Ray Kopp enjoyed tooling around in a hydrogen- powered Honda prototype vehicle so much that, for a moment, he pictured driving one home. Then Mr. Kopp, an economist at Resources for the Future, remembered the car's price tag - $1.5 million - and his hopes were dashed. Therein lies the core of America's energy problem. Short of radically altering America's driving habits, the United States cannot achieve energy independence without spending billions of dollars on new initiatives. And no political consensus exists to spend those sums despite decades of promises to cut oil imports. But new plans are emerging that...