Solar Chill, a 19-year-old project that has brought solar-powered vaccine coolers with natural refrigerants (isobutane) to remote, off-the-grid locations, is poised to enter its next phase, providing food fridges.

Currently there are approximately 100,000 SolarChill A vaccine coolers installed in clinics around the world (including Africa, Asia, Latin America, and the Caribbean). One vaccine cooler can service up to 30,000 children.

SolarChill A units are also used in disaster areas such as war zones, earth-quakes, and tsunamis. For example, Doctors Without Borders installed SolarChill units in refugee camps in Chad and Sudan, and United Nations Children’s Fund (UNICEF) sent SolarChill units to earthquake-damaged zones in Haiti.

During the present phase of the project, 113 SolarChill A units have been installed in Colombia, Kenya and eSwatini (formerly Swaziland) for extensive field testing and monitoring. Through the project it was possible, for the first time, to field test and concurrently monitor online the performance of SolarChill appliances under a variety of ambient temperatures and use conditions over several months in the three countries.

The project is also successfully engaging in technology-transfer outreach to local manufacturers. Manufacturers in eSwatini and Colombia have successfully adopted the SolarChill technology and are now placing the products on the market.

At the same time, 45 Solar Chill B food refrigerators are also being installed in Colombia, Kenya and eSwatini (15 in each one). The project’s organizers are seeking funding and partnerships to support the production and commercialization of these units.

In regions without reliable electricity,  a vast amount of vaccines are spoiled each year. The financial losses are set to increase with ever-more-expensive vaccines coming on the market. The lack of reliable electricity also impacts negatively on the preservation of food supplies. Refrigeration of food in many regions is simply unavailable, resulting in extensive spoilage.

“The SolarChill Project aims to tangibly improve the quality of our environment and human health by delivering affordable, climate-friendly, lead-battery-free, solar-powered vaccine cooling and food refrigeration to parts of the world that are without reliable electrical supply,” explained Dr. Simon André Mischel of HEAT GmbH, Project Manager for the SolarChill project. The current project will be implemented until the end of 2019, although there is a possibility of extension until mid-2020, depending on the planned budget, he said.

Conceived by UNEP and Greenpeace

The SolarChill project was co-conceived in 2000 by the United Nations Environment Program (UNEP) and Greenpeace International during the 12th Meeting of the Parties to the Montreal Protocol in Ouagadougou, Burkina Faso. At the same time, the Danish Technological Institute showed interest in developing a solar powered, battery-free vaccine cooler. Other partner organizations were invited to join the project to provide much needed expertise in vaccine cooling and the use of solar technologies in developing countries.

The project was launched in early 2001. All in all, the project partners invested more than US$500,000 seed capital for research and development. The current field testing and technology transfer phase of the SolarChill Project is enabled by funding from the Global Environment Facility.

“The SolarChill project partners have no commercial interest in the SolarChill technology itself,” explained Mischel. Their sole mandate is to develop this public domain technology, make it freely available to interested manufacturers worldwide, and promote its uptake internationally.”

There are five manufacturers of SolarChill A vaccine coolers in the world: Vestfrost (Denmark); Sure Chill (U.K.) which licenses with Zero Appliances (South Africa) and Godrej (India); Haier (China); B Medical (formerly Dometic in Belgium); and Dulas (U.K.). The SolarChill team is collaborating with the Fridge Factory in eSwatini towards attaining the required WHO Performance Quality and Safety (PQS) certification for vaccine coolers.

The commercial SolarChill food fridges have not previously been widely commer- cialized, though a prototype at the Danish Technological Institute has been in operation for several years. The project has developed and published a produc- tion guideline for the development and manufacturing of SolarChill appliances.

“SolarChill B has a vast market potential as it can be used for domestic and small commercial applications in developing countries, as well as for off-the-grid recreational purposes in developed countries,” said Mischel.

How Does it Work?

In principle, the  SolarChill technology is relatively simple, explains Mischel. Solar power from two or three 60W/80W solar panels run a direct-drive R600a compressor. The compressor runs the refrigerant cycle, which in turn produces an ice bank that maintains the required temperature in the cabinet. By using thermal storage, the system stores the power of the sun in an “ice battery.” It is a solar version of the old-fashioned icebox.

A thermostat maintains the units at the required temperatures. For vaccines that is between 2-8°C (35.6-46.4°F), day and night. The optimum temperature range for perishable food storage is 3-5°C (37.4- 41°F). In low-sun situations, or with power completely disrupted, the thick insula- tion of the cabinet maintains acceptable temperatures for up to five days.

There are two original models of SolarChill, a 50L (13.2 gal) unit for vaccine cooling and a 100L (26.4 gal) unit for food refrigeration. Both models operate under the same principles. Larger SolarChill models are also available.

Working with hydrocarbons remains one of the challenges facing SolarChill, according to Mischel. “It is unlikely that existing appliance manufacturers that are not yet working with hydrocarbons in their general production line of refrigerators or freezers will be able to produce hydro- carbon SolarChill products,” he said.

However, as the use of hydrocarbons in domestic and commercial refrigerator production increases worldwide, more appliance manufacturers acquire the infrastructure and the expertise to work with hydrocarbons. “The Montreal Protocol’s Kigali Agreement for phasing down the use and production of HFCs will further stimulate the uptake of hydrocarbon refrigeration,” said Mischel.

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