California undertook its first rolling blackouts since the 2001 energy crisis, as a heatwave slammed the Western U.S. Friday and Saturday. Electricity demand for air-conditioning throughout the region stretched California's power capacity and limited the state's ability to import power from nearby states. But the blackouts were also a side effect of the state’s increasing shift to solar power and away from natural gas-fired generators, according to state grid operator CAISO and Wood Mackenzie analysts.