When subtracting retirements of coal and natural gas from additions of these fossil fuel sources, we get all the way back to 2009 before capacity additions starts to outpace capacity retirements. In a simple way, all of the utility-scale electricity generation capacity added to the United States grid since 2009 has been clean energy.
The electricity generation industry – mostly in retiring so much coal and replacing it with natural gas – has managed to lower overall emissions by 12% since 2005. During this time, US electricity demand has stayed mostly flat. It was only very recently, 2015 or so, that the volumes of wind and solar power installed became considerable enough to dent the amounts of fossil fuels being burnt – meaning not only has a flat amount of fossil fuels been installed, its also been running less.