California Independent System Operator (ISO) declared a statewide Stage 3 Electrical Emergency Friday due to high heat causing an increased electricity demand statewide.
CAISO explained that a Stage 3 Emergency is declared when the demand for power is greater than the available supply.
As a result of the emergency status, rolling blackouts will be implemented to maintain grid stability. These blackouts are expected to last about one hour each, according to Southern California Edison and Pacific Gas and Electric.
The Stage 3 Emergency declaration was called after extreme heat drove up electricity demand across California, causing the ISO to dip into its operating reserves in order to cover the demand.
California ISO said it is working closely with California utilities and neighboring power systems to manage strain on the grid and to restore the power grid to full capacity.
As portions of the grid are restored, CAISO said local utilities will restore power in a coordinated fashion.
Although a Stage 3 Emergency is a significant inconvenience to those affected by rotating power outages, CAISO said that controlled outages are necessary to manage an emergency rather than let the power demand cause a widespread and more prolonged blackout.
CAISO said the Stage 3 Emergency status is set to expire at 11:59 p.m. Friday night.
For more information on California's power capacity status, warnings and emergencies, click here.