Power grid operator predicts high heat, energy demand this holiday weekend

The California Independent System Operator (ISO) has issued a statewide Flex Alert, a call for voluntary electricity conservation, beginning Saturday, September 5 and extending through Monday, September 7 from 3:00 p.m. to 9:00 p.m.

Labor Day weekend temperatures are forecast 10-20 degrees above normal for California, and the power grid operator is predicting an increase in electricity demand, primarily from air conditioning use. Overnight temperatures statewide are projected to be at least 10 degrees higher than normal, which doesn’t allow infrastructure to cool down.

High heat is also predicted throughout the West for the weekend, which can limit the ISO’s ability to import energy to serve demand.

Consumers can actively help by shifting energy use to morning and nighttime hours. Conservation can lower demand and avoid further actions, including outages, and lessen the duration of possible power interruptions. For example, consumer conservation efforts during a heat wave on Aug. 17 and 18 were key to preventing expected power outages.

Consumers are urged to conserve electricity when the grid is most stressed in the afternoons and evenings, when temperatures remain high and solar production is falling due to the sun setting.

The ISO recognizes that reducing energy use during the hot time of the day is a hardship, especially for those working from home or for families with children schooling at home. However, if a large enough number of consumers conserve even in small ways, they can help grid operators avoid more serious system emergencies. Between 3:00 p.m. and 9:00 p.m., the ISO is urging consumers to:

• Set air conditioning thermostats to 78 degrees, if health permits.
• Defer use of major appliances.
• Turn off unnecessary lights.
• Unplug unused electrical devices.
• Close blinds and drapes.
• Use fans when possible.
• Limit time the refrigerator door is open.

Consumers can also take steps to prepare for the Flex Alert by doing the following before 3:00 p.m.:

• “Pre-cool” their homes, or lower air conditioning thermostats.
• Charge electric vehicles.
• Charge mobile devices and laptops.
• Run dishwashers, washing machines and other major appliances.
• Set pool pumps to run in the early morning or late at night.

For information on Flex Alerts, to get more electricity conservation tips, and to sign up for conservation alerts, visit the ISO’s Flex Alert website. Visit the ISO’s News page for more information on the heat wave’s impacts on grid operations, and to learn more about alerts, warnings and emergency notices.

For updates on grid operations, follow us on Twitter at @California_ISO or @FlexAlert, or monitor system conditions in real time at ISO’s Today’s Outlook.