Over two billion people still use wood in open fires for their cooking. Kim has written that it is "leading to rampant deforestation, respiratory disease (like asthma, pneumonia, lung cancer, bronchitis) and worsening poverty."- it takes as much as 30 hours a week in time and 35% of income. Equivalent to smoking 40 cigarettes per day, it kills 1.6 million people per year.
TreeHugger has written about many different stoves designed to address this problem, but the PlanetStove from Novotera has an interesting twist: Instead of burning the wood and ending up with ash, it restricts the airflow and heats the wood with very little oxygen, making biochar, which can be mixed with soil. They explain:
A natural soil enhancer, biochar significantly boosts plant growth and root development when used properly, improves soil water retention and permeability, reduces soil acidity, helps to retains nitrogen and phosphorus in the soil, and encourages beneficial micro-organisms. Recent biochar soil-treatment trials have shown a doubling and sometimes even a tripling of crop yields. And of course, when you mix biochar in your soil, you're sequestering carbon and thus really doing something about climate change.
Instead of a waste product, this creates an opportunity, because the biochar has real value.
A Planetstove can produce one Kilo of charcoal for each three Kilos of wood fuel, both of which sell for three RMB in parts of China. The stove thus produces a valuable product that can be used by the owner for further cooking, for sale, or for soil improvement. Wood that a villager would have burnt anyway for cooking can thus provide further benefit without extra cost, other than the stove.
The designers of the stove are trying to raise funds on Indiegogo to subsidize the sale price of the stove; it costs $35 to make in China but they have determined that the rural Chinese farmers that that are the market cannot pay that much. They have a ways to go to reach their target.
Designing a stove is just a small part of the problem; lots of people have thought they had a world-changing version. The problem is often the distribution and support. The people at Novotera appear to have thought that one out:
We employ a range of distributors, including village leaders. Such people are well situated to distribute due to their position of respect within the community, and their connections with other nearby communities. Cookstove dealers as well as pot and pan sellers are another important type of distributor, as are restaurant owners. Sometimes local farmers also see the business opportunity although they often need more credit support.
It's not just a stove, it's a business plan. More at Indiegogo.