Sustainability assessment of hybrid active greenhouse solar dryer integrated with evacuated solar collector

Abstract

Environment and Economy are the two important pillars of sustainability. In this paper, the economic viability and environmental impact of the novel greenhouse dryer with an evacuated solar collector are calculated. For this analysis, tomato is dried inside the dryer as it is a high moisture crop that requires a faster drying rate otherwise it starts giving a bad odor and gets contaminated. The hybrid active greenhouse dryer is developed especially for drying high moisture agro and non-agro-based produce. Evacuated tube solar collector is integrated with the dryer that supplies the hot water to the heat exchanger kept inside the dryer. The hot water flowing inside the copper tubes of the heat exchanger transfers its heat to room air through convection and to crop through conduction. Hence the higher room temperature and faster moisture removal rate are obtained. Tomato slices have been dried from 94.6% (wb) to 10% (wb) moisture content in 10 h. The developed dryer can produce 261 kg of dried tomato annually and its payback time is only 1.73 years which is very less as compared to its life of 30 years. In its entire lifetime, the dryer will mitigate 169.10 tonnes of CO2 that prove its suitability from a sustainable point of view.