Crop dryingisessentialforpreservationinagriculturalapplications.Itisperformedeitherusingfossil
fuels inanartificial mechanicaldryingprocessorbyplacingthecropundertheopensun.The first
method iscostlyandhasanegativeimpactontheenvironment,whilethesecondmethodistotally
dependent ontheweather.Bycontrast,usingasolardryeriscomparativelycheaperandmoreefficient.
Some solardryersrunwithoutelectricalgridpowerorfossilfuels.Thispaperpresentsthestateof
variouskindsofsolardryersthatarewidelyusedtoday.Theindirect,direct,andmixedmodedryersthat
haveshownpotentialindryingagriculturalproductsinthetropicalandsubtropicalcountriesare
discussed. Asidefromidentifyingtheactiveandpassivemodesolardryers,wealsohighlightthe
environmentalinfluence onsolarenergy(harnessing)thatplaysavitalroleinthesolardryingsector.
This paperalsopresentstherelatedtechnologiesthatcanhelpimproveexistingsolardryers.