Life cycle sustainability assessment of box solar cooking technologies: Comprehensive comparative analysis with traditional fuels

The cooking sector contributes significantly to global greenhouse gas (GHG) emissions, with traditional biomass and fossil fuels causing severe environmental and health impacts. This study presents a comprehensive Life Cycle Assessment (LCA) and a novel Selection Index (SI) framework to evaluate the sustainability of traditional cooking fuels, Coal, Kerosene, Firewood, Dung Cake, LPG, Induction, and advanced solar cooking technologies: Box Solar Cooker (BSC), Parabolic Box Solar Cooker (PBSC), and PCM-integrated BSC (BSC-PCM). The LCA quantified energy, economic, and environmental (EEE) performance over a five-year operational period, incorporating upstream, core, and downstream life cycle stages. Results indicate that LPG delivers the highest net energy surplus (44.9 MJ) among traditional fuels but still emits ∼3,089 kg CO 2 , whereas BSC-PCM achieves a positive carbon balance (+340 kg CO 2 offset) with minimal embodied energy (<0.7 MJ). Economic analysis revealed that Induction cooking offers the best net savings among conventional systems (₹87,253), while solar systems yield consistent surpluses (₹2,132–₹4,332) with zero operational fuel cost. The proposed SI, incorporating logarithmic scaling, weighting factors, and sensitivity adjustments, ranked BSC-PCM (0.72) highest in sustainability, followed by PBSC (0.70) and BSC (0.65), with all traditional fuels scoring negative. Sensitivity analysis confirmed robustness under varying weighting scenarios, and scenario modelling demonstrated adaptability to diverse climatic and socio-economic contexts. The integration of LCA with a flexible SI framework provides a transferable methodology for policy-makers, aligning with SDG 7 (Affordable and Clean Energy), SDG 13 (Climate Action), and SDG 3 (Good Health and Well-being), and offering a decision-support tool for accelerating clean cooking transitions.