Federal number crunchers said the shutdown of the seaside San Onofre Nuclear Generating Station is partially to blame for a 59 percent increase in wholesale electricity prices for California during the first half of the year.
The Energy Information Administration said the closure also caused a "large and unusual separation" in power prices between the northern and southern parts of the state. Southern California prices were much higher.
Agency spokesman M. Tyson Brown said the main reason for the increase is the rebound in historically low natural gas prices. Natural gas generation is California's principal source of electricity.
U-T San Diego reports a wholesale price spike could mean higher average utility bills. Utilities must get regulatory approval before passing the costs onto consumers.
The nuclear plant provided energy to supply 1.4 million homes.