Peer effects in residential solar photovoltaics adoption—A mixed methods study of Swedish users

Neighbourhood peer effects (social influence) in the diffusion of residential solar photovoltaics (PV) have previously been identified and quantified in a number of studies. Yet, little has been known about the inner workings of peer effects in PV diffusion. In the present work, a survey and interviews were used to study peer effects among Swedish PV adopters. Participants acknowledged peer effects as important for their adoption decision, although they had in general been seriously contemplating PV adoption before the effects. The main function of peer effects appears to have been a confirmation that PV works as intended and without hassle, rather than the procreation of unexpected insights or the provision of more advanced information. Peer effects had mainly occurred through existing and rather close social relationships, rather than between neighbours that did not already know each other. Peer effects appear to have reduced barriers related to PV attributes such as low trialability and low observability of the actual results of adoption. The results suggest that passive peer effects (through seeing PV) were less important than active effects (through direct interpersonal contact), and that seeing PV rarely led to direct contact with adopters, a finding that contrast somewhat to previous literature.