is Mohammed Bah Abba's Pot-in-pot invention. In northern Nigeria, where
Mohammed is from, over 90% of the villages have no electricity. His
invention, which he won a Rolex Award for (and $100,000), is a
refrigerator than runs without electricity.
Here's how it
works. You take a smaller pot and put it inside a larger pot. Fill the
space in between them with wet sand, and cover the top with a wet
cloth. When the water evaporates, it pulls the heat out with it, making
the inside cold. It's a natural, cheap, easy-to-make refrigerator.
instead of perishable foods rotting after only three days, they can
last up to three weeks. Obviously, this has the potential to change
their lives. And it already has -- there are more girls attending
school, for example, as their families no longer need them to sell food
in the market.