In China, India, and sub-Saharan Africa, people in 80 to 90 percent of households cook food using wood, animal manure, and crop residues as their fuel. Since women do most of the cooking, and young children are with the women of the household for much of the time, it is the women and young children who receive the greatest exposure to carbon monoxide and particulate matter. When biomass is used for cooking, concentrations of particulate matter in the home can be 200 times higher than the exposure limits recommended by the EPA. A wide range of diseases has been associated with exposure to smoke from cooking. Earlier in this chapter, we described that indoor air pollution is responsible for 4 million deaths annually around the world, and indoor cooking is a major source of indoor air pollution.

There are hundreds of projects underway around the world to enable women to use more efficient cooking stoves, ventilate cooking areas, cook outside whenever possible, and change customs and practices that will reduce their exposure to indoor air pollution. The use of an efficient cook stove will have the added benefit of consuming less fuel. This improves air quality and reduces the amount of fuel needed, which has environmental benefits and also reduces the amount of time that a woman must spend searching for fuel.

Increasing the efficiency of the combustion process requires the proper mix of fuel and oxygen. One effective method of ensuring a cleaner burn is the use of a small fan to facilitate greater oxygen delivery. However, because most homes in developing countries with significant indoor air pollution problems do not have access to electricity, some sort of internal source of energy for the fan is needed.

Two innovators from the United States developed a cook stove for backpackers and other outdoor enthusiasts who needed to cook a hot meal with little impact on the environment. They described their stove as needing no gasoline and no batteries, both desirable features for people carrying all their belongings on their backs. They soon realized that their stove, which could burn wood, animal manure, or crop residue, could make an important contribution in the developing world. This stove, called BioLite, physically separates the solid fuel from the gases that form when the fuel is burned and allows the stove to burn the gases. In addition, a small electric fan, located inside the stove, harnesses energy from the heat of the fire and moves air through the stove at a rate that ensures complete combustion. The result is a more efficient burn, less fuel use, and less release of carbon monoxide and particulate matter. The stove weighs 0.7 kg (1.6 pounds).

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How did the innovators manage to generate the electricity? They added a small semiconductor that generates electricity from the heat of the stove. All components of the stove except the semiconductor could be manufactured or repaired in a developing country. The BioLite stove won an international competition in early 2009 for the lowest emission stove. It was also the only stove in the competition that required no additional electricity inputs to operate. The BioLite stove is commercially available. One review of it stated that “it charges your phone while cooking your dinner.”

There are many possible hurdles for those who are trying to introduce cleaner, more efficient cooking apparatus to the developing world. Manufacturing costs might make the stove difficult to afford for many. There has been some concern about possible reluctance to accept a different kind of cooking appliance. However, a number of studies in the developing world suggest that most households are quite receptive to using efficient stoves because of the benefits of improved air quality and reduced time spent obtaining fuel. Other promising ways to reduce fuel use and improve indoor air quality include the solar cooker shown in FIGURE 39.2 on page 451.

Critical Thinking Questions

References

Bilger, B. 2009. Annals of Invention, Hearth Surgery, The New Yorker, December 21, p. 84; http://www.newyorker.com/reporting/2009/12/21/091221fa_fact_bilger#ixzz 0sMCn DR00.

www.biolitestove.com, homepage of BioLite stove.