I perform a comprehensive econometric analysis of the demographic determinants of residential solar installations in the contiguous United States. The exponential growth of residential solar in the United States has been aided by declining component costs, environmental concern, and government incentives. Contentious debate surrounds solar incentives as there is uncertainty over their efficacy and equity. Previous research has attempted to provide context to this debate by modeling the development of residential solar in the United States, but it has relied upon partial datasets and Generalized Linear Models. I utilize the comprehensive DeepSolar database on residential solar in the US and, contrary to previous research, find that a Cragg Hurdle model specification outperforms the Generalized Linear Model frameworks. Results of this model suggest that solar incentives have had a positive impact on residential solar development and that residential solar adoption in the United States has been pursued by counties that are characterized by the middle class. This suggests that solar incentives have been both more effective and perhaps more equitable than previously thought.