Advancing sustainable aviation by integrating renewable solar energy into unconventional airport spaces using a spherical fuzzy CRITIC–RATGOS approach

The integration of renewable energy into airport operations is critical as the aviation sector advances toward sustainability and carbon neutrality. Solar energy stands out as a scalable, cost-effective solution that can seamlessly integrate with existing airport infrastructure. While conventional applications such as rooftop and ground-mounted photovoltaic (PV) systems are common, the potential of unconventional solar solutions in underutilized airport spaces remains largely unexplored. This study addresses this gap by prioritizing solar energy alternatives for non-traditional airport spaces using a Spherical Fuzzy CRITIC-RATGOS framework. Istanbul Airport, with its high energy demand and expansive infrastructure, serves as the case study. A panel of eight experts evaluated five key criteria: economic feasibility, environmental impact, technological efficiency, scalability, and operational reliability. The analysis identified solar canopies over parking areas (SC-PA) and solar farms on unused land (SF-UL) as the most viable alternatives due to their economic attractiveness, scalability, and minimal operational disruptions. Floating solar panels on reservoirs (FS-WR) also showed strong potential by conserving land and offering environmental benefits, albeit with additional regulatory considerations. Lower-ranked options, such as solar-integrated pathways and runways, face challenges related to safety, cost, and aviation regulations. A scenario-based sensitivity analysis confirmed the robustness of the rankings, reinforcing the reliability of the proposed model. These findings offer actionable insights for airport authorities and policymakers, emphasizing the importance of multi-layered solar strategies, regulatory incentives, and financing mechanisms like power purchase agreements (PPAs). By utilizing underused spaces for solar deployment, airports such as Istanbul Airport can significantly reduce grid dependency, improve energy resilience, and align with global sustainability targets.