FOLSOM, Calif. – With historic heat bearing down on California for the next several days and energy demand approaching record levels, the California Independent System Operator (ISO) is stepping up its call for consumers to lower electricity use in the afternoons and evenings to avoid outages.
“Starting tomorrow, this multi-day event is going to get much more intense,” said ISO President and CEO Elliot Mainzer. “We are facing a load forecast of 48,817 megawatts and energy deficits between 2,000 and 4,000 megawatts for Monday, resulting in the highest likelihood of rotating outages we have seen so far this summer.
“Because of the increasingly extreme conditons, we will need significant additional consumer demand reductions during the hours of 4 p.m. to 10 p.m. on Monday and access to all the emergency tools that the state and utilities have established for an extreme event like this one. We thank electricity consumers for their sustained effort to help us maintain reliability during these very difficult conditions.”
The ISO has issued a statewide Flex Alert, its sixth straight day calling for consumers to cut their electricity use, tomorrow from 4 p.m. to 10 p.m., when they are urged to set thermostats to 78 degrees or higher, avoid using major appliances, and turn off all unnecessary lights. A Flex Alert is also in effect today from 4 p.m. to 9 p.m.
The extra hour of reduced energy use is needed tomorrow because of projected market deficiencies through 10 p.m.
Additional calls for reducing energy consumption are expected as the state endures record-breaking temperatures lasting at least through Friday. The heat wave is historic for both its temperatures and its duration.
Heat advisories and excessive heat warnings are in place across the West, with daytime high temperatures forecast to be 10-20 degrees above normal.
Electricity customers’ actions to cut their demand have already resulted in an estimated 600 to 700-megawatt savings in recent days and are expected to be even more important and impactful through the next several days.
Power grid conditions are expected to be strained this evening, with a potential for supply shortfalls. However, Monday and Tuesday are still projected to be the most challenging days yet, with the highest temperatures forecast on Tuesday and projected electricity demand of 50,099 megawatts (MW). For a look at historical demand, see the ISO’s Peak Load History report.
The peak load yesterday was 44,123 MW, and the forecast for today is 45,776 MW.
Grid operators are closely monitoring wildfires for potential threats to generators and transmission wires, and fire officials have warned that more fires could break out in the coming days, due to the prolonged high heat and dry conditions.
Several generators are already out of service, making supplies tighter.
Consumer and commercial demand response, including Flex Alerts, has been helping to extend tight resources at critical hours so far this week.
The Flex Alert is scheduled between 4 p.m. and 9 p.m., when the grid is most stressed from higher demand and less solar energy on the system..
Consumers are also encouraged to pre-cool their homes and use major appliances before 4 p.m., when solar supplies are abundant. Cooling homes in advance minimizes discomfort during the Flex Alert and helps to stabilize the grid.
Reducing energy use during a Flex Alert can help protect the power grid during tight supply conditions and prevent further emergency measures, including rotating power outages.
For information on Flex Alerts, and to find more electricity conservation tips, visit FlexAlert.org.
Tips before a Flex Alert:
- Pre-cool home by setting the thermostat to as low as 72 degrees
- Use major appliances:
- Washer and dryer
- Oven and stove for pre-cooking and preparing meals
- Adjust blinds and drapes to cover windows
Tips during a Flex Alert from 4 p.m. to 9 p.m.:
- Set thermostat to 78 degrees or higher, if health permits
- Avoid using major appliances
- Turn off all unnecessary lights
A Flex Alert is issued by the ISO when the electricity grid is under stress because of generation or transmission outages, or from persistent hot temperatures.
Follow developing grid conditions at the ISO’s News webpage, under the System Conditions Bulletin, or follow us on Twitter at @California_ISO.
Click here to learn more about System Alerts, Warnings and Emergencies. Follow grid conditions in real time at ISO’s Today’s Outlook, or download the free ISO Today mobile app.