Ultra-Efficient Solar Panels

Under the right circumstances, solar cells from Semprius could produce power more cheaply than fossil fuels.

http://www.technologyreview.com/article/427673/ultra-efficient-solar/

And thin film solar panels get even thinner:

http://news.ncsu.edu/releases/wms-cao-thin/

This is in line with Kurzweil's predictions:

http://www.psfk.com/2011/02/kurzweil-predicts-100-solar-power-in-20-years.html