We focus on how the concept of knowledge infrastructure can help interrogate both the novelties and continuities in energy transitions. In particular, we turn attention to research, innovation, and knowledge production capacities in renewable energy transitions. We outline the subfield of knowledge infrastructures and introduce concepts relevant to energy research. We especially illustrate the ways that knowledge infrastructures may support or adapt to change, and also the ways that they display ‘legacy’ properties that inhibit, slow or outright prevent transitions. To ground our investigation, we briefly examine research in Scotland’s marine energy sector as the nation pursues a transition from an energy sector heavily reliant on oil and gas, to one based on renewable energy innovation and implementation. Via this case, we illustrate that a great deal of the ‘old’ knowledge infrastructures for energy research, rather than being wholly swept away, instead persist across energy transitions. The concept of knowledge infrastructures provides a powerful addition to energy social science because they are fundamental to our ability to research and develop renewable energy technologies, and so play an important role in defining possible energy futures.