This study presents a comprehensive framework for Solar Energy Potential Mapping (SEPM) and optimal site selection for photovoltaic (PV) power plants in the mining regions of South Khorasan Province, Iran. A hybrid approach was developed by integrating Geographic Information System (GIS) analysis with Fuzzy Analytic Hierarchy Process (FAHP) and fuzzy overlay techniques. The assessment incorporates multiple spatial criteria, including climatic, topographic, environmental, and infrastructural factors. The results indicate that climatic variables, particularly PVOUT, are the primary drivers of solar suitability. Comparative analysis shows that while the fuzzy overlay model identifies broad potential zones, the FAHP model provides a more constrained suitability pattern. By synthesizing these methods through a Coupled-SEPM (C-SEPM) approach using the fuzzy GAMMA operator, a balanced and high-precision suitability map was produced. Validation against existing PV facilities confirms the high predictive accuracy of the C-SEPM framework. Numerical results from the final C-SEPM model reveal that 23.5% of the study area falls within the “very high” suitability class, while 33.3%, 30.5%, and 12.7% are classified as “high,” “moderate,” and “low” suitability, respectively. Considering the prevalence of small- to medium-scale operations in South Khorasan’s mining sector, the identified zones are highly suitable for distributed PV systems (50 kW to 2 MW). These systems can operate in hybrid modes or supplement diesel generation, significantly reducing operational costs and fossil fuel dependence. This framework serves as a robust decision-support tool for sustainable energy transition in arid mining environments.