I posted this in the other thread but I found this graphic to be interesting. It's from an Oilpro article and contains Exxon Mobil's assessment of future growth in various energy sources (note, this is all energy, not just electricity like the green lobby likes to focus on).
Even with 25 years of 7.7% average per annum growth in Solar (which is a huge amount), Solar will still add up to just a few percents of consumption worldwide. If that growth continues over the subsequent 25 years, that bar will start to add up to a significant amount:
http://oilpro.com/post/13695/exxonmo...0-year-smear-o