After the 1973 oil crisis, scientists and researchers in and beyond America increasingly joined a heated debate on determining the more favorable energy alternatives to fossil fuels, with pro-nuclear scientists arguing for the advanced development of nuclear-fission powered breeder reactors in order to maximize power supply, and the antinuclear researchers arguing for the implementation of small-scale, roof-top style solar energy technologies which according to them would fuel a more economically sustainable and environmentally benign development. The stake of the debate was whether or not to embrace a more social-democratic reconfiguration of energy technologies in a big-industry dominated economy that favored the centralized mode of energy production, as represented by the production of nuclear power. This paper revisits the 1970s’ energy debate from the aspect of scientific reasoning. It focuses specifically on three texts by the antinuclear researcher Amory Lovins, the solar energy supporters of the Union of Concerned Scientists, and the pro-nuclear International Institute of Applied System Analysis; seeing the three texts as efforts to promote competing expectations for energy futures, I argue that the solar energy supporters were able to lay out scientifically legitimate energy strategies that challenged the case of their pro-nuclear peers with the help of models. Modeling was a vital tool for the antinuclear and pro-solar researchers to reframe the complexity of the energy problem, incorporate the uncertainties, and support their interpretation of energy efficiency not as maximizing supply through technological breakthroughs but as raising the cost-effectiveness of utilizing easier accessible energy supplies. Modeling, which blurs the boundary between scientific and political claims, helped the antinuclear researchers to advance their arguments within American society’s interest divisions and value conflicts.