Here is a graph of U.S. PV solar installations per quarter since 2010. It shows rapid growth:
http://www.renewableenergyworld.com/rea/news/article/2013/12/more-records-for-quarterly-us-solar-installations It shows "930 MW in the July-September" quarter. That means 930 MW peak output from the solar cells, not 930 MW of 24-hour baseline capacity. 930 MW baseline would be the output from an average U.S. nuclear plant. I do not know the capacity factor for solar. For wind it is roughly 30% of nameplate capacity. The peak of PV solar output matches peak demand in many places, unlike wind which tends to peak at night. Here is a recent graph of wind turbine output versus total power consumption in Denmark: http://www.renewableenergyworld.com/rea/blog/post/2013/12/postcard-from-the-future-122-wind-power-in-denmark You can see that wind is quite intermittent even on the scale of the entire landmass of Denmark. The good news is, with today's weather forecasting you can predict approximately how much power turbines over a large area will produce for the next few days, so you can schedule other dispatchable energy sources. - Jed
