Electric meter
An electric meter. Photo via Pixabay

Searing heat across the Southwest and soaring electricity demand from air-conditioners this week are prompting grid operators in California and Texas to warn consumers about energy conservation to avoid outages.

Peak temperatures were forecast to reach 115 degrees in interior California through the week, according to the state’s electric grid operator, which warned the biggest supply deficit could occur on Thursday after the sun goes down and solar power is no longer available.

With temperatures soaring in San Diego and beyond, a Flex Alert calling on residents to voluntary cut their power use will be in effect Thursday evening in hopes of reducing strain on the state’s power grid.

According to the California Independent System Operator, which manages the state’s power grid, the Flex Alert will be in effect from 5 p.m. to 10 p.m. Thursday.

A Flex Alert is a call for voluntary energy conservation, essentially a plea for residents across the state to cut their power use to reduce overall demand and lower the risk of outages.

Around midday Wednesday, Cal-ISO projected that it would have adequate energy supplies through Thursday, although it urged residents “to remain vigilant” in case demand suddenly increased and threatened the availability of power reserves.

Shortly after 2 p.m., Cal-ISO announced plans for the Flex Alert.

According to Cal-ISO, residents are urged to take steps prior to the alert taking effect, such as pre-cooling their homes, using major appliances and closing window coverings to preserve cool air indoors. Once the alert takes effect, residents should set their thermostats to 78 degrees or higher, avoid using major appliances and turn off all unnecessary lights.

Temperatures in other states, including Arizona and Utah, were in line for several more days of sweltering heat even before the start of summer, which officially starts on Sunday.

Grid operators in Texas and California both dealt with rotating outages over the last year to avoid widespread collapses of their power systems — California due to the heat in August 2020 and Texas in February 2021 after a deep freeze that left millions without heat – some for days.

Cal-ISO projected demand plus reserves required in case something goes wrong with a generating plant or transmission line, would exceed power supplies for several days this week.

The ISO forecast peak demand in California would rise from 40,858 megawatts on Wednesday to 43,323 on Thursday, compared with the all-time peak of 50,270 in July 2006. One hundred megawatts typically powers around 20,000 homes on a summer day.

On Wednesday, solar power was providing about 30% of California ISO’s supply, and the grid warned that it would be unlikely to be able to rely on additional supplies from other states due to the extreme heat hitting much of the Western United States.

The ISO was currently getting 13% of its power from other states. The ISO has said it expects to have about 50,734 MW of supply available this summer, but some of that comes from solar.

The Electric Reliability Council of Texas, which operates most of that state’s power system, projected electric demand would break the June record set on Monday in coming days.

ERCOT said demand reached 69,943 megawatts on Monday and is expected to reach 70,391 on June 17. The state’s grid is separate from the rest of the country, so it can draw only small amounts of power from other grids to offset greater-than-normal demand.

City News Service and Reuters contributed to this article.