It might seem a bit contradictory to use solar power to create cold and ice for farmers and fishers in Africa. But it is becoming more common than it used to be.
By cooling and drying fish, as well as vegetables, farmers and fishermen can avoid spoilage and bring more products to the market. Preserving food also means they can sell products off-season, creating a secure income base and generating higher revenues.
In Kenya, the SolCoolDry system is a 15 kWp photovoltaic system that feeds electricity into a three-phase, battery-supported stand-alone grid, which powers the ice machine and cold room for fishers. Up to 1500 kilograms of ice can be produced within 24 hours. Excess solar power is fed into batteries with a total storage capacity of 19.2 kilowatt-hours.
The system also has two solar tunnel dryers in which air is heated and distributed by fans over the dry goods throughout the day. In order to be able to continue drying throughout the night, one of the tunnel dryers contains heating pipes, supplied with heat from a 12 square meter flat-plate collector and 2000-liter hot water storage tank.
The idea was to create a system local people can operate on their own, says Dr. Alexander Morgenstern, who is the project manager. Fraunhofer ISE worked with Innotech Ingenieursgesellschaft mbH, Kenya Industrial Research and Development Institute, Kenya Marine and Fisheries Research Institute, and the Technical University of Mombasa on the project. It was funded by the German Federal Agency for Agriculture and Food.
Since August, the Beach Management Unit, an association of fishermen, mangrove planters, farmers, beekeepers and seaweed farmers, has been jointly responsible with KIRDI for operating the system. User fees for the dryer and sale of the ice will finance plant maintenance. Fraunhofer will remotely monitor the performance of the plant with a monitoring system and in October 2022, will hold a training workshop with the local partners to discuss how to further develop the system.
Cold Hubs photo
In Nigeria, solar-powered cold rooms and cold trucks help small rural farmers get their produce safely to markets and extend its shelf life while there. Nnaemeka Ikegwuonu introduced ‘clean cooling’ to his country when he created ColdHubs in 2015.
The solar-powered walk-in cold rooms extend the shelf life of fruits and vegetables from two to 21 days, using a subscription model. In 2021, more than two million crates of fruits and vegetables were stored in 54 company cold rooms and 18 cold rooms managed by small and medium-sized enterprises, saving about 62,700 tons of produce from spoiling.
Two solar-powered refrigerated trucks now pick fruits and vegetables directly from farms and deliver them to markets, and ColdHubs plans to build cool rooms in hard-to-reach communities where farmers can store harvests while waiting for pick up. Ikegwuono wants to provide at least a 100-ton storage cold room to all 36 states, up from the current 3-6 tons, and to build a solar-powered fruit and vegetable market.
And in Kenya, Sokofresh provides farmers with access to cold storage – and has just won a 2022 Ashden Award for its work. Here is how it describes what it does:
“50% of all horticulture produce in Kenya fails to make it to market as a result of an informal & unreliable supply chain. Farmers frequently lose quality produce due to their inability to store it for longer than a day. As a result farmers earn less, logistics costs are high and vast quantities of food are wasted.
“SokoFresh offers farm level cold-storage as a service and a digital market linkage platform to seamlessly integrate small and medium scale farmers into professional value chains. With its mobile cold storage solution and pay as you store business model, it gives farmers, traders and exporters a risk-free opportunity to safeguard the quality of their produce and increase their bottom-line.”