Knowledge path dependence in energy innovation: the role of spillovers and green absorptive capacity in renewable and non-renewable technology diffusion

Abstract The innovation and diffusion of renewable energy technologies are critical to advancing the energy transition. This study investigates how knowledge acquisition through spillovers from renewable and non-renewable patented technologies affects the subsequent diffusion of these technologies. Using a dataset comprising 12,966 renewable energy patent families and 24,067 non-renewable (fossil fuel-based) patents owned by firms between 1990 and 2010, we analyse backward citations as indicators of knowledge spillovers and forward citations to trace knowledge diffusion. We classify spillovers into three types: clean spillovers, dirty spillovers, and external spillovers (originating from non-energy fields). Our results show that, for renewable technologies, clean spillovers have a positive and significant effect on diffusion, while dirty spillovers hinder it, indicating a clean knowledge path dependence. In contrast, for non-renewable technologies, dirty spillovers significantly promote diffusion toward other non-renewable technologies, confirming a dirty knowledge path dependence. Green absorptive capacity does not moderate spillovers in the case of renewables, but it does reduce the influence of non-renewable spillovers on the diffusion of dirty technologies. These findings have important implications for innovation policy and knowledge transfer mechanisms aimed at accelerating the energy transition.