SolarChill.[1] is a breakthrough technology in vaccine cooling and domestic and small commercial refrigeration. SolarChill technology is relatively simple. Solar power from two or three 60 watt or 80 watt solar panels run a direct current compressor. The compressor runs the refrigerant cycle which in turn produces an ice bank that maintains the required temperature in the cabinet.  The power of the sun is essentially stored in an “ice battery”. It is basically a contemporary solar version of the old fashioned ice box.

A thermostat maintains the units at the required temperatures. The required temperature range for vaccines is between 2 and 8 °C, day and night. The optimum temperature range for perishable food storage is 3 to 5 °C.  In low-sun situations, or with power completely disrupted, the thick insulation of the cabinet maintains acceptable temperatures for up to 5 days.  The recommended ambient temperatures vary according to models. In field tests, units have operated under a wide range of ambient temperatures; from +10ºC to +42ºC. New models are underway for 48ºC ambient temperatures.

There are two models of SolarChill: SolarChill A, a 50 liter unit for vaccine cooling and SolarChill B, a 100 liter unit for food refrigeration. SolarChill B is for domestic and light commercial use. Both models operate under the same principles.  There are plans for developing larger SolarChill models.

While SolarChill A is primarily for use in off-grid regions of developing countries, SolarChill B has market potential in off-grid regions of all countries (e.g. recreational cottages). The vaccine cooler model is already commercialized where as the food refrigerator model is still in the R&D phase.

A list of available SolarChill products is available here.

[1]The SolarChill Project partner organizations are the Danish Technological Institute (DTI), the German Government Development Agency (GIZ ProKlima), Greenpeace International, Program for Appropriate Technology in Health (PATH), United Nations Environment Programme (UNEP), United Nations Children's Fund (UNICEF), World Health Organization (WHO), and the World Bank. SolarChill Industry Participants include Vestfrost and Danfoss. Please see “Contacts” for the names and contact information of individual representatives.