Why Solar Energy usage is exploding!

At some magical threshold, the price of solar per watt (in orange) hit some tipping point and installation exploded (the blue part), dwarfing anything from the past. And the beauty of having exponential growth on your side is that very quickly, even the current blue spike will look tiny.

http://www.treehugger.com/renewable-energy/striking-chart-showing-solar-power-will-take-over-world.html