Local factors driving the diffusion of solar photovoltaics in Sweden: A case study of five municipalities in an early market

Local factors influencing the rate of diffusion of residential photovoltaic (PV) systems are insufficiently understood. This multiple-case study explored five Swedish municipalities which have had a particularly high PV density in terms of number of installations per capita, compared to other municipalities. The aim was to identify and assess local factors that could explain these relatively high rates of PV diffusion. This was done through a survey sent to PV adopters in the five case municipalities, interviews with local actors and comprehensive Internet search queries. These five cases were also compared to fifty municipalities with low PV diffusion rates, which were studied in less depth. Peer effects (individuals influencing each other to adopt PV) and local organisations promoting PV were identified as important explanatory factors for the high local PV diffusion rates. In particular, electric utilities have successfully taken an active role in supporting PV, purchasing the surplus electricity of PV adopters, selling turnkey PV systems and disseminating information through seminars and their web pages