(KGTV) - A high demand for power coupled with high temperatures led the California Independent System Operator Corporation (ISO) to issue a statewide Flex Alert Tuesday.
A Flex Alert is issued when the electricity grid is “under stress” because of persistent hot temperatures, or generation or transmission outages, according to the ISO.
Although San Diego remained relatively cool, with a high temperature in the 70s, other cities in California were put under heat advisories. Sacramento temperatures topped 100 degrees, while San Francisco reached the 90s.
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Californians were asked to conserve power from 4 p.m. through 10 p.m.
“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,” ISO officials posted online.
San Diego Gas and Electric told 10News it reached out to 160 medium-to-large customers, mainly businesses, and asked them to conserve power between 6 p.m. and 8 p.m.
The ISO reported energy use would reach a peak of 42,800 megawatts Tuesday evening.
Two sources of power were offline due to mechanical failures, according to ISO officials. Generators and transmission owners were also required to postpone maintenance to keep more power available for use.