For the fourth day in a row, the California Independent System Operator declared a Stage 2 emergency Thursday after the loss of 400 Mw caused by mechanical failure at a northern California generator. The alert, signaling electrical reserves have fallen below 5%, is in effect until 8 p.m. PST.
The California ISO said it will attempt to maintain stability of the transmission system without activating voluntary load management programs. However, the ISO said it may implement interruptible programs if reserves dip to lower levels. Interruptible customers, mainly commercial and industrial users, receive a reduced rate in exchange for a commitment to come off line when asked to do so for reliability purposes.
A Stage One Emergency, urging Californians to conserve as much energy as possible, was called at 11 a.m. Peak demand on the statewide electrical grid was expected to reach 43,605 Mw by late afternoon today. Several areas of the West are still contending with a 6-day heat wave.
California has teetered on the edge of rolling blackouts since the beginning of the week. 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 have created a crisis atmosphere in the state. The political fallout is mounting. The electric power crisis and how to respond to it promise to top lawmakers' agenda when they reconvene next week.