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The horticultural industry is an important economic sector in the developing world. New innovations are key to horticulture's success. The horticultural industry is founded on an intensive interaction between governmental research institutions and private companies. Knowledge transfer is crucial.
Cold Storage for Developing World Farmers
Published on 6th Apr 2011
While postharvest losses in the U.S. are roughly 12%, it is 
estimated that these losses can be as high as 80% in many developing-world countries. For smallholder farmers eking out an existence on the tattered edges of our global economy, watching so much of their hard work spoil on the way to the paying consumer is particularly disheartening. Postharvest losses erode the farmgate value of their produce and reduce the amount of fruits and vegetables available to the surrounding populace, who typically suffer from high rates of micronutrient deficiency.
High temperatures are the main cause of postharvest loss in the developing world, and that makes postharvest cooling the most effective way of reducing losses. The need for temperature control is especially acute because ambient temperatures are often above 30°C, which can accelerate the deterioration rates of produce by a factor of twenty. However, cold storage can be prohibitively expensive. Conventional coolrooms and transportation systems employing mechanical refrigeration cost thousands of dollars and are very difficult to maintain in developing countries; unreliable electricity also thwarts cold storage possibilities. For resource-limited farmers, conventional coolrooms are economically and practically infeasible.
The Coolbot is the answer!
The Coolbot provides inexpensive cold storage to developing-world farmers. The Coolbot is a small black box that is wired into a standard air conditioner. It overrides the air conditioner’s temperature gauge and tricks it into working harder, thus turning an insulated room and an air conditioner into a coolroom. To prevent the fins from icing up and disrupting airflow, the Coolbot monitors the fin temperature and stops the compressor when ice builds up. The ice on the fins continues to cool the air until it melts and the compressor turns on again.
The Coolbot reduces the cost of cold storage from thousands of dollars to mere hundreds, making it a viable option for developing-world farmers.
Through USAID funding, Horticulture CRSP researchers investigated appropriate methods of delivering the Coolbot technology to farmers. They examined a range of locally available materials that can be used to insulate the coolrooms, including feathers, straw bales and shredded paper. They also evaluated the use of solar panels to power the system in order to solve the problem posed by unreliable electricity. Finally, the Horticulture CRSP researchers designed a passive transportation container that will keep produce cold during its journey to local markets. USAID funds enabled collaborating scientists from Uganda, India and Honduras to travel to California to work with UC Davis researchers on the Coolbot and postharvest issues. Three scientists, Julia Gomez, Gloria Androa, and Neeru Dubey, participated in the UC Davis postharvest short course and received training in Coolbot operation and coolroom construction. Julia Gomez returned to Honduras and began working with a women's cooperative that produces tropical flowers for export. The team identified a room at the packing station that was insulated and fitted with the Coolbot system. Neeru Dubey built a coolroom in India that employs a sandwich construction model with rice hulls as the insulating 'material' in the mud-brick sandwich. Gloria Androa and her local partners identified a site for the Coolbot in a village in Uganda and determined that papyrus, already used in domestic construction, is the best insulation material for their coolrooms. In Honduras, Uganda and India, the Coolbot is proving to be an effective means of bringing farmers together to reduce postharvest losses.
High temperatures are typical in most developing countries. Low temperatures are an elusive goal for the local farmers. This gulf between high and low temperatures in developing-world horticulture leads to high postharvest losses. As Julia, Gloria, and Neeru have demonstrated, the Coolbot bridges that gulf by providing farmers with inexpensive cold storage opportunities. The Coolbot is an excellent example of a leap-frog, sustainable technology that increases the profitability of smallholder farms and improves the lot of rural communities.
Michael ReidPeter ShaplandMark Bell