With the heat on and the state?s economy growing, Monday?s Stage One electricity emergency is bringing into focus the question of whether economic growth may soon strain the state?s grid and require more emphasis on energy conservation this summer. ?We?ve seen high demand based on the heat, but we think we?re seeing economic growth play a role too, particularly in Southern California,? said Gregg Fishman, spokesperson for the California Independent System Operator (CAISO). California has added 243,000 jobs over the past year, and growth is expected to continue, according to Jack Kyser, chief economist for the Los Angeles County Economic Development Corporation. Many of the jobs are in industries?such as motion picture and television production and tourism?that use a lot of electricity. In addition, he said, the technology sector is starting to rebound. ?Southern California is the strongest part of the state,? although the Bay Area?s economy is also beginning to improve, Kyser said. ?You?re going to see heavier [electricity] demand.? With a hot summer shaping up, ?definitely there?s a concern? about electricity supply. In 2003, Kyser noted, the greater Los Angeles region added some 40 million square feet of industrial, office, commercial, and warehouse space, all of which must be powered. While underlying growth in demand is an emerging concern, it was a confluence of factors that strained the system early this week, said Paul Kline, spokesperson for Southern California Edison, which asked its customers to conserve power for the second time in March. The company also shut off power briefly during a heat wave March 8 after the Path 15 transmission line became overloaded. On March 29, temperatures soared into the mid-90s in Southern California?s sprawling inland valleys, and planned and unplanned generating unit outages triggered the alert, said CAISO?s Fishman. Stage One emergencies are called whenever power reserves dip below 7 percent. Many ?must-offer? units were off line while under economic waiver because of the time of the year, Fishman explained. Must-offer units are power plants that are under federal mandate to provide electricity when called upon by the grid operator. However, during times of expected lower demand, such as moderate spring temperatures, CAISO allows for waivers to the federal mandate. In addition, some 10,800 MW of capacity was unexpectedly out of service because of maintenance or breakdowns. Unexpected outages occurred in units at major plants in Southern California, such as AES Huntington Beach, El Segundo Generating Station, Duke South Bay, and Thermoelectrica de Mexicali, as well as Southern California Edison?s San Onofre Nuclear Generating Station. While compact fluorescent light bulbs, weather stripping, efficient appliances, and other conservation retrofits installed in the wake of the state energy crisis still are in place, load growth may have ?overshadowed? their effect, Fishman said. Meanwhile, as the crisis atmosphere has faded, people may not be conserving.