Who needs electricity? Absorption coolers don't.
Absorption cooling is well-known for its reliable, silent cooling. But do you know how it works? Well, firstly, a concentrated ammonia solution is heated in a boiler and expelled as vapor. The pressurized ammonia gas then liquefies in a condenser. When supplied with hydrogen, it evaporates and in the process extracts heat from the refrigerator thus lowering its temperature. The ammonia gas then enters the absorber where it is reabsorbed in a weak solution of ammonia. Finally, this saturated solution flows back to the boiler where the whole cycle starts again. And the fact this process does not need electricity – heating from a gas flame works fine – gives users the freedom to travel off-grid!