Bloomberg has put two nice interactive graphics online. The first one shows solar’s learning curve. For conventional panels, the price has in the past dropped 24 percent for every doubling of total installed capacity. For thin-film panels the cost has fallen 13 percent for every doubling of installed capacity.
The second one shows in which countries solar PV has achieved “grid parity”, that is, puting PV cell’s on your roof is now cheaper than buying electricity from the grid in these countries. Viewers can adjust the year and the annual rate of return.
Very nice visualisation.