A NIGERIAN teacher has invented a remarkably simple and cheap cooler for
storing fruit and other perishable foods. Mohammed Bah Abba鈥檚 award-winning
鈥減ot-in-pot鈥� system needs no external energy source and is already improving
life in semi-arid northern Nigeria.
One earthenware pot sits inside the other, with wet sand filling the space
between them. You put food in the smaller pot, and cover it with a damp cloth.
Warm air outside draws moisture to the surface of the outer pot, where it
evaporates. The water vapour carries heat away with it, so this drying action
creates a constant heat flow from the interior of the pot, as long as the sand
and cloth are kept wet. This effect keeps the contents of the inner pot cooler
than the outside air.
Northern Nigeria is a very poor region. Its rural communities eke out a
living from subsistence farming, and with no electricity鈥攁nd no
refrigeration鈥攆ood normally spoils in days. According to Abba, trials of
the system have been extremely successful. Aubergines, for example, stay fresh
for 27 days instead of three, while tomatoes and peppers last for more than
three weeks.
Advertisement
The pot-in-pot system is already up and running in several villages in Abba鈥檚
home state of Jigawa. 鈥淔armers are now able to sell on demand rather than `rush
sell鈥� because of spoilage,鈥� he says, and the system means girls no longer have
to sell food every day. 鈥淚nstead, they are free to attend school, and the number
of girls enrolling in primary education is rising in the villages where it is in
use,鈥� he adds.
Abba this week became one of five people to win a Rolex Award for Enterprise
for his low-technology innovation. He intends to use the $75,000 prize
money to make his invention available throughout northern Nigeria and,
eventually, beyond.
