Solar Power

I found an interesting table in a 2002 NREL report on solar power technologies (so it is in 2002 dollars), showing the price per kWh for various technologies:

So even in 2002, Parabolic Troughs and Power Towers were looking pretty promising! These technologies, when employing thermal storage, have now been developed (as of 2011) to a maturity level where they can achieve price-parity with conventional (fossil) fuels, at least in the Southwest United States.