According to SolarBuzz, http://www.solarbuzz.com, The U.S. installed 4.2 gigawatts (GW) of solar power during 2013, a fifteen percent growth over 2012.
Utility and industrial scale projects accounted for more than 80 percent of new solar capacity. Good project finance rates and demand for projects from utilities to meet state renewable requirements has driven growth, accounting for over three-fourths of these large scale projects. The remaining 20 percent was installed mainly on residential rooftops.
California was again the leading state in the U.S. for installed solar PV in 2013; North Carolina and Texas expanded the fastest. Maryland and Colorado dropped from the list of top states. These changes mainly result from changing state policies and incentives for solar, with some states improving incentives and some states eliminating past programs.