Southern California may have to take aggressive conservation steps to avoid electricity shortages should the coming summer be unusually hot, the operator of the state's power grid said Thursday.
The California Independent System Operator, which runs most of the transmission system, reviewed its "summer assessment," which showed that the state as a whole probably has enough electricity supplies for a typical summer.
But a summer heat wave -- affecting all parts of the West from Phoenix to Los Angeles, through the Bay Area and Portland, Ore. -- could leave Southern California with "critically thin operating margins" and a shortfall of as many as 1,700 megawatts, Cal-ISO said.
(One megawatt powers about 750 typical homes.)
The Cal-ISO report, presented jointly with officials of the California Energy Commission and California Public Utilities Commission, is the latest in a series of government agency forecasts aimed at preparing business and residential electricity consumers for periods of peak usage this summer. The reports, released periodically since December, have indicated that Southern California could be short of power in an extremely hot summer.
"If we have adverse conditions and if things get extremely tight, that is the call for conservation," Jim Detmers, Cal-ISO's acting chief operating officer, told reporters.
A growing population means more demand for electricity, but the Southland needs more transmission upgrades and new power plants to meet that demand and maintain adequate reserve margins, said Yakout Mansour, chief executive of Cal-ISO.
Conservation remains the most economical way to deal with surges in demand because it is too costly for utilities and ratepayers to try to build enough power plants and transmission lines to handle short periods of heavy consumption, Mansour said.
State officials need to act quickly to put conservation programs back in the public spotlight now that memories of the energy crisis of 2000-01 have begun to fade, said V. John White, director of the Center for Energy Efficiency and Renewable Technology in Sacramento.
"We should be doing this for its own sake because it saves money and saves pollution," he said. "But we should also do it because it's the best way we have left to make sure that we keep the lights on."
Demand for power in California is growing nearly 4% a year; last summer the peak demand record for the state set in 1999 was broken seven times, hitting 45,597 megawatts on Sept. 8.
Although a transmission corridor connecting Northern and Southern California has been expanded, congestion remains on the corridor farther south, limiting the delivery of surplus electricity from north to south.
California has added more power plants in the north than in the south, but demand growth has been greater in Southern California.
Detmers said that the Southern California corridor would get a short-term upgrade of 400 megawatts of capacity in time for summer but that more steps would be needed by a year later.
Cal-ISO and state utilities offer conservation and energy efficiency programs, including voluntary efforts for homes and businesses; emergency steps that cut off "interruptible" commercial and industrial users; and rolling blackouts.
California also may be able to draw on some extra power supplies in the Pacific Northwest this summer, Detmers said.