Comparative evaluation of renewable energy investments: a multi-criteria decision-making approach

• Seven MCDM methods rank renewable energy options. • Hydropower outperforms other renewable investments. • Shannon entropy weights criteria objectively. • Comparative analysis identifies the optimal decision method. • Guides policymakers in sustainable energy investments. Ghana’s pressing need for a sustainable energy transition in the face of increasing demand and climate change drives this study, which aims to objectively assess and prioritize renewable energy investment options for the country. The analysis uses secondary data collected from national energy reports, government databases, and peer-reviewed literature to compare five main renewable energy sources: solar PV, solar thermal, hydropower, wind, and biomass. Thirteen economic, technical, social, and environmental criteria are weighted objectively using the Shannon entropy method. Seven Multi-Criteria Decision-Making (MCDM) models—SAW, TOPSIS, ELECTRE, VIKOR, ARAS, COCOSO, and MARCOS—provide a robust validation of results. Findings consistently show hydropower as the optimal choice across all models (e.g., SAW: 0.801, TOPSIS: 0.895), with solar PV as a strong alternative. “Technological maturity” is identified as the most influential criterion. The study’s framework delivers actionable recommendations, including prioritization of hydropower in national energy planning and promotion of solar PV investments to diversify Ghana’s energy supply.