introducing solar ovens to rural kenya

you can see photos from this project here.

princeton, n.j.--for the past three years, daniel kammen, princeton university assistant professor of public and international affairs, has been involved in a project to introduce solar ovens to rural kenyan communities.

"more than two billion people worldwide depend primarily on wood for their energy needs," kammen says. "biomass burning leads to deforestation and contributes up to 40 percent of global greenhouse gas emissions. it's also firmly linked to acute respiratory infection, which is the leading health hazard to women and children in developing countries." domestic cooking accounts for 60 percent of wood-burning in developing nations and as much as 90 percent in some areas, kammen says, but simple, cheap technology is available to reduce wood-burning for that purpose by half -- or more.

"the solar oven," he says, "is remarkably simple, just an insulated box with a glass top. it works by the green-house effect: light enters through the glass and is absorbed and reflected by the foil-covered walls as infrared radiation (in other words, heat); the glass blocks the infrared, so the heat stays in the box, where it cooks food like a crock pot -- slowly but steadily, as long as the sun shines."

in kenya the sun shines enough to make the solar oven a viable adjunct to the traditional way of cooking over open fires or on little cookstoves fueled with wood. "people don't like to abandon the way they're used to doing things," kammen says, "but they'll adopt new ideas if they see the use of them."

winning people over to the concept

kammen's project is structured to win people over to the concept of the solar oven rather than simply to provide ovens.

"first we take a solar oven into a community, make up a stew or cake and put it in the oven. then we sit back and talk for a while. we tell people how it works and talk about how to build it. then we come back to the oven and show off the cooked food proving it really works."

a stew made with rice, meat, potatoes and tomatoes takes about three hours to cook in a solar oven on a sunny day. a pot of water takes about half an hour to boil for tea. "people can cook the foods they're used to, in the pots they already have," kammen observes. "it just takes longer than over a fire." for members of the microwave society, that may seem like a serious drawback. but or members of rural kenyan communities, where gathering firewood is the most time-consuming task of the day and respiratory infection from smoke inhalation is the most frequent cause of death in children, the extra effort of advance planning may not seem excessive, particularly for people who work in markets or fields near their homes.

"after they've seen our demonstration," kammen continues, "we encourage the community to form a committee and discuss whether they want to pursue the project. if they do, we come in with materials and conduct a workshop for three or four days in which we help community members build the ovens themselves. the materials are simple and affordable -- plywood, foil, glass, nails -- but there's quite a lot of carpentry work. it takes a while to make each oven, and once people have done it themselves, they're invested in it. they use the ovens. and when they do, other people get interested."

an integral part of kammen's approach is training community members to teach others how to make and use the ovens. he and his collaborators help establish local "renewable energy committees" that can continue to organize and conduct workshops when the foreigners have gone home. "it's technology transfer and project management transfer," he says.

"the principle of the solar oven has been known for a long time," kammen points out. "a basic design was published in 1884 in scientific american. the version we use is similar to the model invented in the 1950s by maria telkes, who used to work at princeton research labs. it was introduced in a number of developing countries in the '60s and '70s, with minimal success. i think what was missing in those projects was the social component. now we work very hard on education and community involvement. local health and environmental issues are the biggest motivation for adopting this new behavior, and local management is the best way to keep it going."

support for the solar oven project is provided by earthwatch, a u.s.-based environmental-action organization, and several kenyan institutions: the university of nairobi, the kenyan national academy of sciences, the ambassadors development agency (of east kenya) and the african center for technology studies (acts), which now has a staff member devoted to the program: project manager monique nditu, a graduate of the university of nairobi, and community leaders christine mwende and josephine mwota, all of whom trained with kammen.

during the summers of 1992 and 1993, kammen, half a dozen volunteers, three students from developing countries and several kenyan teachers visited between 20 and 30 communities and conducted full-scale projects in six. "the largest," he notes, "was zombe, a market town of about 800 families. we helped build 60 ovens there, and now the community continues building and selling ovens on its own."

in all, he says, the project has helped introduce approximately 110 solar ovens in east kenya, and there is a waiting list of more than 60 communities that have requested informational visits. nditu and others in kenya are working on that waiting list now; kammen will go back with his earthwatch volunteers to continue in june. "i can only do three or four workshops a season," he notes, "so you see how important it is to have a network in kenya that can work year-round."

physics phd

for his part in the solar oven project, kammen recently won japan's 1993 21st century earth award. this carries a cash prize of $45,000, which he is using to subsidize efforts connected with the project both in kenya and at princeton. in addition, he recently received a grant from the u.s. department of energy to study the introduction and dissemination of renewable energy technology in africa.

at the university since september 1993, kammen is serving this year as head of the woodrow wilson school's program in science, technology and public policy. he brings to the faculty an eclectic background, including both a bachelor's degree and phd in physics. "i started college in asian studies (my friends used to say i majored in marx) and physics," he recalls. "for my phd i studied neural networks, modeling the brain; it was really an intersection of physics and biology."

paralleling kammen's interest in science was an interest in developing countries. during graduate school he worked on development projects in latin america and southeast asia. he "got involved with solar oven work" in managua with william lankford of george mason university, which he continued while doing post-doctoral research at california institute of technology. he established the project in africa while working as a research associate at harvard's northeast regional center for global environmental change and in the physics department.

kammen's interest in environmental and development issues extends beyond kenya and solar ovens. "the oven project is just one component of what i call the renewable energy project," he observes. "others include improved stoves for traditional openfire cooking, manure-fueled underground plants that produce methane for home heating and cooking, and small windmills for

pumping water. there are many new technologies that could improve both the environment and the lives of people in many different societies and climates." kammen believes that the community oriented process of implementation is crucial to the success of these new technologies in developing countries. and he plans to keep on proving it.