Crafted by a potter named M Sivasamy, this clay pot was designed to help keep produce cool for days.
He made a cylindrical pot made out of clay with a tap on one side and an outlet to pour water on the other side. A smaller pot fits inside the bigger one where you can place your vegetables which is then covered with a lid. The technology is simple — the water in the pot remains cool keeping the vegetables fresh and cool. - BetterIndia
For places with no or limited electricity, this could help immensely. Especially considering terracotta(earthenware) clay is almost used worldwide.
More Info:
Yep, these are brilliant for dry climates, but for humid areas you'd need something else or a small power station (check out gearscouts.com if you need one that's actaully efficient with LFP batteries).