There are now over 13,000 MW of cumulative solar electric capacity operating in the U.S., enough to power more than 2.2 million average American homes. There were 140,000 new solar installations in the U.S. during 2013, bringing the total to over 445,000 PV systems operating today. The utility market led the charge again with 2,847 MW of PV and 410 MW of Concentrating Solar Power (CSP) installed in 2013.
Data source.