Although a small body of research has examined the motivational foundations of homeowners' decisions to adopt rooftop solar panels, in this research we compared adoptive and non-adoptive homeowners in the United States (N = 824) across a spectrum of values and motives to identify the most salient predictors of solar adoption within various demographic and political strata. Results of hierarchical logistic regressions revealed that autonomous (i.e., internal) pro-environmental motivation linked to solar adoption regardless of age, income, and education. In contrast, the effects of altruism and controlled (i.e., image and status based) environmental motivation depended on demographic characteristics. That is, altruism was positively associated with adoption for older homeowners, but negatively linked to adoption for younger homeowners. Additionally, controlled motivation predicted solar adoption for both younger and higher income homeowners, but it was not a predictor for older and lower income homeowners. We highlight the importance of assessing interactions between demographics, on one hand, and motives and values, on the other, in order to reveal nuances in the motivations of different types of adopters. These findings underscore the need for more targeted solar policy, marketing, and public messaging.
