With development spreading, the U.S. residential solar power market set a record during the second quarter with new installations, an industry report said.

A report from the Solar Energy Industries Association with support from green energy market adviser GTM Research finds second quarter residential solar capacity grew 70 percent year-on-year to 473 megawatts.

The report finds that 10 states have installed more than 10 MW of solar power during the second quarter, up from the four reported during second quarter 2013.

The Lawrence Berkeley National Lab published a survey in August of about 80 percent of all U.S. residential and non-residential photovoltaic systems installed through 2014 and found national median installed prices declined 9 percent year-on-year for residential systems, 10 percent for small-scale, non-residential systems, and 21 percent for larger non-residential systems.

"U.S. solar growth has exploded and more than 150,000 American solar jobs have been created," SEIA President Rhone Resche said in a statement. "By any measurement, that's a success for both our economy and environment."

The federal government is supporting solar development through its SunShot initiative, which aims to make the renewable technology competitive. The program aims to move solar power capacity from less than 1 percent of the national electricity supply to 14 percent by 2030.

A federal investment tax credit for solar installations is scheduled to expire at the end of next year.