SunDanzer has 15 years of experience with off-grid refrigeration needs, including developing the world’s first battery-free solar powered refrigerator. Winrock International is a leader in agricultural development and has more than a quarter century of experience with renewable energy based rural electrification. It has supported the installation of more than 80,000 rural renewable energy systems around the globe and has three offices in Kenya.
Due to limited electrification in rural areas, 85 percent of Kenya’s 800,000+ dairy farms do not have access to refrigerated storage and transportation. This deficiency in the distribution chain results in less than half of the milk produced reaching dairy processors. Of the milk that is processed, up to 30 percent of it may spoil without appropriate cold-storage options. Consequently, many dairy farmers and processors unnecessarily may lose significant earning potential from their operations.
Recognizing the need for affordable cold-chain technologies, SunDanzer has developed a small-scale portable cooling system tailored for use in the Kenyan dairy market. The system comprises a photo-voltaic refrigerator (PVR) that uses solar energy to cool a chest refrigerator. This uses phase-change materials—substances which are capable of storing and releasing large amounts of energy—as energy storage. SunDanzer also developed milk can blankets to retain the cold temperature as farmers transport the milk to the collection site.
This clean energy solution aims to increase dairy farm productivity and income by significantly decreasing milk spoilage. Currently, half of the milk produced cannot reaches dairy processors due to storage or transportation issues. Effective cold-chain storage lowers bacteria count and improves milk quality for consumers. These improvements can play a major role in the livelihoods of approximately one million smallholder dairy farming families in Kenya. Users have stated that the solution has provided benefits that include adding financial security to the household, cell phone charging which saved time and added income to the household, as well as food preservation.
SunDanzer completed their project in May 2018. Through their Powering Agriculture participation, SunDanzer delivered and installed 60 solar-powered milk cooling refrigerators in Kenya, as well as two units in Rwanda. They developed a second-generation, roof-mounted unit, which was determined to be a more cost-effective option than the original pole-mounted design. The system is comprised of a photovoltaic array, a chest refrigerator with phase change material lining, and water (brine) bags to transfer the heat out of the milk. The system stores energy in the freezing of the phase change material and doesn’t use batteries. Most units were installed at dairy farms, with some being deployed to farming households and camel milk processors. In their final project year, SunDanzer prototyped smaller versions of their PVR technology to better serve small farmers’ needs and investigated pay-as-you-go options to make financing and payment easier for customers. Users of SunDanzer’s refrigerators have stated that the solution has delivered many benefits, including increased financial security for households, increased food preservation, and cell phone charging capabilities (which save time and add to household income).