December is most popular month for wind, solar installations

December is the most popular time of year for the addition of new onshore wind and solar photovoltaic (PV) electricity generation installations, according to the U.S. Energy Information Administration (EIA).

From 2010 through 2018, 43 percent of all onshore wind capacity and 33 percent of all solar PV capacity have been added in December. The fact that U.S. wind and solar capacities receive a production tax credit (PTC) and an investment tax credit (ITC), respectively, may explain why there’s so much activity at the end of the year. In 2018, 58 percent of wind capacity additions were installed in December, the highest share since 2013. Further, 31 percent of solar PV capacity additions were in installed in December 2018, which is about average.

The EIA also reported that 45 percent of all-natural, gas-fired capacity additions between 2010 and 2018 occurred in the second quarter of the year. Last year, U.S. natural gas-fired generating capacity additions accounted for almost 50 percent of the annual additions. Installations in the second quarter help ensure that adequate capacity is available to meet peak summer electricity demands.

Capacity additions from sources besides wind, solar PV, and natural gas are more evenly distributed throughout the year, EIA reported.