A Pot in Every Pot
People living in the rural scrublands of northern Nigeria survive by subsistence farming: growing, consuming, and selling fruits and vegetables. The desert heat presents a big problem: perishables last just a few days before spoiling. There’s no refrigeration because there’s no electricity.
For Mohammed Bah Abba, a local United Nations worker, the problem was impossible to ignore. He watched as young girls travel long distances each day to sell the produce—leaving no time for school. He watched as produce was sold cheaply or wasted—resulting in loss to an already paltry income or sold in a partly spoiled state—resulting in health hazards. To Abba, the entire health, welfare, and education of his people was tied to the inability to keep produce fresh.
He set about finding some small way to make life easier. He knew that whatever he came up with would have to cost nearly nothing to construct and maintain, work without electricity, and use readily available materials and existing skills. He remembered the clay pots that had been so central to the lives of northern Nigerians during his childhood. He remembered the basics of traditional claywork that his grandmother had taught him. And he remembered enough of his secondary school science to hit upon an idea: cooling by evaporation. Abba’s idea? Clay pots—or rather, double clay pots.
The solution couldn’t be simpler. Place one clay pot inside another. Fill the gap with wet river sand to keep the pots damp. Cover the inner pot with a wet cloth. As the moisture in the gap evaporates from the outer pot toward the dry outside air, the inner pot cools. The wet sand also insulates the inner pot. The drop in temperature chills the contents and kills potentially harmful microorganisms that flourish only at higher temperatures.
Abba’s pot-in-pot desert cooler keeps contents a dozen degrees cooler than the outside air. Eggplants stay fresh for nearly a month instead of three days. Peppers and tomatoes stay ripe for three weeks. Spinach lasts twelve days instead of one. Abba figured a potter can make five complete desert coolers per day. On his small salary, Abba set up potteries using open fires as kilns, employed local potters, and distributed the first 5,000 pots free of charge. A pot costs less than a dollar to make, and he sold it for ten cents over cost.
Today, farmers and traders use the desert coolers to store their produce at home and sell them fresh at a good price. The invention frees young girls to attend school. Abba’s solution has captured the attention of the world. By 2006, well over 100,000 desert coolers had been sold and distributed all over Nigeria.
Water Is Child’s Play
On a weekend fishing expedition to the east coast of South Africa, advertising executive Trevor Field observed a group of women standing next to a windmill, waiting for the wind to blow. He saw that the concrete reservoir at the bottom of the windmill was cracked, so it would’t hold water. When he passed the windmill two days later, the women were still there waiting. The troubling scene stayed with him.
He discovered how serious the world’s water problem is: Over one billion people do not have access to clean water; water-related illnesses are the single largest cause of disease worldwide; and nearly 6000 people each day die because of it. Moreover, abundant safe water is a little more than a hundred feet below the surface, but the resources don’t exist to extract, store, and purify it.
At the same time, Ronnie Stuiver, a borehole driller in the region, is bothered by another observation. When he rolls his rig into a village, the children gather to watch him work, fascinated. Without swing sets or playgrounds, their energy had no outlet. He designed a small-scale model of something he thinks will delight them: a pump with a merry-go-round fitted on top that can be powered by play. As the children spin the merry-go-round, water is pumped from deep in the ground. He put his prototype on display at an agricultural fair in Johannesburg.
On that same day, Trevor Field attended the fair. He spied Stuiver’s pump and instantly saw it not just as a merry-go-round that pumps water, but as a clever way to help people like the women he saw waiting for the wind. He envisioned a self-contained, self-sustaining water system complete with a high-capacity water tank and four large spaces for billboard advertising and public service messages. The ad revenue pays for maintenance. Children playing powers it.
He licensed the idea from Stuiver and formed PlayPumps International to allow the systems to be donated to communities and schools in rural Africa. Today, over 1000 PlayPumps have been installed in the sub-Sahara, with commitments for 4,000 by 2010.
Lesson: if you want to change the world, you need the ability to see extreme resource constraints as the very source of sustainable innovation.
Matthew E. May is the author of In Pursuit of Elegance: Why the Best Ideas Have Something Missing, and blogs here. You can follow him on Twitter here.
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