By analysing the context of emerging and developing countries, the author explores the private sector perspective on renewable energy diffusion. The evaluation of two technology case studies, namely wind farms (grid-connected renewable energy) and solar home systems (off-grid renewable energy), reveals the perspectives of highly experienced early adopters. Thereby, qualitative and quantitative data sources - including innovative methods such as conjoint analysis - are combined. A key finding is that private sector perspectives, especially of early adopters, are highly relevant for policy makers in their endeavour of designing effective and efficient framework conditions for renewable energy technologies.