Solar Power: Why it is the energy of the Future.

More than 100x cheaper in 35 years

For those who still doubt that solar power is about to shift into high gear and play a much bigger role, look at the graph above. It shows the price per watt, starting in 1977 at over $76/watt all the way down to $0.74/watt in 2013. While it's already very competitive with dirty sources of power in large parts of the world, a few more years of this and solar will simply be too cheap to ignore, even without a price on carbon emissions.

http://www.treehugger.com/renewable-energy/graph-shows-why-solar-power-will-take-over-world.html