The drying method must be customised for the product to be dried and to the available sources of energy, otherwise it can be very expensive. Chosing the proper and most economical drying method for each situation is very difficult, usually considered an art.
The methods and devices employed in drying are very varied, from a simple tarp on which products are just placed under the sun, to fluid bed driers in computer-assisted dying systems in factories. Often the driers are bulky and require a lot of space for installation.
The cost of energy is the largest expense with drying; this is why solar driers are an attractive option.