Mohammed Bah Abba is a Nigerian teacher, from a family of pot-makers, who became famous after receiving the $75,000 Rolex Award for Enterprise for his pot-in-pot cooling system for refrigeration.

The Pot-in-Pot system consists of two pots, a smaller earthenware pot nestled within another pot, with the space in between filled with sand and water. When that water evaporates, it pulls heat from the interior of the smaller pot, in which vegetables and fruits can be kept. In rural Nigeria, many farmers lack transportation, water, and electricity, but one of their biggest problems is the inability to preserve their crops. With the Pot-in-Pot, tomatoes last for twenty-one days, rather than two or three days without this technology. Fresher produce can be sold at the market, generating more income for the farmers.

The project is part of the Design for the other 90% exhibition.

A smart product locally manufactured using local resources. Easy to manufacture and effective, it rappresents the proper way to design for people living in poor countries.