Wamala - Solar powered cooling for Ugandan farmer's milk


Farmers in rural areas of Uganda lack access to electricity; the consequence is a lack of cooling options for their produce causing low durability and transportability. Productivity and income of the farmers and population health are negatively impacted. 

Specifically, “evening milk” is lost – it spoils overnight as it cannot be cooled. These post-harvest milk losses amount to about 40 % in Ugandan communities.  


The solution: 

Based on an innovation by the University of Hohenheim, Wamala developed a mobile solar-powered cooling system that produces ice cubes. The core idea is to enable farmers to cool their milk with ice cubes, which are produced with electricity generated by solar panels. Ice cubes allow the cooling of large quantities of milk, without the need for large cold storages and can be flexibly used during transport. Wamala enables the farmers to operate and maintain the off grid system themselves. The system is not restricted to cooling milk, but can be applied for the conservation of other produce such as fish. 


The business model: 

Wamala Energy receives a share of the additional revenue that the farmers earn due to the cooling system keeping the milk fresh longer and enabling cooled transportation.The market can be extended to many other farmers and producers, such as fishers. 


Current status: 

In May 2019, Wamala Energy was founded as a corporation in Uganda. In July, the market pilot started with two farmers. With a total of 100 farmers as customers, the business will be profitable. Within a cooperation with a local NGO, capacity building e.g. with technical trainings are currently being conducted in Uganda. The team is already in contact and preparing a cooperation with a network of 400 farmer cooperatives. In the first pilot month, already 1.000 litres of milk have been cooled.



  • 30.000 € external investment from e.Ray

  • Market potential: several hundred farmers cooperatives exist in Uganda; model can be extended to fishers and others producing food which needs to be cooled during storage and transport


Expected impact: 

  • Increasing milk production by 40 litres per day for each farmer 

  • Increasing revenues of the farmers by enabling them to sell their milk at higher quality standards and using the evening milk for selling the next morning

  • Improving productivity of Ugandan farmers by improving the milk value chain 

  • Impacting population health by improving milk quality  

  • Creating new jobs and improving the livelihood of the community 


The team: 

e.Ray Europe, Uganda Wind Association, Uganda HydroPower Association

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