California heat wave causes demand spike and rolling blackouts


Record high temperates have been sweeping across California causing utility companies to institute rolling blackouts affecting more than 410,000 homes and businesses over the past weekend.

California Independent System Operator (ISO) ordered the first rolling outages in nearly 20 years on Friday, August 14, when it directed utilities around the state to shed their power loads.

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Demand management

The state’s three biggest utilities — Pacific Gas & Electric, Southern California Edison and San Diego Gas and Electric decreased power output by 1,000MW in response to the increased demand.

Blackouts continued into Saturday evening after a 470-megawatt power plant unexpectedly went offline, with utility companies cutting electricity to 130,000 people in southern California and 220,000 people in the Central Coast and Central Valley areas.

According to the National Weather Service, temperatures in the Central Valley climbed to above 110 Fahrenheit (43 Celcius), with temperatures forecast to continue into the high 80’s this coming week.

A statement from utility Pacific Gas and Electric Company stated that: “Based on current forecasts for electricity supply and demand, the state’s electric grid operator, the California Independent System Operator (CAISO), has communicated to Pacific Gas and Electric Company (PG&E) that the utility does not need to employ rotating power outages in the early to late evening Sunday.

“All customers in portions of San Francisco, San Mateo and Contra Costa counties, who were previously notified via automated calls, will not be impacted by rotating power outages.

“PG&E has been on standby throughout the day, opening its Emergency Operations Center to be ready to execute potential rotating outages at the request of the CAISO. PG&E teams will continue to coordinate with the CAISO as the heatwave extends into next week. The CAISO oversees the larger power grid and balances energy demand with supply.”

With the heatwave expected to continue until Wednesday, PG&E customers are urged to restrict power usage where possible by employing the following measures:

  • Raise the thermostat
  • Use a ceiling fan
  • Cover windows
  • Limit the opening of refrigerators
  • Clean clothes and dishes early