Fuzzy multi-criteria approach for rooftop photo-voltaic site selection: a case study in Gujarat

India has positioned itself as a global leader in solar energy generation as part of its commitment to sustainable development. Among various renewable energy models, the rooftop solar segment has seen considerable advancement and is now regarded as one of the most dependable and eco-friendly options. However, the widespread adoption of rooftop solar systems at the household level remains a challenge due to multiple factors, such as uncertainty in the decision-making environment and the complex characteristics of decision criteria. Despite the importance of strategic planning for such installations, studies focusing on selection criteria for rooftop solar implementation at the district level in India are relatively scarce. This research focuses on four districts in the state of Gujarat to evaluate the suitability of rooftop solar deployment. Initially, relevant criteria were identified for each district based on previous literature. Subsequently, five decision-makers provided assessments of the importance of these criteria using linguistic variables. A fuzzy multi-level multi-criteria decision-making (FMLMCDM) technique was then applied to rank the districts based on their readiness for door-to-door rooftop solar system implementation. This study introduces an innovative FMLMCDM framework that merges hierarchical fuzzy assessment with expert-based linguistic evaluation to determine the most appropriate districts for rooftop photovoltaic (PV) installations in Gujaratan approach not previously utilized in this context.