US solar generating capacity looks likely to increase by more than 50% in 2016.

The United States added more than 4,134 megawatts of new PV installations in the third quarter 2016, a record. Total solar capacity stood at 35,800 megawatts at the end of the quarter. Residential rooftop systems account for 21% of total solar capacity.

One third of all residential rooftop systems are in a single utility service territory: the Pacific Gas & Electric Company in northern California.

The top 10 states for new solar installations in the third quarter were California, Utah, Texas, Georgia, Colorado, North Carolina, New Mexico, Arizona, Oregon and New York.

California is the first state to have reached 1,000 megawatts of new installations in a single quarter.

Average system costs, measured using a bottom-up approach of adding up wholesale prices of system components, dropped 5.1% to 6.8% in the third quarter alone. Residential system costs fell 5.1%. Commercial and industrial system costs fell 5.6%. Fixed-tilt utility-scale costs fell 6.8%.

The average cost for a residential rooftop system was $2.98 a watt during the third quarter. It was $1.69 a watt for flat roof C&I solar. Utility-scale costs were $1.09 on average for fixed-tilt systems and $1.21 for single-axis tracking systems.

The data is in a “US Solar Market Insight” report issued by GTM Research and the Solar Energy Industries Association in early December.