California's grid operator urges customers to conserve power today

California's grid operator urged residents to conserve power Monday evening as electricity flow is limited to some western states with a wildfire burning out of control in Oregon.

The California Independent System Operator (CAISO) said transmission lines from Oregon are still threatened due to the fast-growing Bootleg Fire. That coupled with continued hot temperatures in California could strain the power grid. The operator issued a Flex Alert on Monday from 4 to 9 p.m. asking for voluntary conservation.

"Californians who conserve energy this afternoon and evening will help stabilize the state’s electric grid and help respond to the uncertainty caused by the heat and the Oregon fire," CAISO said in a statement.

Californians adhered to Flex Alerts issued for Friday and Saturday, drastically reduced their electricity usage, which allowed the grid operator to avoid or limit possible rotating power outages.

The Bootleg Fire more than tripled in size over the weekend to more than 150,000 acres. The blaze caused transmission lines to trip off on Friday and again Saturday, limiting electricity flow from the Pacific Northwest to California and other states. Power supplies to the CAISO’s service territory, which covers about 80 percent of the state, have been reduced by as much as 3,500 megawatts because of the fire.