Renewable energy has become a potent rallying cry uniting Hollywood and the Beltway. “We can move our economy town by town, state by state to renewable energy and a sustainable future,” Leonardo DiCaprio says in his eight-minute climate movie Carbon, released in August. In his fiscal-showdown speech during his first term, in April 2011, President Obama put Paul Ryan’s proposals for a 70 percent cut in clean energy at the top of his list of reprehensible and unnecessary reductions. “These aren’t the kind of cuts you make when you’re trying to get rid of some waste or find extra savings...