Innovative Stoves to Help the Poor
Half of the world’s population cook with a fuel-burning stove, and this figure rises to 80 per cent of households in rural areas in developing countries. Typical fuels burned include wood, coal, crop leftovers and animal dung. The indoor pollution from smoke and carbon monoxide is a top health hazard in the developing world, ranking just behind dirty water, poor sanitation and malnutrition. The World Health Organization (WHO) estimates that 1.6 million people die each year as a result of toxic indoor air.
A landmark five-year study comparing Guatemalans cooking on open fires, to those using improved stoves, has brought more evidence forward of the damage done by indoor air pollution: “It’s been shown that children living in houses using open fires with solid fuels will have more pneumonia than children living in houses that are using cleaner fuels,” said Dr. Kirk R. Smith, an environmental health scientist at the University of California, Berkeley.
The research, combined with studies in Asia, suggests additional health problems from indoor air pollution, including higher frequency of cataracts, partial blindness, tuberculosis, low birth weights and high blood pressure. The researchers found that cleaner stoves had larger effects than reducing salt in the diet on lowering blood pressure in women, with the results published last July in Environmental Health Perspectives.
But Southern innovators are finding practical ways to curb pollution from indoor cooking and the burning of trash in slums.
In Yunnan Province, China, entrepreneur Hao Zheng Yi’s Yunnan Zhenghong Environmental Protection Co. has been selling clean-burning stoves to rural farmers. One fifth of rural China has no electricity (UN), and 80 per cent rural dwellers burn wood or straw in ovens for heating and cooking. This creates heavy indoor air pollution, damaging health.
The so-called Efficient Gasification Burning system combines traditional fuel and natural gas: a hybrid that helps low-income households to affordably use the stove and not pollute their indoor air.
The stoves are sold for a profit in Yunnan Province, and so far 50,000 have been sold. Because the ovens are sold for a profit, Zhenghong had to consult extensively with the farmers in the design phase to make sure the ovens meet their needs.
The result has been that Zhenghong ovens run for five to eight years using the same amount of wood and hay a conventional oven burns in one year.
Another source of air pollution is burning trash in slums. The lack of formal trash removal services in slums has two bad consequences: one is the pollution and poison from rotting rubbish leaching into the soil and water table; the other is ad-hoc burning of the trash to get rid of it, which pollutes the air with a toxic, acrid stench. In Nairobi’s Kibera slum - the second biggest in Africa - over 60 per cent of the city’s residents live in the slum, and are bypassed by garbage collection services. Garbage is piled up along the muddy roads and paths, or hangs in the trees.
The Kenyan NGO Umande Trust, which specialises in water and sanitation projects, has developed a home-grown method to burn trash and avoid having to turn to very expensive and complicated incinerators from Europe. The sheer quantity of trash that needs to be burned in the slum means smaller solutions will not be able to handle the problem.
Its “community cooker” re-uses garbage from the community as fuel for a boiler and oven attached to it. The heat generated by burning the rubbish provides hot water and cooking facilities - and also jobs for unemployed youths who collect the rubbish and stock the incinerator. It was developed by a Kenyan architect, and it is hoped the “community cooker” will be taken up across Africa.
The community cooker’s inventor, Kenyan architect Jim Archer, took eight years to design and build it: “My thinking was how do we get rid of the rubbish and …how can we induce people to pick it up. Then I thought, well if we can convert it to heat on which people can cook…” he told Australia’s ABC News.
Similar industrial scale trash incinerators can cost between US $50 million to US $280 million (World Bank) - “…when applying waste incineration, the economic risk of project failure is high…”. The community cooker on the other hand, will sell for US $10,000.
The idea was to create an incinerator that was simple to use and repair: something that the commercially available, computer-controlled incinerators were not able to do. As the cooker gets up to speed, it will be able to burn 60 per cent of the slum’s trash.
Local youth go house-to-house collecting trash. They get money from the slum residents for this. Rubbish is then exchanged for cooking time or hot water for washing.
"The trash has started to help us a bit after the cooker came. There are fewer diseases like diarrhea and the environment has improved. ... I think burning the rubbish will bring good health to this community," said Patricia Ndunge, as she fried onions on the cooker.
And it looks like the community cooker has a future: Kenya’s largest supermarket, Nakumatt, has pledged to pay for 20 more slum cookers.
- Envirofit: A Shell Foundation supported project to produce 300,000 clean, wood-burning stoves for the developing world (starting with India, Brazil, Kenya and Uganda). Envirofit will offer a variety of sleek ceramic stoves from single to multipot, with and without chimneys, and with colors like apple red, baby blue and gold. The cost is to start at $10 to $20 and run to $150 to $200.