This paper aims to understand the role of green entrepreneurs in urban sustainability transitions. We propose an analytical framework combining transition approaches and green entrepreneurship from a relational lens. It includes four processes: emergence of green entrepreneurs, multi-scalar interest coordination, empowering through anchoring, and struggling with the regime at the urban scale. This framework is illustrated through an empirical analysis of the role of green entrepreneurs in the development of the solar water heater industry in China’s Solar City. The analysis unravels how the local institutional contexts and multi-scalar relations empowered local green entrepreneurs to become system builders for urban transitions.