A team of engineering students from San Jose State University has designed an ice maker that leaves no carbon footprint.

Places where electricity has been a luxury item beyond the reach of local pocketbooks could benefit from such amenities as solar refrigeration if the device could be commercialized.

Unlike ice-making machines which need electricity for the compressor, this solar-powered ice maker uses refrigerant liquid that evaporates when it's exposed to the sun, and the whole thing works without any moving parts. All of the systems are sealed, so barring a leak, they would never need replenishing.

The process uses refrigerant liquid that turns to vapor as the sun heats up during the day. The vapor travels through pipes that come into contact with an absorbent material, cooling when the sun goes down. But once the absorbent material heats up to 104°F in the sun, the refrigerant becomes liquid again, and that drops the temperature below freezing because of pressure differences. By simply putting water next to the evaporator this device turns the water into ice.

Via San Jose State University