The UNDP Accelerator Labs Network recognizes the importance of leveraging community-led innovations in support of reaching the UNDP’s moonshot goal to help 500 million people gain access to clean energy. As such, the Network maps, tests and experiments with grassroots solutions in the field of energy and in other areas of development. The SIPA Team worked with the Network to develop a comprehensive, normative framework for analyzing grassroots innovations. The Grassroots Thinking Approach provides assessment criteria of the contextual factors in which grassroots solutions emerge and exist, the characteristics of the innovation and its goodness of fit or appropriateness within the system that it exists in, and elements for “success”. Through this approach, entities can develop a better understanding of the transformative potential of grassroots solutions for improving energy access and other development indicators. The report describes this framework, presents key insights derived from research on bottom-up solutions and demonstrates application of the approach through two case studies on identified solutions in Ethiopia and Malaysia.