Comparative energy-exergy and economic-environmental analyses of recently advanced solar photovoltaic and photovoltaic thermal hybrid dryers: a review

Solar dryers are equipped with photovoltaic panels to increase energy efficiency, profitability and independency on nonrenewable energy. Also, these dryers need to be assessed from economic, environmental, and energy-exergy perspectives to determine whether the devices are cost-effective and feasible on a large scale. This study has performed energy, exergy, economic, and environmental evaluations on the newest solar dryers equipped with photovoltaic panels and photovoltaic thermal collectors. In this regard, solar dryers with hot air collectors, concentrating solar dryers, photovoltaic thermal dryers, infrared, greenhouse, and heat pump solar dryers equipped with photovoltaic panels and photovoltaic thermal collectors were investigated. Then, studied dryers were categorized. Initially, this classification was carried out regarding the dried products and subsequently, their economic-environmental and energy-exergy were compared. Despite the short drying time of infrared and heat pump solar dryers, these dryers’ construction and energy costs are relatively high. Comparatively to other solar dryers, concentrating solar dryers have high energy efficiency and short drying times.