"Using the sun cannot be plan A, because as far as I've heard, solar panels barely output enough energy to pay back the energy it takes to make them."<p>This was true 20 years ago, but now it's closer to 1% than 100% (and as that happens the cost per watt has gone down from $50 to $1 and below), though I don't have the direct reference on hand. But I think it's cited in this presentation (<a href="http://khoslaventures.com/presentations/Google-4-22-09.ppt" rel="nofollow">http://khoslaventures.com/presentations/Google-4-22-09.ppt</a>) or this video (<a href="http://www.youtube.com/watch?v=euXfy9c3Vuw&#38;feature=channel_page" rel="nofollow">http://www.youtube.com/watch?v=euXfy9c3Vuw&#38;feature=chann...</a>)