Evolution and Advancements in Solar Drying Technologies: A Review

Solar drying methods are used since long times and efforts are made to utilize these non-replenishable sources of energy in more effective and efficient manner. From old times, the use of solar energy is limited to very few applications. But as time passed, solar energy use has evolved to vast areas for drying industrial products, edible goods and agricultural products. Recently, the solar drying systems are integrated with other renewable and non-renewable sources of energy to have more reliable systems. This paper reviews various technologies and different areas of applications that are linked up with solar drying systems. Study of various technologies already used in solar drying field and how these evolutions give way to new ideas and more competitiveness to solar energy is carried out. A comparison of other non-renewable sources of energy like electric energy, energy from burning of coal and natural gas, etc with solar energy is evaluated. Future advancements can be carried out in the solar drying area by working on waste energy management techniques and coupling these too drying systems. Methods used for drying products other than solar drying also be incorporated with solar drying to study the drying product behaviour.