In 2015, wind provided 47% of new generation capacity. Gas came in at 35%, followed by solar at 14%, while coal, oil and geothermal accounted for less than 1%. Total new generation capacity was 14,468 MW. For more information, see https://www.snl.com/InteractiveX/Article.aspx?cdid=A-34950800-13103.
All this is happening despite loud skepticism about climate change and clean energy. This is pure economics, the cost of wind and solar generations have dropped below the cost of new coal generation.
See the details in these charts from SNL Energy.