In this article, we explore the process of economic change following the NGO-led implementation of a small-scale off-grid hydropower system in Tanzania. We examine how the implementing actor deals with economic challenges and local ownership in order to achieve sustainable electricity supply. The qualitative case study shows that the NGO, ACRA-CCS, has overcome a number of constraints, which are sometimes associated with donor funding. This has been achieved by having multiple donors, an integrated approach and a longer presence. The ‘logic’ of implementation included active enhancement of productive electricity use, community services and benefits. As a result of these actions, the customer base grew quickly, rather than it taking many years to develop. The case illustrates the process whereby an off-grid system becomes economically viable. Local ownership has led to the project becoming an arena for community collaboration and problem solving, and creating values such as effective load management and protection of infrastructure. We suggest that attention should be given to possible public private community partnerships (PPCPs) – involving communities as crucial partners. The choice of a socio-technical system perspective was fruitful and provided crucial insights into how different factors manifested, interacted and played out in practice.