Solar Drying Techniques for Crops

ENTRY DATE: 18.04.2015 | LAST UPDATE: 18.04.2015

CATEGORIES:

  • Agriculture
  • Processing Techniques

TECHNOLOGIES MATURITY:

Applicable immediately

Technology Owners:

  • Early research by CIAT (Centro Internacional de Agricultura Tropical) on how to best use mesh trays
  • Preliminary chipping and drying trials were conducted at Fiji’s Ministry of Agriculture. Tests were carried out on a new design of slicing machine and a prototype solar drier, both entirely developed in Fiji by the Central Workshop (UNIDO funded) of the Ministry of Economic Planning and Development.

Needs Address

  • Food security
  • Household Security

Adaptation effects

Allows locally available crops to be used instead of imported crops leading to less dependence on imported crops.

Overview and Features

Solar drying systems harness energy from increasing temperature to process crops for alternative livelihood uses

Figure 1: The sequence of the processing line for Cassava (Source (Mattel, 1985))

Figure 2: Mesh Drying Plant Layout (Mattel, 1985)

Figure 3: Mesh Drying Plant Layout (Mattel, 1985)

Cost

  • Equipment
  • Labour
  • Training
  • Drying equipment in Vanuatu has been valued at $300 per unit
  • The following cost refers to a mesh drying plant in Fiji with 200m of drying surface and a processing throughput of 2.5ton of fresh tubers needed to produce 1 ton of dried chips:
  • Equipment cost, including slicing machine, washing drum, drying platforms and miscellaneous: US$3000
  • Processing costs: labour (27.5 man-hours) and fuel (1 gallon): US$16.5
  • Maintenance and depreciation cost: US$ 34 per month

Energy source

Solar

Ease of maintenance

Equipment requires ongoing maintenance 

Technology performance

Farmers engaged due to technology’s simplicity

Considerations

  • The site should be on an elevated area and far from anything that may constitute a barrier against wind and sun.
  • Sun drying depends on weather conditions
  • Careful prior planning has to be done taking into account depreciation costs, reimbursement of initial investment and volume of crop

Co-benefit, suitability for developing countries

  • Reduces energy use from non-renewable sources where artificial drying technique requiring energy is utilised
  • Allows a low capital outlay with minimum labour input for equipment construction
  • Uses cheap, locally available materials and easy to build but durable equipment
  • System is flexible to changing supply of crop
  • Accessibility, remoteness and inadequate transport to the urban market and the lack of a local fresh market need to be considered
  • Reduced the injustice, discrimination, and abuse against minorities

Information Resources

FAO, 1985. Expert Consultation on Planning the Development of Sun drying Techniques in Africa. Available from: http://www.nzdl.org/gsdlmod?e=d-00000-00—off-0fnl2.2–00-0—-0-10-0—0—0direct-10—4——-0-1l–11-en-50—20-about—00-0-1-00-0–4—-0-0-11-10-0utfZz-8-00&cl=CL3.20&d=HASH01dfcb9fd65bcd43c5ec3617.6.3&gt=1 [15 November 2014]