For the first three quarters of 2015, renewables accounted for 60.2% of the new U.S. electricity generation capacity, according to the Federal Energy Regulation Commission (FERC).
The cumulative installed capacity of 7,276 MW consisted of biomass, geothermal, hydropower, solar, and wind. This ran from January 1st through September 30th. It included 2,966 MW of new wind capacity, 40.76% of the total, as well as 1,137 MW of solar, 205 MW of biomass, 45 MW of geothermal steam, and 27 MW of hydropower. Within the same period, natural gas generation capacity grew by 2,884 MW.
During the month of September, the new generation capacity list was topped by wind with 448 MW. Following wind, natural gas was second with 346 MW, and solar was third with 20 MW of new capacity. Because FERC does not fully account for distributed generation in its reports, the critics recognized that the renewable numbers, especially those for solar, were underestimated.
There was no new nuclear capacity added in 2015, and only 9 MW of oil and 3 MW of coal were added. In the July of 2015 report, the renewables share of net generation totaled at 13.6%. Research by renewables advocates suggested FERC and EIA do not fully account for distributed energy resources in their measurements. This means that actual renewable energy penetration is higher than the figures suggest. Throughout the nation, rooftop solar is estimated to be at about 45% of installed solar capacity.
Experts in the field of the wind and solar industry are most concerned about sustained growth. Wind advocates are lobbying Congress to extend wind’s now-expired $0.023/kWh federal production tax credit. At the same time, solar advocates are lobbying to keep congress from letting its 30% federal investment tax credit revert to 10% for commercial solar, and zero for residential solar on December 31, 2016.
Read more here.