Long Waves in Energy History: Competing Fuel Policy Coalitions During Britain’s Long Movement out of Coal-Fired Electricity from the late 1940s to the early 1990sWorldwide coal generating capacity fell for the first time on record in 2020. Britain experienced its first prolonged period without coal-fired electricity since Victorian times, but the UK's plummeting coal consumption has roots in the mid-twentieth century. This paper assesses Britain’s movement out of coal by interrogating power station investment. It examines coal’s changing place in the national energy economy formed by the nationalisation of coal mining and electricity generation in the late 1940s before its demise following the 1984-85 miners’ strike. Coal industry and UK government archival records provide insights from across the period. Using transition theory, energy policy is understood as the outcome of a conflict between two coalitions grouped around technologies and ideological perspectives. Civil servants and Labour and Conservative ministers favoured diversifying Britain’s energy mix through imported oil and investment in nuclear power. They were suspicious of coal’s monopoly position and organised labour’s role in the industry. Diversification was a route to undermine coal’s power and secure optimal economic and political outcomes. Conversely, a coalition of unionised miners, the National Coal Board and Scottish Office officials argued for continued investment in coal on grounds of national self-sufficiency and government obligations to sustain coalfield economies. Scotland provides an important vantage on the territorial dimensions of energy policy through coalfield regions exercising influence over Scottish policymakers. Energy policy is traced across four eras between the 1940s and 1980s. Conceptions of the national interest rooted in class and sectoral alignments were linked to ideological preferences for distinct priorities in power station investment. Both coalitions experienced successes and setbacks across the four decades before the final victory of a liberalised market approach to energy in the mid-1980s ensured coal’s marginalisation.