The largest solar plant in the world just went live in the Mojave Desert. “The plant consists of three 459-foot tall towers each with tens of thousands of robotic, garage-door sized mirrors that angle sunlight toward a water boiler sitting atop them”

+ A key question: Is Keystone worth the fight? Either way, it serves as a case study for how an issue can rise above the din and become a nonstop topic of political debate.