The California Independent System Operator late on Sept. 7 issued a statewide Flex Alert for the following day from 4 p.m. to 9 p.m. The call for conservation was because of expected high heat across the West and soaring demand from increased air conditioners on Wednesday. CAISO also directed a restriction on routine maintenance operations from noon to 9 p.m. “to avoid taking grid assets offline,” it stated. Mid-day Wednesday, the Flex Alert was extended into Thursday because of persistent heat. Peak demand on Sept. 8  was 43,936 MW and the forecast peak for Sept. 9 was 43,750 MW.