We utilize a dataset that measures existing rooftop solar installations and classifies rooftops in terms of insolation, azimuth angle and pitch, shading, and size, from aerial imagery last updated in 2017. Analysis of these data reveals that rooftop solar adoption, defined as the number of buildings with existing photovoltaic (PV) installations divided by the total number of eligible buildings, was on average low (mean of 0.93% for 10,417 U.S. ZIP codes). Regarding potential electricity generation, fifteen states could meet their residential electricity demand if panels were placed on all suitable buildings. We conduct a linear regression analysis to elucidate factors that positively (insolation, retail electricity price, Democratic voting fraction, net metering, fraction of science or engineering degree holders) and negatively (fraction of business or education degree holders) correlate with solar adoption. The results suggest anticipated electricity cost savings as a strong motivator for PV adoption, particularly in majority Republican areas, underscoring the importance of programs such as net metering that directly compensate homeowners for generated electricity. Knowledge and installation cost, however, remain barriers. Knowledge campaigns regarding technical aspects of installation and maintenance, as well as increased and stable financial incentives, may stimulate further PV deployment.
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