The Pot-in-Pot Refrigerator
Created | Updated Oct 4, 2010
Once in a while, someone has a brilliant idea that is so breathtakingly simple that it has people muttering Why didn't I think of that? under their breath. Many of these ideas get transformed into inventions: the electric lightbulb and the World-Wide Web are two that have contributed to the ongoing transformation of affluent society.
Invention through Necessity
It's rare that an invention is aligned with the concerns of the other two-thirds of humanity, who don't even have electricity, let alone a light socket or a 'phone connection. What use is being able to download ringtones to a rural African farmer, when he's concerned where his next meal is coming from? Ask him which technological marvel he'd like to have and he'd probably settle for a refrigerator to enable him to keep his harvested food fresh.
Thanks to a Nigerian engineer, the farmer now has one fewer worry. Professor Mohammed Bah Abba came from a family of potters, and as a child had been intrigued by the way that water seeped through the pot to evaporate on its surface. He also knew that life in rural Nigeria was hard, with many people eking out an existence by subsistence farming. Surplus food could not be stored by the family, but instead had to be sold immediately on town streets, mainly by the female children who, in a more industrialised country, would have been at school.
Creating a Solution
Professor Abba (who is also a staunch advocate of women's rights) decided to do something about this, and did so with a particular flourish of genius. He invented a refrigerator that consists of two concentric stoneware pots separated by a layer of wet sand. Food is placed in the central pot, and water is poured into the sand to keep it moist. A damp cloth keeps the interior of the pot away from the hot air.
As the temperature rises, water seeps from the sand to the surface of the outer pot. It evaporates and in doing so cools the contents of the inner pot. 1. Sweet peppers and tomatoes (which contain essential vitamins when fresh) keep for weeks instead of days. Aubergines, which used to keep for three days, now keep for one month. Spinach, which would wilt immediately in the dry heat, now keeps for up to twelve days.
Benefits to a Nation
Abba made over ten thousand of these systems in the 1990s and distributed them to families throughout Nigeria. Now they can keep their food and eat it when they want to, and the girls can go to school. And Professor Abba is now the proud recipient of a well-earned Rolex Award for Technology. Let's hope he keeps on having good ideas.