Contractors build a lattice tower during construction of San Diego Gas & Electric Co.'s (SDG&E) Sunrise Powerlink, a 117-mile, 500-kilovolt electric transmission line that runs from Imperial county to San Diego, California, U.S., on Wednesday, April 4, 2012. SDG&E, a subsidiary of Sempra Energy, provides energy service to 3.4 million consumers through 1.4 million electric meters and more than 850,000 natural gas meters in San Diego and southern Orange counties. Photographer: Sam Hodgson/Bloomberg via Getty Images