This study proposes a methodology for evaluating energy technologies according to their environmental impact, both for the present and future. The methodology emphasizes the use of quantitative data relating to six key parameters: the quality, quantity and renewability of the available energy used and the maintainability, efficiency and sustainability of the end-use technologies. These parameters are incorporated into an original objective function that obtains a value for each of the energy-technology-environment interactions. This methodology was applied to three separate scenarios relating to Mexico＇s future energy use in order to evaluate the environmental impact of ten end-use technologies. This approach is applicable to any nation or region interested in making informed choices about its energy future.