Sustainability assessment of solar drying systems: a comparative life-cycle analysis of phase-change material-based vs. cylindrical solar dryers

Abstract

Abstract Solar drying systems are becoming a popular alternative to traditional energy-based drying systems for agricultural products due to their effectiveness and reduced fuel consumption. Although the efficiency of solar drying systems has been thoroughly investigated, their sustainability has not been studied enough. This study aims to fill that gap by conducting a life-cycle assessment of two new solar drying systems built in Udaipur, Rajasthan, India. The environmental implications of an innovative cylindrical solar-assisted drying system and a phase-change material-based solar drying system were evaluated using cradle-to-gate life-cycle analysis. The study uses the ReCiPe 2016 endpoints (H) technique to calculate various aspects such as midpoint, endpoint, single score, normalization result, and network diagram for phase-change material-based solar drying and cylindrical solar-assisted drying. Results show that phase-change material-based solar drying has an average of 40% more impact on the environment than cylindrical solar-assisted drying, with a high impact found in human non-carcinogenic toxicity, mainly due to the production of phase-change materials. However, cylindrical solar-assisted drying system crossover phase-change material based solar drying in terms of its impact on human carcinogenic toxicity and fossil resource scarcity. The contribution to global warming of phase-change material-based solar drying is 13.7% more than that of cylindrical solar-assisted drying. The endpoint characterization indicates that phase-change material-based solar drying exceeds in terms of human health (40%) and ecosystem (37.04%), whereas cylindrical solar-assisted drying surpasses phase-change material-based solar drying in terms of impacts on resources, at 14%. The early drying in phase-change material-based solar drying makes up for its higher impact than that in cylindrical solar-assisted drying, which takes 3 hours longer to dry. This study offers guidance and methods for making the best choice of solar-powered dryers.