California's chance of power outages will grow in the coming days, as the state prepares to enter the most brutal stretch yet of an ongoing heat wave, officials said Sunday. Energy demand is expected to outpace supply starting Monday evening, and predictions for Tuesday show the state rivaling its all-time high for electricity demand, said Elliot Mainzer, president and chief executive officer of the California Independent System Operator. The system operator is in charge of managing and maintaining reliability on the electric grid, a challenging job during hot weather when energy demand soars as people crank up their air conditioners.