June 16, 2021 - FOLSOM, Calif. – With extreme heat expected to break temperature records and linger over much of California and the West for the remainder of the week, the California Independent System Operator (ISO) 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
 Turning off unnecessary lights

If the ISO 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. Consumers can:
 Pre-cool your home or apartment by lowering the thermostat
 Use major appliances, like your dishwasher, and clothes washer and dryer
 Close window coverings to keep your home or apartment cool
 Charge electronic devices
 Charge electric vehicles

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 ISO’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 ISO 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.

To help prepare for the heat and heightened stress on the grid, the ISO declared a grid Restricted Maintenance Operation (RMO) for noon to 10 p.m. for today 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.

To review tips on conserving energy and sign up for notifications, visit FlexAlert.org.

For the most up-to-date information on emergencies, you can follow us on Twitter at @California_ISO. More updates on System Conditions Bulletins will also be available on the News page of the California ISO website.

And please click here to learn more about System Alerts, Warnings and Emergencies. You can follow grid conditions in real time at ISO’s Today’s Outlook, or download the free ISO Today mobile app.
Source: CA. ISO