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California, Texas grid operators respond to soaring temperatures, resulting stress on supplies

Power grid operators in California and Texas this week responded to soaring temperatures and the resulting spike in power demand through a number of steps. The California Independent System Operator (CAISO) called for the deferral of scheduled maintenance on generators or transmission lines, if possible, while the Electric Reliability Council of Texas (ERCOT) issued a call for energy conservation at the start of the week.

With extreme heat expected to break temperature records and linger over much of California and the West for the remainder of the week, CAISO on June 15 said that it is asking consumers to be prepared to conserve energy to help avoid the possibility of rotating power outages.

Those steps would include setting thermostats to 78 degrees or higher, if health permits, avoiding use of major appliances and turning off unnecessary lights.

CAISO said that if it issues a Flex Alert calling for voluntary conservation between the hours of 4 p.m. to 9 p.m. on Wednesday and possibly Thursday, consumers would be encouraged to take other steps to manage their electricity usage to maintain comfort prior to an alert taking effect.

The grid operator said that an abnormally strong ridge of heat is forecast to bring temperatures as high as 115 degrees to the California interior that could last until the weekend. “Because of the extreme heat and nighttime lows expected to cool off only between 78 and 83 degrees, the state’s electric grid will be straining to meet evening demand when air conditioners are in heavy use and solar energy generation is waning.”

The CAISO’s own projections currently show electricity demand exceeding power supplies that are guaranteed under the state’s Resource Adequacy (RA) requirements for several days this week. The biggest deficit is projected for Thursday between 8 p.m. and 9 p.m. when demand is forecasted to be 43,261 megawatts (MW), including required contingency reserves, or 3,374 MW more than expected to be available under the RA program.

The CAISO noted it has steps it can take to close that gap, including demand response programs that utilities use to provide incentives for customers to conserve, but one regularly relied on asset -- imported electricity from neighboring states -- could be affected.

“That’s because the National Weather Service is now forecasting that extreme heat is expected to engulf much of the Western United States. Triple-digit heat is forecast from the deserts east of Los Angeles all the way north to the Canadian border, resulting in tight energy supplies over a large geographic area,” CAISO said.

To help prepare for the heat and heightened stress on the grid, CAISO declared a grid Restricted Maintenance Operation for noon to 10 p.m. from June 15 through Friday. The directive cautions energy generators that all available resources are needed, and to defer scheduled maintenance on generators or transmission lines, if possible.

If a Flex Alert is called this week, consumer conservation can make a big difference, as it has during past heat waves when such concerted action helped avoid grid emergencies, including rotating outages, the grid operator said.


Meanwhile, the Electric Reliability Council of Texas (ERCOT) on June 15 said that when it issued a call for conservation on Monday, Texans responded strongly by reducing electric demand during the late afternoon. ERCOT continues to encourage Texans to conserve power each afternoon during the peak hours of 3 to 7 p.m. through this Friday.

“The grid is operating exactly as it was designed and intended. The issuance of conservation notices is a common practice and prevents ERCOT from entering emergency conditions. Conservation efforts combined with the changes in procedures and processes implemented by ERCOT and the PUC following the winter storm prevented the possibility of rotating outages yesterday and ensured that no Texans lost power,” ERCOT said.

ERCOT said it has been leveraging every resource at its disposal, including activating all available generating units to help serve customer demand before calling for conservation. Approximately 1,200 MW of power was regained overnight Monday when some repairs were completed.

On June 14, ERCOT set a new June record for electricity demand. Based on preliminary data, the new record is 69,943 MW, which exceeds the 2018 June record by approximately 820 MW.

Power plant owners continue repairs of unexpected equipment failures, “and ERCOT is using all the tools in its toolbox to maintain reliability in the face of potential record-setting electricity demand,” it said.

“All of our local plants are up and running, and virtually all of them are at full capacity,” said Rudy Garza, Chief Customer & Stakeholder Engagement Officer for San Antonio, Texas public power utility CPS Energy, on June 14. “We’re asking our other customers to help even further by conserving energy to support the grid.”

CPS Energy also provided a set of actions that residential and business customers can take to conserve energy.

Austin, Texas public power utility Austin Energy on June 14 noted that its staff works year-round to maintain and monitor a diverse mix of power generation plants to ensure peak performance during extreme conditions. The utility also employs various demand response programs that help lower electric use during strained grid conditions.

In 2020, Austin Energy rolled out Weekly Electricity Update and High Bill Alert emails providing customers with electricity usage details and energy-efficiency tips. These emails help customers learn more about their electricity usage patterns and trends. They also contain insights and tips to help customers lower their electricity usage and save on their bills.

The Weekly Electricity Updates email compares energy usage rates from week to week, while the High Bill Alerts email lets customers know when their usage is higher than compared to the same monthly cycle from the previous year.

These notifications are a free and optional service automatically provided to eligible City of Austin customers with an advanced meter at their location and an email address on file. Customers can unsubscribe at any time.

Austin Energy this week also provided tips for Austin Energy customers to help conserve energy.