摘要： Off-grid solar photovoltaics have come to play a leading role in the current challenge of achieving the 7th Sustainable Development Goal of access to modern energy for all by 2030. In this context, the goal of achieving scale and accelerating growth in the off-grid solar market is now considered prominent and urgent. This paper presents an ethnographic account of the diffusion of Solar Home Systems (SHSs) under the Renewable Energy for Rural Economic Development (RERED) project in Sri Lanka which came to an end in 2011. Based on ethnographic data from 2012 and 2018 it shows that a successful model for the diffusion of SHSs is not necessarily or automatically the same as a successful model for lasting energy access. The paper thus challenges the assumption that accelerated growth in the off-grid solar market will lead straightforwardly to sustainable access to electricity for people in countries of the global south. Focusing on the experiences of project administrators, solar installers and owners of SHSs during and after the RERED project it provides insight into how diffusion was achieved on the ground and with what consequences after the project came to an end. It argues for a need to look at the different kinds of relations, imaginaries, ideas and practices involved in diffusion in action in order to better understand what is being achieved on the ground.