Policymakers and academics are increasingly discussing the need for innovation in the energy sector to support the societal transition toward net-zero. To this end, mobilizing finance for novel energy technologies is a significant challenge. Remarkably, the scientific literature about the financing mechanisms for novel energy technologies often neglects the difference between invention, radical innovation, and incremental innovation. Recognizing the difference is essential to defining ad hoc financing mechanisms, increasing the likelihood of developing and implementing such technologies, which can contribute to Sustainable Development Goal (SDG) 7, SDG 9, and SDG 13. This paper highlights the need for a critical rethinking of the approach and the vocabulary related to the financing mechanisms for novel energy technologies. Leveraging a multiple longitudinal case study, the paper provides empirical evidence of the different financing mechanisms for the transition from invention to innovation in the energy sector. By bringing together the findings and existing literature, this paper provides a novel analytical framework to link financing mechanisms and the different phases of the innovation process in the energy sector. The framework is also a starting point for future research on the different phases of the innovation process and related financing mechanisms.