Houston?! Why Houston? That was the question last week, when NRG Energy announced its plans to make our city home to the nation's largest network of charging stations for electric cars. To put it kindly, our sprawling megalopolis doesn't strike the rest of the world as a leader in greening the planet. "Are you taunting the oil industry?" a Dallas Morning News reporter asked David Crane, NRG's chief executive, during the conference call in which he announced the plan. Crane laughed. "Let me state for the record," he replied, "we're not taunting the oil industry." Instead, it turns out that...