Who, What & Where

  • Phaesun GmbH in cooperation with University Hohenheim & Solar Cooling Engineering UG founded the “SelfChill Team”
  • Improving Milk Value Chains through Solar Cooling
  • Kisumu, Nairobi, and Siaya, Kenya

The Company

Phaesun has been specialising in the sale, service and installation of off-grid photovoltaic and wind power systems since the foundation in 2001. As one of the world’s leading system integrators of off-grid energy systems, Phaesun offers products of all reputable manufacturers of this trade. International project management, purposeful training courses for customers and technical support complete the range of services offered.

The Challenge

Smallholder dairy farms are the major providers of marketed milk in Kenya. Due to the low individual production levels, farmers are usually associated with cooperatives. Dairy cooperatives are responsible for collecting the raw milk from the members to supply bigger volumes to dairy plants or the market. These cooperatives are often constrained by minimal hygienic standards and the lack of cooling systems leading to high microbial contamination of the milk. As a result, 20-30% of the milk is estimated to be lost.

Renewable Solution

A baseline study to interview farmers and to train them in the use of the technolo­gy took place. University Hohenheim and University Strathmore conducted technical training to transfer knowledge about solar cooling technologies to local technicians, solar installers and other stakeholders.

Phaesun together with the University of Hohenheim has conceptualised a solar milk cooling system based on the use of con­ventional milk-cans and adapted DC re­frigerators. The milk cooling system called Milky Way consists of the Steca DC Freez­er PF 166, four solar modules of 150Wp, two 82 Ah batteries, milk cans, ice cups, electronics and installation material. This technology assures the preservation of milk quality from the farm to the main col­lection centre or market and shows great potential to make the dairy value chain more efficient by using clean energy.

This technical concept was optimised by the University’s spin-off company, Solar Cooling Engineering (SCE) and Phaesun. The new innovative SelfChill strategy offers a modular solution that can be adapted to different farm sizes and milk collection systems. In the new concept, the produced cold is stored in an ice reservoir, the so-called water chiller, which can be either used to cool milk cans or to cool entire milk tanks.

Project Financing and Costs

The project was funded through Powering Agriculture by GIZ and BMZ. To prove eco­nomic sustainability, the objective was to demonstrate that dairy farmers appreciate the cooling of milk and can pay a monthly rate for the service. The implemented payment model proved to be successful and confirmed the great potential of this inno­vative approach. At the end of the project, the ownership of the systems was trans­ferred to the farmers.

Project Outcome

Under the project, about 10 farms and co­operatives have been equipped with solar milk cooling systems with a capacity of 60 l / day each, thus reducing milk losses by approximately 25%. That means that a minimum of 50 people could increase their income.

As the cooling systems completely rely on solar energy, no CO2 emissions are pro­duced while using the systems. Another important factor to guarantee a sustain­able system is the use of a natural refrig­erant with low global warming potential.

Next Steps

In the course of the project, it became ap­parent that there is also a great demand for medium-scale milk cooling systems. As a result, SCE in cooperation with Phaesun developed the modular SelfChill® concept. Local materials can be used, thus increas­ing local added value and the systems are pay-as-you-go compatible, creating attrac­tive business models even in regions with low purchasing power. In the latest proj­ect “PV-Cool Kenya”, which started in July 2020, a cold room for agricultural products (20m3), a milk chiller (560 l) and an ice machine (50 kg/day) will be installed in Kenya demonstrating the potential of the SelfChill® concept.