Heavy use is continuing to take a physical toll on California electric power generation units. The California Independent System Operator declared a Stage 1 power emergency Friday, signaling reserves had fallen below 7%.
The ISO blamed mechanical failure at two southern California generating units which cut available generating capacity by 500 Mw and continued high demand on the system. On Thursday, the ISO declared a more serious Stage 2 alert, signaling reserves were below 5%, after the loss of 400 Mw caused by mechanical failure at a northern California plant.
Friday is the seventh day of high temperatures in the state. The ISO said peak load is expected to reach 42,600 Mw by late afternoon.
California has teetered on the edge of rolling blackouts since the beginning of the week as the ISO has scrambled to find extra power. Emergency alerts have been accompanied by so-called "no touch" days that limit or prohibit any maintenance work at power plants unless specifically authorized by the ISO.
Postponing the work only heightens the risk of mechanical failure and other plant breakdowns, expert say. But the state has few other options no matter how unpalatable the strategy and prospect of a sudden loss of generating capacity. Surrounding states have cut exports to California to meet their own demand and no new generating capacity has been approved and built in the state for a decade.
The series of power emergencies which have led businesses to work in the dark and send employees home, plus skyrocketing power prices in San Diego Gas & Electric Co.'s service territory continues to create a crisis atmosphere in the state.