Land Requirements for Utility-Scale PV: An Empirical Update on Power and Energy Density

The rapid deployment of large numbers of utility-scale photovoltaic (PV) plants in the United States, combined with heightened expectations of future deployment, has raised concerns about land requirements and associated land-use impacts. Yet our understanding of the land requirements of utility-scale PV plants is outdated and depends in large part on a study published nearly a decade ago, while the utility-scale sector was still young. We provide updated estimates of utility-scale PVs power and energy densities based on empirical analysis of more than 90% of all utility-scale PV plants built in the United States through 2019. We use ArcGIS to draw polygons around satellite imagery of each plant within our sample and to calculate the area occupied by each polygon. When combined with plant metadata, these polygon areas allow us to calculate power (MW/acre) and energy (MWh/acre) density for each plant in the sample, and to analyze density trends over time, by fixed-tilt versus tracking plants, and by plant latitude and site irradiance. We find that the median power density increased by 52% for fixed-tilt plants and 43% for tracking plants from 2011 to 2019, while the median energy density increased by 33% for fixed-tilt and 25% for tracking plants over the same period. Those relying on the earlier benchmarks published nearly a decade ago are, thus, significantly overstating the land requirements of utility-scale PV.