San Diego has an ambitious plan to store renewable energy, using extra solar power to pump water up a mountain. This old-style "water battery" technology could be set for a revival.
California's grid manager warns of rolling blackouts on Tuesday evening. Electricity demand expected to reach an all-time record of more than 50,000 megawatts
California's grid holds up another night as a prolonged, broiling heat wave continues. Demand surges to more than 50,000 megawatts, setting a new record