There are three types of solar fridges: ones that use batteries and solar panels, ones that use just solar panels, and ones that use neither batteries nor panels and are constructed from household materials.1. A solar fridge that uses batteries actually uses a combination of solar panels and lead batteries – the batteries serve as back up overnight and on sunless days. While it
can be effective, this type of solar fridge has many disadvantages. For instance, it is expensive to buy and the batteries are heavy and deteriorate quickly in hot climates. It is maintenance intensive and only lasts about three years. The batteries also need to be disposed of properly, otherwise they leak and cause lead pollution.
2. Solar-powered refrigerators that generate electricity with the help of solar panels, then use this electricity like a normal plug-in refrigerator. Although this type of refrigerator is powered by solar energy, it is not 100% eco-friendly as the cooling gases that are used in the refrigerator and the ones generated due to cooling, contribute to global warming and depletion of the ozone layer.
3. Solar-powered fridges that don’t require batteries or solar panels are better suited to developing countries, as they can be made from basic household materials. Although these fridges are technically solar powered, they rely on conduction, convection and evaporation to operate at an even 6°C.
These refrigerators work according to atmospheric temperatures – the drop and rise in the heat of the sun directly affects the rate of cooling. The greater the heat of the sun, the lower the temperature will be in the inner cylinder. Many scientists predict that solar-powered refrigerators will totally replace all electricity powered refrigerators as the most energy-efficient refrigerators.