Over the last four decades, world energy consumption has shown a twofold increase. Meanwhile, there are renewable energies gained from natural resources such as sunlight, wind, rain, tides, and geothermal heat. Broad future perspectives on renewable energies are being developed at national and international levels, while many regions and cities worldwide are formulating plans for the future of renewable energies. Along the same lines, Iran, as one of the largest fields of gas and old resources in the world, intends to produce 20000 MW of its electricity by relying on renewable energies by 2025. This piece of evidence, for instance, demonstrates that energy represents one of the crucial factors in the development of every country, clarifying that energy resources are seriously taken into account in the economic and political perspective of every country. As a result, selecting the most optimal practical opinion can effectively guide each county’s investment in energy. In this study, the technique of Fuzzy Group VIKOR (FG-VIKOR) is used to prioritize the application of different types of renewable energies in Iran, by consideration of multiple criteria such as investment requirements, existing potentials, technological advancement rate, and so on. Finally, five alternatives will be identified and ranked by eight criteria, which are themselves regulated by four decision-makers.