Solar refrigeration sounds like an oxymoron. How can the sun be used to keep something cool – or even frozen?! But solar refrigeration is one of the oldest and most popular applications for solar energy. At our office in Arizona, we enjoy a 165 liter refrigerator powered entirely by one 85w solar module. The battery absorbs enough energy each day to keep our refrigerator running and our food and drinks cold!
Most solar refrigerators on the market today use a very well-insulated cabinet and R-134a refrigerant circulated by a Danfoss compressor run from a 12v or 24v battery. They tend to be much more efficient than the average AC refrigerator but are also smaller and more expensive. The actual power consumed will vary greatly with number of door openings, amount of warm products added each day, and the ambient temperature.
Many customers ask for solar ice-making machines. While any freezer can make ice, the cost of powering a commercial ice-making machine with solar would probably be prohibitive. That being said, one should not consider our freezers as ice-makers.
Since refrigerators/freezers are bulky but relatively light, the cost of transportation is a major component of their cost. We find that shipping refrigerators to Africa by air effectively doubles their price. So we recommend either adding these to a container bringing other items or bringing in a full container. Once the units are on the ground in Africa they tend to sell quickly!