Sustainable solution for water crisis in Indian coastal district: A multi-criteria approach to evaluating solar PV powered reverse osmosis desalination

Visakhapatnam, poised to become the executive capital of Andhra Pradesh, is confronting escalating population growth and water scarcity challenges. With over 19 lakh residents and an 11.96% growth rate, the city’s water demand is expected to outstrip its current supply capacity. The Greater Visakhapatnam Municipal Corporation relies on diverse water sources, but encroachments on water bodies and industrial pollution exacerbate the scarcity issue. Against this backdrop, desalination emerges as a sustainable solution, leveraging the city’s extensive coastline. This study explores the technical, economic, environmental, social, and political dimensions of implementing a solar-powered Reverse Osmosis (RO) desalination plant in Visakhapatnam. While various desalination methods exist, solar-powered RO is highlighted for its ecological sustainability, utilizing abundant and renewable solar energy. The study employs the Multi-Criteria Decision-making Approach (MCDA) to comprehensively evaluate the proposed solution. The application of fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) aids in identifying the optimal solution under uncertain conditions. Furthermore, a graph theory and matrix approach are introduced to analyze the decision-making problem. The attribute digraph visually represents the relationships between different criteria, while the permanent matrix quantifies the relative importance of these criteria. The study location selection process involves linear normalization and a permanent matrix computation, ultimately ranking Chinna Rushikonda as the top choice for implementing a solar photovoltaic-powered RO desalination plant. The integration of MCDA, fuzzy TOPSIS, and graph theory provides a comprehensive and robust methodology for decision-making in complex projects, ensuring sustainable and well-informed choices.