Here is a back-of-the envelope analysis of how much money the US could save by converting completely all vehicles from petroleum to wind and solar.

"One way to imagine this is that we taxpayers pay for the systems each year through taxes. Meanwhile, we pay less for our electricity and gasoline, without the charge for burning fuel. By 2024, our outlay is smaller than our savings, and we then start making money and have energy self-sufficiency, guaranteed steady energy prices, no energy blackmail from the Middle East, and have avoided the greater part of the CO2 we would otherwise produce."

Somewhat pie in th sky, but a better investment than the war in Iraq IMHO.