California seeks energy conservation for 9th day in heat wave

© Reuters. FILE PHOTO: A woman jogs by power lines in Mountain View, California, U.S., August 17, 2022. REUTERS/Carlos Barria/File Photo

(Reuters) - California's power grid urged customers to conserve energy for a ninth day in a row on Thursday as homes and businesses crank up their air conditioners to escape a brutal heat wave lingering over the drought-stricken region since the start of September.

The California Independent System Operator (ISO), grid operator for most of the state, said consumer conservation efforts so far this week have been key to helping the grid avoid rotating outages.

Demand for power in the ISO hit an all-time high on Tuesday while prices for Tuesday and Wednesday hit two-year highs before dropping for Thursday.

The ISO wants consumers to conserve energy during the late afternoon hours when the sun goes down and solar power stops working. Solar has provided about a third of the grid's electricity during the middle of the day but nothing at night.

High temperatures in Sacramento, the state capital, have topped 100 degrees Fahrenheit (37.8 Celsius) every day in September and were forecast to reach a record 111 F on Thursday and 106 F on Friday before the heat wave breaks on Saturday, according to AccuWeather. That compares with the current record of 107 F for Thursday in 1944 and a normal high of 90 F.

The last time the ISO ordered utilities to shed power was for two days in August 2020 when outages affecting about 800,000 homes and businesses lasted anywhere from 15 minutes to about two-1/2 hours.

California's biggest utilities are PG&E (NYSE:PCG) Corp's Pacific Gas and Electric, Edison International (NYSE:EIX)'s Southern California Edison and Sempra Energy (NYSE:SRE)'s San Diego Gas and Electric.

The ISO projected power demand would reach 51,361 megawatts (MW) on Thursday and 48,897 MW on Friday. That compares with the preliminary record of 52,061 MW on Tuesday, which broke the prior all-time high of 50,270 MW in 2006.