers to conserve power.

The Flex Alert from the California Independent System Operator calls on residents to make a special effort to minimize electricity use between 5 p.m. and 10 p.m. Thursday and from 6 p.m. to 9 p.m. Friday.

In a media briefing Wednesday, the grid manager said it called the alert after forecasting a relatively small shortfall in power available to the grid as electricity demand peaks Thursday afternoon. With another hot day looming Friday, the agency decided to extend the alert into a second day.

The Flex Alert is a statewide request for consumers to take a series of steps Thursday and Friday evenings:

• Set thermostats to 78 degrees or higher, if health permits
• Avoid using major appliances
• Turn off all unnecessary lights
• Use fans for cooling and unplug unused electrical items

California ISO also suggests that consumers can take several steps to prepare before the alert takes effect, including:

• "Precool" homes and apartments by lowering air conditioner thermostat settings
• Use major appliances, like your dishwasher, and clothes washer and dryer
• Close window coverings to keep your home or apartment cool
• Charge electric vehicles and electronic devices before the alert takes effect

“We certainly know from experience, including last August and September, that Californians can make a huge difference in helping maintain overall grid stability by taking these very straight-forward and pragmatic steps to help conserve,” California ISO President and CEO Elliot Mainzer said during the media briefing.

California ISO had forecasted Thursday's power demand will peak at about 43,000 megawatts between 6 p.m. and 7 p.m. — an estimate that declined during the day as cool conditions prevailed in coastal Southern California. Friday's forecast peak is a bit lower -- about 41,400 megawatts.

Those estimates 10% to 12% less than the highest level of demand last Aug. 14, when the grid's reserve capacity was exhausted and California ISO directed the state's biggest electrical utilities to initiate rotating power outages.

The agency said several factors make it unlikely that the state will see a return of rolling blackouts Thursday.

Among them: More natural gas-fired generation capacity within California; an increased level of battery storage for power generated by renewable sources like solar and wind; greater availability of power from the Pacific Northwest, which is largely unaffected by the current heat wave and thus has more electricity to export to California; and relatively mild temperatures along the California coast, which is reducing statewide demand.

The heat wave that's stressing the power grid is forecast to bring triple-digit temperatures to much of the state through Saturday.

By early Thursday afternoon, the mercury had soared past the 110 mark in the state's southeastern desert region, with Palm Springs hitting 123 degrees by 4 p.m., shattering the record of 115 for June 17, set in 2017, and tying its all-time record.

In the Bay Area, Travis Air Force Base, outside Fairfield in Solano County, reported a record-setting 110 degrees. The old record, 103, was set in 2012.