Off-grid solar systems are often the least expensive option for rural electrification. Solar home systems can power individual households, while mini-grids can supply entire villages. Each comes with its own advantages, disadvantages, and challenges. The aim of this session is to explore challenges as well as success stories. It takes well-functioning components such as battery systems, charge management and inverters to make projects successful. Proper system sizing, maintenance and repair management, as well as a robust financial concept are also necessary. If one of these elements is missing, the electrification will not be sustainable. This session will focus on the aspects mentioned above. The speakers will present successful and unsuccessful approaches and discuss what can be learned from them.