<p>Considering the diminishing nature of fossil fuels, their associated air pollution, and major contribution to global warming, renewable energy resources have attracted the attention of researchers and government policymakers around the world. This is mainly because they are clean, locally available, environmentally friendly, and ensure our future energy demands. Despite their current expensive cost, they will eventually become economically viable. Nonetheless, the type of renewable energy resources and feasible extractable amounts of renewable energy from such resources are region specific. This study investigates five climatic zones of a vast country like Iran and provides suitability of various renewable energy resources (i.e., solar, wind, geothermal, hydro, and biomass) for each region. Ranking of their suitability is determined using five main criteria of technical, pecuniary, environmental, social, and reliability. Opinions from experts have also been used to identify sub-criteria that are relevant to each of the main criteria. The criteria were weighed using the fuzzy best–worst method and evaluation and ranking of different energy production resources for each region, were carried out using the FTOPSIS, FVIKOR, and FCOPRAS methods, all of which belong to multi-criteria decision-making field. The results of this research and investigation rank solar energy as the first option for the four climatic regions of Iran, where sunlight is available throughout the year, and wind energy as the first option only for its “temperate and humid summer, temperate winter” region. The weighing criteria of the obtained results were validated via ChatGPT of OpenAI.</p> Graphical abstract <p></p>