Dec. 4, 2023, 7:48 a.m.

Agriculture is the main economic activity in Rwanda, employs 62% of the working population and represents about a 23 % of the National GDP (MINAGRI, 2022). 75% of Rwanda’s agricultural production comes from smallholder farmers, of which 70% are women. Despite that agricultural productivity is still low, there is also high post-harvest loss particularly in fruit and vegetables by which more than 40% of production is lost before reaching the end user (RAB, 2018). To handle this, some strategies were introduced to help farmers reduce post-harvest loss including among others, cold rooms. However, farmers are claiming that the conventional refrigeration technologies are expensive to buy and to run due to high electricity consumption and costly maintenance. Furthermore, beside of being expensive, most of conventional cooling systems uses hydrochlorofluorocarbon (HCFCs), Chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs) as refrigerants; the ozone depletion and global warming gases. For instance, as indicated by BBC, HFCs and HCFCs’ capacity to warm the atmosphere, measure as global warming potential, is thousands of times greater than carbon dioxide, with some being up to 13,850 times more potent.

It is in the above context that AGRIRESEARCH UNGUKA Ltd, a youth-led company that does market-oriented agricultural research and extension services, based in Musanze district, in partnership with Kilimo Trust, under Good Food for Cities (GFCs), a 5-years initiative (2022-2026) implemented in Rubavu District, in the Western Province of Rwanda, developed a game-changer eco-friendly and cost-effective postharvest technology that uses no electricity in cooling. It is called Zero Energy Charcoal Cooling Chamber.

How Does it Work?

Zero Energy Charcoal Cooling Chamber is a natural refrigeration system that use the principle of "Evaporative cooling". In fact, it uses water as refrigerant, charcoal and air. When the warm air enters the walls, it comes across with the layer of moist charcoal resulting in water evaporation. As water in the charcoal evaporate, the heat is removed from the room resulting in cooling.

Abdu USANASE, CEO of AGRIRESEARCH UNGUKA Ltd during his follow up visit to the members of KOTIBANYA Cooperative in Rubavu district, to assess the performance and challenges farmers faced while using Zero Energy Charcoal Cooling Chamber.

The installed cold room has the capacity of storing 3-5T of vegetables and fruits with temperature ranges between 10-15oC and 90% of Relative humidity. Using this post-harvest technology facility, farmers can keep their vegetables fresh up to three weeks. For instance, carrots, tomatoes, and beetroots can be kept freshy to three weeks within the cold room. Leafy vegetables such as Amaranthus, broccoli, celery, spinach, Suisse card, etc. can be stored two to three days.

In fact, as said by cooperative president HABUMUGISHA J. D’Amour, this cold room is a sustainable solution to the vegetable post-harvest losses experienced by cooperative members who not only grow but also sell vegetables at Bazirete market. This cooperative whose 200 members of about 95% are women said that the losses was high especially in case the yield is high or produces were not all sold. In some case, the buyers would change their mind or the plan like the day to buy the vegetables resulting in big loss due to lack of suitable way to preserve our produces one of cooperative member said. For instance, they said that at least three in fifteen sacks of couli flowers are lost at every harvest. This charcoal cooler is easy to buy, to run, and to maintain. Consequently, we undoubtedly believe that it will help us to reduce post-harvest loss hence increase our income. KOTIBANYA president concluded.

AGRIRESEARCH UNGUKA Ltd produces zero energy cooling chambers of different storage capacity. From the one that can be used at home to preserve fruits and vegetables of up to 30 Kgs to the one of 3-5 Tons that can be used by exporters, cooperatives and other big farmers. These cooling chambers are an ideal in removing field heat at low price. In case you want yours, kindly reach out to AGRIRESEARCH UNGUKA Ltd at their head office located in Musanze district, Busogo sector or call them at +250791728059 or email at


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