The story of an early twentieth century experiment of harnessing solar power for the irrigation of cotton plantations in the tropics offers an opportunity to examine the place of energy in the economic history of Egypt before the First World War, in the context of a global energy transition during the early decades of the twentieth century. The experiment, led by the American inventor Frank Shuman, was hailed by the press as a technical breakthrough and a practical solution to ‘the coal question’. Yet despite its success, the anticipated global shift towards solar energy did not take place, and instead gave way to the advent and primacy of oil after the war. I recount this episode of technical and entrepreneurial triumph and its abrupt termination, taking place over the span of eight years, to investigate how this circumscribed event was long in the making over the long nineteenth century. I read this ‘event’ as an encounter between multiple paths of economic, technological, and environmental developments, whose consequences are affecting the way we currently debate the role of energy in political changes in the Middle East. I also use this case to raise more general questions about energy history and its problematics of periodization, how a history of infrastructure can inform a spatial reading of the modern state and its political power, as well as about the relation of micro-historical events to global and longue-durée histories.