To better understand the impacts and the conditions that influence sustainability of these projects, the research presented in this paper evaluated 23 local development projects post implementation. By applying an standardized evaluation design to a cross-sectional sample in terms of renewable energy sources (solar, wind, biomass, hydro), user needs (electricity, food preparation, lighting, productive uses), community management models, finance mechanisms and geographical locations, the review results provide valuable insights on the underlying conditions that influence the success or failure of these small-scale local energy interventions. The empirical evidence suggests that the sustainability of small-scale energy implementations (≤100 kW) in developing countries is determined by the same factors, independent of the socio-cultural, political and ecological context. These findings allow better predictions of the long-term success of small sustainable energy projects in developing countries, and they can help improve project designs and increase the certainty for future investment decisions.