Flex alert: Californians urged to conserve power on Wednesday FacebookTwitterEmail This file photograph shows high voltage power lines sit over homes seen from Terrace Drive in El Cerrito, Calif. Friday, September 25, 2020.Jessica Christian/The Chronicle California’s electric grid operator is urging residents to voluntarily conserve energy on Wednesday from 4 p.m. to 9 p.m. amid higher-than-normal temperatures expected in portions of interior Northern California and due to “tight supplies across the West,” officials said. The California Independent System Operator announced its flex alert on Tuesday afternoon, saying that it predicts an increase of “electricity demand, primarily from air conditioning use.” That rise in electricity use can strain the state’s power supply and can “make electricity supplies tight,” California ISO officials said.