The potential climatic impacts of five electrical energy technologies: coal combustion, light water nuclear reactors, the satellite power system (SPS), terrestrial photovoltaics (TPV), and fusion were assessed. Heat-Limit concerns were not considered. The objectives were to identify major issues surrounding the effect of technology deployment on climate and to assess the degree to which these five technologies might contribute to significant climatic changes. The potential impacts of the energy technologies on the climate were evaluated by comparing the emissions of heat or pollutants from each technology to the amount of such emissions currently considered necessary to produce significant climatic perturbations. Only operating emissions were considered, except for the SPS, which would involve emissions from launch vehicles. Of the technologies considered, coal technology presents the greatest risk to potential global climate changes because of its large emissions of CO2.