California ISO extends Flex Alert for today, 4-9 p.m.
FOLSOM, Calif. – The California Independent System Operator (ISO) issued a statewide Flex Alert, a call for voluntary electricity conservation, for today, Sept. 9, from 4 p.m. to 9 p.m., due to a prolonged heat wave pushing up energy demand and tightening available power supplies.
The ISO also issued an Energy Emergency Alert (EEA) 1, effective today from 4 p.m. to 8 p.m., which signals that supply deficiencies are expected, and market participants are encouraged to offer more energy bids.
With above-normal temperatures continuing in the forecast across much of the state, the power grid operator is expecting high electricity demand, primarily from air conditioning use, and is calling for voluntary conservation steps to help balance supply and demand.
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. During that time, consumers are urged to conserve power by setting thermostats to 78 degrees or higher, if health permits, avoiding use of major appliances and turning off unnecessary lights.
To minimize discomfort and help with grid stability, consumers are also encouraged to pre-cool their homes and use major appliances before 4 p.m., when conservation begins to become most critical.
Reducing energy use during a Flex Alert can help stabilize 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
Flex Alert Conservation Actions
Before 4 p.m.:
- Pre-cool home by setting the thermostat to as low as 72 degrees
- Use major appliances, including:
- Washer and dryer
- Dishwasher
- Oven and stove for pre-cooking and preparing meals
- Adjust blinds and drapes to cover windows
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.
Learn more about emergency notifications. Follow grid conditions in real time at ISO’s Today’s Outlook, download the free ISO Today mobile app, and follow us on Twitter at @California_ISO.
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California ISO | 250 Outcropping Way | Folsom, CA 95630 | www.caiso.com
The California Independent System Operator (ISO) is a nonprofit public benefit corporation focused on the continuous improvement and secure operation of a reliable grid for the benefit of consumers. It provides comprehensive grid planning, and ensures open, nondiscriminatory access to one of the world’s largest networks of high-voltage transmission power lines and operates a $9 billion competitive electricity market.
The ISO is at the forefront of integrating renewable power, storage systems and advanced technologies onto the grid to support state energy policies and decarbonization goals, while keeping reliability and cost effectiveness at the core of its operations and ensuring a sustainable and resilient energy future.
The Western Energy Imbalance Market (WEIM) is a real-time wholesale energy trading market that enables participants anywhere in the West to buy and sell energy when needed. Set to launch in 2026, the Extended Day-Ahead Market (EDAM) extends market operations into the day-ahead timeframe. The Western Energy Markets Governing Body, designed by regional stakeholders, shares authority with the ISO Board of Governors to advance rules specific to participation in the WEIM and the EDAM.