More than half the world's population cooks using biofuels: wood, charcoal, dung or crop waste. The women who use cookstoves spend hours a day searching for wood, or in urban areas, spending money on charcoal. In both cases, the wood consumed contributes to deforestation. The stoves produce a great deal of smoke, leading to respiratory disease, especially in children.
As Alex observed in an early WorldChanging post, building a better cookstove is a task that has multiple impacts: it reduces costs for stove users, improves the health of the women who cook with the stoves and benefits the environment by using renewable resources more efficiently. And cookstoves have been one of the major projects the "appropriate technology" movement has targeted over the past thirty years. But it's harder than it looks - not only does a stove need to be efficient, it needs to be easy to manufacture, repair and use, and needs to be worth the substantial investment women make in purchasing it.
Richard Njagu, a Kenyan inventor and entrepreneur, is well aware of the challenges of creating technology for the developing world. Trained as a "Jua Kali" mechanic - a handyman who works in the informal sector - Njagu started his career repairing gasoline and diesel engines before designing machines to build soil blocks, which he used to construct inexpensive houses and water tanks.
In 1995, Njagu turned his attention to the problem of cookstoves. Working with a Peace Corps volunteer, Todd Harris who had trained with Aprovecho, an appropriate technology lab based in western Oregon. Harris introduced Njagu to the "Rocket Stove" invented by Dr. Larry Winiarski. Njagu combined this design with aspects of the Jiko stove, which had been brought to Kenya in the 1980s by aid groups like UNICEF and CARE.
The result is an attractive, efficient and inexpensive stove that Njagu calls the Henya Stove. Like the Rocket Stoves, it uses an elbow shape - fuel is fed in from the side, and exhaust gases are captured to help produce heat. The stove liner is made from local clay, like the Jiko stoves, and contributes to the stove's efficiency by preventing heat from leaking out from the sides.
Njagu is looking for help marketing the stove and scaling up production. He's had some help from ApproTec, a Kenyan-based NGO best known for their MoneyMaker foot operated irrigation pumps, but he'll need more help to get people using the Henya stove both in and beyond Kenya.
(Thanks to Emeka Okafor at Timbuktu Chronicles for his post alerting us to the Henya stove.)