San Francisco, Aug 18 (IANS): California Governor Gavin Newsom signed an emergency proclamation on to free up energy capacity due to an ongoing heatwave in US state.

The proclamation, signed on Monday, temporarily allows some energy users and utilities to use backup energy sources to relieve pressure on the grid during peak times during the energy emergency, reports Xinhua news agency.

State officials worked aggressively over the weekend to bring more energy resources online, according to a statement from Newsom's office.

State officials noted that California's power grid is about 4,400 megawatts short of the energy needed to provide uninterrupted power service.

Local authorities declared a statewide Stage 3 Electrical Emergency over the weekend, initiating phased outages throughout for the first time since 2001.

In an effort to prevent or limit power outages during the heat wave, the California Independent System Operator issued a statewide Flex Alert, a call for voluntary electricity conservation, beginning Sunday and extending through Wednesday.

The Flex Alerts are in effect from 3 p.m. to 10 p.m. each day.

"Record-breaking heat is straining supplies; consumers should plan for potential outages," the agency tweeted on Sunday.

Officials urged California residents to refrain from major appliance use, turn off unnecessary lights and appliances, and set their thermostat to 25.5 degrees Celsius or higher between 3 to 10 p.m.

Excessive heat warnings were issued by the National Weather Service on August 15 and will be in effect till Wednesday for most of Southern California.

Temperatures in California's Death Valley 54.4 degrees Celsius on Sunday afternoon, the highest temperature recorded in the country since 1913, according to the National Weather Service.