Arizona Public Service
Arizona Public Service Company is the largest electric utility in Arizona and the subsidiary of publicly-traded S&P 500 member Pinnacle West Capital Corporation. The utility provides power for nearly 1.2 million customers in 11 of the state's 15 counties.
Despite the fact that Arizona is the sunniest state in the U.S., it is falling far behind on solar installations, and by the end of 2015, the state had fallen from second in total U.S. installed solar to sixth.