Local factors affecting the spatial diffusion of residential photovoltaic adoption in Sri Lanka

Using a zero-inflated negative binomial regression model (ZINBM), this study compares the influencing factors of PV adoption in the Colombo district of Sri Lanka, a lower-middle income country, against the well-established factors of PV adoption in developed countries. The results suggest that highly educated middle-aged persons and retirees in the Colombo district are more likely to adopt PV. In addition, early adopters reside in larger houses of average, or above average, housing quality. In the short term, policies focused on expanding the knowledge base on PV technology, as well as incentivising the initial costs of installation, could increase the adoption rate of PV systems in Sri Lanka. In the longer term, increasing opportunities for tertiary education could accelerate the diffusion of innovations, as well as narrow socioeconomic gaps by even distribution of benefits of technological innovations.