SAN DIEGO — Due to high temperatures and high energy demand, the California Independent System Operator Corporation (ISO) issued a statewide Flex Alert calling for voluntary electricity conservation from 4 p.m. to 10 p.m. Tuesday.

Consumers are urged to conserve electricity especially during the afternoon when air conditioners typically are at peak use. Consumers can help avoid power interruptions by turning off all unnecessary lights, using major appliances before 4 p.m. and after 10 p.m., and setting air conditioners to 78 degrees or higher.

RELATED: Excessive heat warning issued for Tuesday and Wednesday for San Diego region

Because of widespread heat, the ISO anticipates energy demand reaching a peak of 42,800 megawatts (MW) this evening. Also, two units with a total generation of 1,260 MW are offline due to mechanical failures. The Flex Alert is being called in response to the high electricity demand and the reduced generation.

The ISO earlier in the day issued a Restricted Maintenance Operations (RMO), which requires generators and transmission owners to postpone scheduled maintenance, to keep grid assets available for use.

Flex Alert conservation could reduce the risk of further emergency measures, including rotating power outages.

The ISO’s service territory serves about 80 percent of California’s electricity consumers and a small portion of Nevada.

For more electricity conservation tips, visit the ISO’s Flex Alert website at http://www.flexalert.org/save-energy.

Conservation Tips

• Set thermostat at 78° or higher and turn off, if away

• Cool with fans and draw drapes

• Turn off unnecessary lights and appliances

• Use major appliances in morning or late evening

Learn more: http://www.flexalert.org  (Available in Spanish and Vietnamese)