Abstract Technological innovation and widespread deployment of clean-energy technologies in emerging economies are critical for a global clean energy transition. Success or failure in this endeavour will have long-term energy and carbon consequences. A fundamental question exists about whether, and how, emerging economies can accelerate clean-energy transitions, given the unprecedented scales of their impending socio-economic and infrastructure transitions, and often-underdeveloped technological innovation capabilities and supporting finances. We reflect on this question by undertaking a retrospective analysis of past and recent large-scale rapid clean-energy technology transitions in the three largest emerging economies—of light emitting diodes in India, solar photovoltaics in China, and sugarcane ethanol fuel in Brazil—each of which grew out of an unexpected set of initial technological conditions and resulted in dramatic changes to the global technological landscape. In examining how each country overcame its conventional technological lag, we discuss synthetic lessons for accelerated clean-energy transitions in emerging economy contexts: the essential role of PSEs in leveraging economies of scale; complementarities between domestic policies and global value chains; and the continued importance of domestic R&D and academia-industry linkages. We argue that forging clean-energy pathways requires a holistic systems approach, with a shift from isolated policy approaches to a portfolio of coordinated innovation policies where demand, research and development, and manufacturing are all strategically developed.