Analysis examines solar resources, PV capacity

The Energy Information Administration (EIA) maintains Southwest states have better solar resources and higher photovoltaic (PV) capacity factors than those in the Southeast or Northeast.

The EIA said on average the nation’s utility-scale solar photovoltaic (PV) power plants operated at about 25 percent of their electricity generating capacity, based on annual values from 2014 through 2017. Arizona’s utility-scale solar PV plants performed better than those in any other state, achieving a 29.1 percent capacity factor during that time frame. Arizona’s installed utility-scale solar PV capacity was 1.7 gigawatts (GW) at the end of 2017, which represents about 7 percent of the national total. Utah’s 0.9 GW of solar PV plants ranked second, with a 29.0 percent capacity factor.

California’s utility-scale solar PV plants ranked third with an average capacity factor of 28.4 percent.

The EIA said Southeast states such as Georgia and North Carolina had substantially lower PV capacity factors than southwestern states at similar latitudes while Northeast states like New Jersey and Massachusetts had even lower capacity factors.

Resource quality, tracking capabilities, and inverter-sizing considerations are considered by industry experts to be three prime factors largely determining a solar PV power plant’s capacity factor.