Why a text warning could have helped California keep the lights on

Officials say a cell phone emergency call yesterday played a critical role in helping prevent power outages during an extreme heat wave in California. Local residents apparently sprang into action within minutes of receiving a text urging them to save energy.

A remarkably severe and prolonged heat wave has put increasing strain on the state’s electrical grid since last week. Record-shattering temperatures in the triple digits have skyrocketed the demand for air conditioning power.

On Tuesday, demand reached a highest point ever for the Golden State at 52,061 megawatts, according to grid operator California Independent System Operator (CAISO). CAISO issued a Level 3 Power Emergency Alert, the highest alert, at 5:17 PM that night. It indicated that rotating power outages could be imminent with the power supply stretched so thin.

Shortly after, at 5:45 p.m., the emergency services governor (Cal OES) says it issued the cell phone warning. “Save energy now to protect public health and safety. Extreme heat strains the state’s energy grid. Power outages may occur unless you take action. Turn off or reduce non-essential power if health permits, now until 9 p.m.,” the text read. The message was also sent in Spanish.

Within minutes of the alarm going off, there was a sharp drop in power demand. Between 5:50 and 5:55, it dropped by about 1,200 megawatts.

Sure, CAISO data shows that demand started falling earlier in the night — around the time the Level 3 alarm went off. But it started to fall more dramatically after the cell phone alarm reached people.

At 8:00 PM, CAISO declared the Level 3 severe energy emergency warning over. “Consumer retention played a huge role in protecting the reliability of the power grid. Thanks, California!” the tweeted.

The Governor’s Office was quick to tout the text messages as a success. “As a result of this action, the California Independent System Operation (CaISO) saw an immediate and significant drop in energy consumption, providing some relief to the state’s electrical grid,” Cal OES said in a press release yesterday.

The state managed to narrowly avoid widespread power outages. But tens of thousands of customers, mostly in Northern California, still dropped out at one point yesterday. Today, Californians are in their eighth straight day under a flex alert asking them to voluntarily curb their energy use from 4pm to 9pm when power demand typically peaks.

Yesterday wasn’t the first time emergency SMS alerts have helped officials ease pressure on the power grid. New York City saw something similar in June 2021. Local officials there sent a similar text to residents asking them to conserve energy during a brutal heat wave, and power demand quickly plummeted.

The California text messages were part of a nationwide system of “wireless emergency alerts.” Those alerts can be sent by federal, state or local officials to warn of national emergencies, natural disasters or orange alerts for missing children.