It works like this: the solar icemaker uses a refrigerant liquid that evaporates when exposed to the sun. The vapor travels through pipes that come into contact an absorbent material, which cools when the sun goes down. Once the slow-cooling absorbent hits 104°F, the refrigerant turns back into a liquid and its temperature drops like a rock to below freezing because of pressure differences. Put some water next to the evaporator’s exterior and, presto, ice.
Solar icemaker: get the sun to keep things cool for a change.