According to a just released study by the Solar Energy Industries Association and GTM Research, the demand for solar power installations in the US is booming, fueled in part by a global oversupply of solar technology. GTM Research forecasts that 3.2 GW of solar generation will be installed in 2012, up from 1.9 GW in 2011. (For comparison, total installed electricity generating capacity in Ontario, Canada, is about 36GW, according to the Ontario Independent Electricity System operator.)
In Q3 of 2012:
- The residential market grew 12% over Q2 2012 and had its largest quarter in history.
- The non-residential market grew 24% over Q2 2012.
- There is now a total of 5.9 GW of PV operating in the U.S. from over 271,000 installations.
The top three states by total installed solar capacity are California, New Jersey, and Arizona.
An Executive Summary, slide show and fact sheet from the report are available at http://www.seia.org/research-resources/us-solar-market-insight Lots of information in each of the three documents. The full report can also be purchased, with industrial pricing ($5,995), from this location.
gallondaily 
Well said, but everyone needs to understand that adding Solar in their house is an asset that should boost the long term value of their residence if / when they decide to sell. With the environment the way it is going we are unable to overlook any product that delivers 100 % free electricity at no cost to both the shopper and more significantly the environment!