Twenty years after the World Commission on Dams published an oft-cited critique of hydroelectric projects across the globe, the energy infrastructure has experienced a renaissance. Dams, however, remain a highly contested energy source. In this article, we use two iterations of political ecology to challenge and complicate contemporary framings of hydropower as 'sustainable.' Focusing on political ecology's grounded, empirical reading of broader environmental and epistemological claims, we identify two different ways that insights from political ecology can reveal the contemporary relevance of the local scale in critiquing global hydropower infrastructure and its claims to be a part of global decarbonization agendas. Drawing from recent fieldwork in Bolivia and Brazil, we adopt frames of 'plurality' and the 'production of space' to analyze how local-scale dynamics of dam building challenge dominant definitions of sustainable hydropower. With the 'green-ness' of contemporary hydropower based on a narrow, CO2-centric definition, these insights complicate, challenge and broaden this definition by illuminating how the impacts of this energy infrastructure and power networks contradict claims of 'sustainability' and widen the relevance of respective projects' impacts, in terms of socionatures and ontologies. We argue that these hydropower projects limit the generative capacity of the local scale, in terms of place-based politics and socio-natures, and remake land-and waterscapes in the image of state and transnational extractive regimes. Together, our analysis opens up new trajectories for political ecology, to question the socio-environmental politics generated and enabled by the reworked environments of green energy production.