The type of solar dryer selected for a given purpose should be matched to:

• Type of produce to be dried, the timing of harvest and possible pre-treatment.
• Quality and quantity of produce, It is important to consider that quality deterioration occurring during pre-drying cannot be eliminated in the course of the drying process.
• Seasonal variation in solar radiation.
• Drying process and drying schedule to be realised.
• Investment costs.

Costs

Unit cost of the KIRDI developed solar dryer range between $ 21.6 and $27 per kilogram rating (wet weight) for a micro unit, i.e. for 500 Kg. unit, the price is Kes. 800,000. Return on investment varies between 6 and 24 months depending on the value of the final products i.e. dehydrated fruits attract better returns on investment than dehydrated vegetables.