After the 2011 Fukushima nuclear disaster, an outcry erupted in Taiwanese society demanding a sustainable energy transition. However, the dominant sociotechnical imagination in postwar Taiwan – developmental high modernism – manifests itself in tacit answers to the questions of what a better society should be, how technical choices should be made to achieve that goal, and what the most pragmatic and viable approach is to make the particular dreamed-of future become reality. Using an approach informed by STS/SSK (sociology of scientific knowledge), this thesis explores the exclusion of alternative energy futures brought about by a high modernist imaginary and looks into its nationalist-high modernist rationality in the forms of shared story-lines, created factuality and routinised technical choices within governmental institutions. High modernism in East Asia is characterised by the authoritarian reflex of planning rationality, which gives paramount political weight to a collectivist and unitary idea of the public good which is crafted through performative technicality in constructing the impartiality and objectivity of public authority. I explore this rationality through two case studies: national planning around power shortage and reserve margins, and the setting of feed-in tariffs for renewable energy. By way of contrast, I then explore a third case study: the development of combined PV energy, agriculture and aquaculture initiatives in Linbian and Jiadong. I suggest that can this give us clues about an alternative, grassroots ‘indigenist-reformist rationality’ imaginary for Taiwan which reassembles and enacts an indigenous identity rooted in attachment to land and locality.