Our solar powered vaccine Refrigerator combines several "breakthrough" features.
No batteries: The unique feature of the Fridge is that the energy of the sun is stored in ice instead of in batteries. An ice compartment keeps the cabinet at desired temperatures during the night. The key to the technology is the use of a direct current (DC) compressor instead of the standard alternating current (AC) compressor used in normal refrigerators, or in other solar coolers.
Thus, the sun's energy is captured by the solar panels and converted to direct current electricity. The DC current starts up the compressor which then runs the refrigeration cycle. Ice is produced in an ice storage compartment. The cool air is then circulated by convection and by a fan into the cabinet and maintained at the desired temperature by a thermostat.
Environmentally friendly: It incorporates environmentally friendly Greenfreeze refrigeration technology. Greenfreeze was developed and made freely available to the world by Greenpeace in the early 1990s. Greenfreeze utilizes hydrocarbons for the insulation foam and the refrigerant cycle, and thus bypasses the reliance on ozone layer depleting and potent global warming fluorocarbon s, such as HCFCs and HFCs.. This is the first ever application in the world of a direct current hydrocarbon compressor.
Versatility: A converter enables this fridge to be powered by multiple sources of energy. In addition to plugging into the electrical grid, this solar fridge can also run on independent sources of power, such as solar, wind, biomass and diesel generation.