The U.S. added 6,681 MW of net natural gas-fired capacity in 2013, far outstripping any other generation source, according to Energy Information Administration (EIA) data. This figure represented a substantial drop from 2012, when 9,210 MW of new gas capacity was added, but it still accounted for just over 50% of total additions last year.

U.S. capacity additions in general plummeted from 2012, when 28,801 MW was added, to just over 13,500 MW in 2013. The drop was almost entirely accounted for by wind, which added 12,885 MW in 2012 but only 1,032 MW last year as the Production Tax Credit was allowed to expire.

New capacity was not equally distributed across the country, however. California alone accounted for nearly two-thirds of the total, with six large combustion turbine or combined cycle plants opening last year, along with a number of other smaller projects. Only one other state—Florida—added more than a gigawatt of new gas capacity in 2013 (the 1,200-MW Cape Canaveral facility, a POWER Top Plant).

Solar continued its strong growth in recent years, adding just under 3 GW nationwide, though again most of this—just over 2 GW—was also in California.

Concerns about fuel diversity are unlikely to ease in the near future, as the outlook for 2014 and beyond continues to be dominated by gas and renewables. EIA data records almost 7 GW of planned natural gas–fired capacity additions for 2014, out of a total of about 15 GW. Texas will dominate natural gas this year, with about 2,300 MW of new combined cycle plants coming online. Wind is poised for a comeback with a planned 4 GW, while solar should add just under 3 GW—again, with the lion’s share of that in California.

Meanwhile, coal and nuclear continue to dominate planned retirements, with about 1,700 MW of coal and 600 MW of nuclear going offline this year, according to EIA data, and a whopping 15 GW of coal shuttering in 2015 as the Mercury and Air Toxics Standards (MATS) go into effect. MATS took a big step toward implementation last week as the U.S. Court of Appeals for the D.C. Circuit turned back a raft of challenges in a consolidated appeal by coal and industry groups.

—Thomas W. Overton, JD is a POWER associate editor (@thomas_overton, @POWERmagazine)