How to get photovoltaics on the roofs? Empirical evidence on homeowner support for a residential solar mandate in Germany

This study evaluates whether a residential solar mandate in the case of roof renovation is a useful instrument for further photovoltaic (PV) adoption. Based on a survey of German utility customers (N = 1,334), the study discusses (a) how determinants that influence PV ownership and PV installation intentions of single-family homeowners might interact with a residential solar mandate, and (b) factors that influence homeowner support for a solar mandate and the perceived effectiveness of such a mandate in mitigating climate change. Our empirical results show that a residential solar mandate is a rather unpopular policy measure among homeowners. However, we identify two factors that increase the intention to install photovoltaics which can be strengthened by a residential solar mandate: the perceived social desirability of PV expansion in one’s own environment and a necessary roof renovation as a window of opportunity. We recommend that the introduction of a solar mandate should be accompanied by an active information policy on the environmental benefits and the cost implications of PV expansion.