The falling costs of renewables has helped shift political winds around power generation

Solar energy panels for a well pump in Wilcox, Arizona. Credit: Bruce Gifford Getty Images
Bob Burns didn’t always love renewables. Shortly after he was elected to the Arizona Corporation Commission in 2012, the conservative Republican voted to kill what remained of the state’s subsidy for rooftop solar installations.
But last week Burns managed something only a few blue-state climate hawks have pulled off: He helped pass a rule calling for the state to eliminate carbon emissions from its power grid by 2050.
In doing so, Arizona becomes only the seventh state to pass a law requiring its utiliti...