Nearly 40%, or 10.4 GW, of utility-scale solar photovoltaic (PV) systems operating in the US at the end of 2017 were fixed-tilt PV systems rather than tracking systems. Of the utility-scale fixed-tilt solar PV systems, 76% of the capacity was installed at a fixed angle between 20 degrees and 30 degrees from the horizon, the US Energy Information Administration (EIA) says in a new article.