How do niche actors navigate after “hype” is gone? A better understanding of the motivations and actions of technology advocates during a disillusionment phase can inform policymakers in dealing with technology and advocates facing negative expectations. Building on the conceptual notion of institutional work, we explain how biogas interest groups in Germany attempted to influence institutions when positive expectations about the technology were overwhelmed by negative ones. We shed light on their efforts to influence the Renewable Energy Act, which has provided state support for biogas generation for electricity supply, and their discursive justifications. Our analysis reveals that the interest groups predominantly drew on maintaining and creating work with the goal of protecting government support for biogas while accepting and introducing incremental changes towards enhanced economic and environmental sustainability. The narratives employed by the biogas actors addressed a broader range of stakeholders over time. Furthermore, we show that their institutional work practices were influenced by macro-level conditions, as well as by the resources and skills within the sector and actors. We identified instances of interaction between maintaining and creating work: creating work demonstrated the positive potential of technology, justified the continuation of support and helped adapt the support system to enhanced sustainability. Our work contributes to a nuanced understanding of agency in sociotechnical transitions by highlighting actors who do not engage in the typical activities of niche or incumbent actors.