WASHINGTON — Energy generated in the U.S. by solar installations is still a fraction of the overall output, but for the first time ever, solar exceeded natural gas capacity additions on an annual basis in 2015.

Washington-based Solar Energy Industry Association and GTM Research say during the first quarter of 2016, the solar industry added more new capacity than coal, natural gas and nuclear energy combined. New solar installations accounted for 64 percent of all new electric generating capacity brought online in the U.S. last quarter.

The report says the solar energy industry will install 14.5 gigawatts of capacity this year, which is nearly double the number of new solar installations in 2015.

There are now more than one million operating solar photovoltaic (PV) system installations across the U.S.

“While it took us 40 years to hit one million U.S. solar installations, we’re expected to hit two million within the next two years,” said the association’s interim president Tom Kimbis. “The solar industry is growing at warp speed.”

Maryland, along with New York, have seen the strongest growth in residential solar PV installations, with growth rates of 25 percent.

Maryland is a leading solar state, with a 25 percent growth rate in residential solar installations.