- A new study from the National Renewable Energy Laboratory (NREL) puts the potential technical installed solar capacity of United States rooftops at 1,118 GW, with an annual generation potential of 1,432 TWh.
- That amount of potential installed capacity generation is roughly equal to 39% of 2013 U.S. electricity sales and doubles NREL's 2008 estimates of generation potential.
- The difference in higher estimates is due to increases in solar PV module density, higher estimates of total number of buildings and improvement in simulation tools for PV performance, the study said.
Considered a more "detailed and extensive" technical study than done in the past, PV Magazine notes the study significantly boosts the potential for US rooftops on buildings and homes to generate electricity from distributed solar systems.
The researchers used detailed light detection and ranging (LiDAR) data, geographic information system (GIS) methods, and modeled potential PV generation to calculate the suitability of rooftops for hosting distributed solar systems in 128 cities and representing about 23% of U.S. buildings.
"An accurate estimate of PV's technical potential is a critical input in the development of regional deployment plans," said Pieter Gagnon, an engineering analyst of solar policy and technoeconomics at NREL and lead author of the report in a statement. "Armed with this new data, municipalities, utilities, solar energy researchers, and other stakeholders will have a much-improved starting point for PV research and policymaking, both regionally and nationwide."
The report noted only 26% of the total rooftop area on small buildings within the 128 cities studied was desirable for distributed solar systems, but the "sheer number of this class in building" means these structures hold the greatest "technical potential" for rooftop solar.