State power officials declare flex alert

Peak electricity demand today is forecast to be 47,125 megawatts, still under the all-time record of 50,270 megawatts in 2006. Even so, the California Independent System Operator, which manages the state's electric grid, is advising everyone to reduce energy use, especially between 11 a.m. and 6 p.m. Demand is expected to drop off a bit on Friday and then even further over the weekend when most businesses are closed. The heat wave should peak out today and tomorrow, with some noticeable relief by Sunday. From the Desert Sun:

Edison was "doing OK for now" with power reserves, Edison spokesman David Song said, but that could change with unforeseen circumstances, such as a wildfire. Equipment working overtime is the worry right now. "When you get into day three, day four, day five of a prolonged heat wave, you see people using more electricity around the clock," he said. "When we don't give equipment time to rest, that's when we have problems." Edison has increased the number of crews available to respond to potential outages throughout the weekend.

From DWP:

Despite the high temperatures, the LADWP system has functioned well and power outages have been minimal, however hot weather can lead to outages- and for a variety of reasons. The heat not only leads to more people operate their air conditioners all at once but also causes other appliances to work harder in order to perform. This puts strain and stress on electrical infrastructure and can overburden power lines, transformers and other equipment, causing them to fail. It can also trigger substation circuit breakers or other electrical equipment that is designed to protect the system to shut down automatically before serious damge occurs.