Rooftop photovoltaic systems could produce two-fifths of the nation’s electricity, and Georgia ranks 10th among states in its potential for rooftop solar PV, according to a new National Renewable Energy Laboratory report.
“Rooftop Solar Photovoltaic Technical Potential in the United States: A Detailed Assessment” nearly doubles the federal research agency’s estimate of rooftop potential. A previous estimate placed the technical potential at 664 gigawatts of capacity; the new report ups that number to 1,118 GW.
“Analysts attribute the new findings to increases in module power density, improved estimation of building suitability, higher estimates of the total number of buildings, and improvements in PV performance simulation tools,” according to an NREL press release.
The estimate is an aspirational number: It’s based on the assumption that solar panels would be installed on every “suitable” rooftop. At the same time, it doesn’t incorporate the significant potential for non-rooftop, utility-scale installations, which currently generate more than half the nation’s solar.
In a closer look at 47 cities, the report found that Atlanta rooftops could generate 41 percent of the electricity used by residents and businesses. Columbus, Ga., faired much better in that analysis: 62 percent of that city’s power could be generated from rooftops, ranking it fifth among the 47 cities studied.