Energy services social enterprises are emerging as a sustainable response to the challenges of achieving SDG 7, but detailed case study insight is lacking to inform the sector. Malawi has one of the lowest electricity access rates in the world, with a rural electrification rate of only 4%. This paper highlights lessons from an energy service social enterprise in Malawi, using a case study framework to outline key achievements and challenges faced. The learning is used to form recommendations on increasing the impact, growth and sustainability of energy service social enterprises, both for grassroots practitioners as well as policy and investment decision makers. It has been found that energy service social enterprises need to develop robust strategies for sustainability through fostering cross sectorial linkages, investing in capacity building and awareness raising, collaborating through research partnerships, budgeting and resource planning conservatively, tracking social impact to inform business strategy, seeking innovation in business planning, and utilising smart subsidies. The case study analysis presented is intended to inform other social enterprises offering energy services, and to progress the rural electrification sector to achieve Sustainable Development Goal 7.