From unbroken optimism about progress to targeted PR work: How hydropower companies began to manage public emotions. Today, the expansion of renewable energies is being fought over more than ever. But already in the mid-20th century, massive investments in the construction of hydroelectric power plants caused conflicts: the vision of inexhaustible, clean electricity was contrasted by concerns about the destruction of nature and landscape and criticism of the lack of participation of the affected population. Historian Fabian Zimmer examines these public disputes of the 1950s based on industrial films and other PR materials of three exemplary hydropower companies: Bayerische Wasserkraftwerke AG in Germany, Vattenfall in Sweden and Electricité de France in France. The author analyses how the companies used films to manage the public's emotions towards hydropower development. He elaborates the narratives and justification strategies of corporate PR, ties them into the broader debate contexts and is thus able to show how the handling of emotions in public disputes about energy infrastructures changed in the 1950s.