Electricity demand is so high in California — the state is operating at 95 percent capacity — that state and utility officials are asking residents to save energy by turning on their Christmas lights a few hours later at night. Southern California Edison, for example, asked its customers to wait to turn on their sure-to-be-heartwarming light displays until after 8 p.m. The California Independent System Operator, which runs the electricity system for three-quarters of the state, said that Christmas lights add about 1,000 megawatts of consumption statewide, while Edison disagreed and said the total for its territory alone in California would be about 1,400 megawatts. For comparison, 1,000 megawatts of power is enough to supply about 1 million homes.