Thanks for all the great comments! A few things I'd like to note:
I agree that solar alone is not enough, but I also think we can get to 100% renewables -- what will get us there is political will. Look what's been done in Wildpoldsried, Germany, a town that now has an energy surplus: http://green.blorge.com/2011/08/wildpoldsried-germany-now-has-an-energy-surplus-generating-5-7-million-in-revenue/. And Gainseville, Florida, isn't doing badly either: http://www.renewableenergyworld.com/rea/blog/post/2012/01/gainesville-florida-becomes-a-world-leader-in-solar and http://biomassmagazine.com/articles/5856/grand-opening-held-for-100-mw-biomass-facility-in-florida
There's even evidence that we could be closer than we think to 100% renewables: http://cleantechnica.com/2013/02/16/100-renewables-could-be-closer-than-we-think/ and http://www.sciencedirect.com/science/article/pii/S0378775312014759
And guess what, most Germans are not so upset about the costs of renewables -- a recent poll shows that most favor renewable energy and many even think its progress in Germany is too slow: http://cleantechnica.com/2013/02/10/germany-solar-subsidies-poll/
Yes, renewable energy has been made a partisan issue in the U.S., but it shouldn't be -- if we wreck our planet, it will affect people of all parties. And renewables are proving more and more economical. I hope we can all work together to do what's best for all of us.