Pop Cans, Rice Husks, and Global Learning
By Jean Florman
Question: What do aluminum cans, sand, and rice husk have to do with educating University of Iowa engineering students?
Answer: The students are learning how solar-powered ovens--including one design that uses pop cans, sand, and rice husks--may serve to help prevent deforestation in India, improve the well-being of village women and girls, and jumpstart a "new industry" to enhance the local economy.
Last January, University of Iowa students were part of a team that traveled to India during the three-week University of Iowa course, “Energy for Sustainability at the Forest’s Edge: How to Balance Rural Life with Wildlife Preservation.” Taught by Professor of Mechanical and Industrial Engineering H.S. Udaykumar, the “winterim” course provided an opportunity for students to explore how alternative, renewable energy systems can decrease the exclusive reliance on wood fuel and begin to change the longstanding pattern of severe deforestation that has profoundly damaged the economic, social, and physical wellbeing of the residents of two Indian villages. “Two billion people on earth cut forest wood for fuel every day,” Udaykumar says, “so providing effective, inexpensive, renewable fuel sources for cooking will address a critical human need and help slow the massive deforestation taking place around the world.”
In India alone, the landscape has shifted dramatically from thirty per cent forest to less than seven per cent in just 50 years. And as the forests recede, villagers—mostly women and young girls—must venture farther and farther and spend more time gathering fuel every day. The social, economic, health, and environmental costs are enormous and growing.
Before visiting the villages, the students studied the design and impact of several different solar cooking devices and began considering the cultural and social impacts of such technologies. They worked with Climatehealers (www.climatehealers.org), based in Berkeley, CA, and India-based FES (fes.org.in), two nonprofit organizations that focus on ways to balance the economic and environmental needs of indigenous people. The Iowa students learned about the delicate balance between the demands of daily living, the desire to improve the quality of life by accessing modern conveniences, and the essential need to preserve the environments that support us.
Based on this background knowledge, the team prepared a series of questions and strategies for an impact study which they carried out in two villages in western India near the Kumbalgarh Wildlife Sanctuary. Once on site, the Iowa team met with the entire village first to explain the project and secure support. The students then spent two days interviewing members of 30 households—slightly more than 10 percent of the total population—focusing on food preparation needs and patterns of behavior and examining the effectiveness of several simple cooking devices. Because women are responsible for collecting the fuel and cooking—an effort that requires as much as five hours a day in dangerous terrain at considerable distance from the village—the students made certain each UI team included at least one woman interviewer.
In addition to better understanding the daily vicissitudes of securing fuel and cooking in smoke-filled rooms, students also learned why two solar cooker models had previously failed in the villages.
“The designs were large, bulky, and had to be adjusted every fifteen minutes,” says Jaclyn Richards (BSE 2011). “In addition, the cookers were made of glass tubes, which were heavy, fragile, and couldn’t be provided locally.”
Students also learned that technological design and availability are not the only critical constraints to adopting new, seemingly more effective technologies. Engineers and nonprofit organizations that hope to make an effective impact must also listen and observe to learn more about how people interact with technology, the environment, and each other.
“For obvious reasons, solar ovens must be used outdoors,” say Matthew Toth (BSE 2011). “But people in the villages didn’t like the idea that their neighbors could see how little they had to eat, so they didn’t want to move their cooking operations outside.”
One possible solution to that, of course, might be for everyone in the village to have access to solar cookers. The villagers may then come to value the new technology if it helps improve the safety of women and young girls, frees up time for other important pursuits, protects the rapidly dwindling forests, and potentially enhances the local economy through the production and sale of similar solar ovens.
With input from the villagers, Professor Udaykumar, and the staff of the two nonprofits, the students formulated the requirements—technical and otherwise—of a solar cooker that would more successfully meet the needs of the villagers. The design constraints include mobility, protection from weather, storage capacity, use of easily renewable fuel, and a per-unit cost of less than $200, which will be covered by the two nonprofits.
Other UI engineering students are now building on the findings of their 2011 winterim colleagues to develop and test a solar cooker that meets the parameters established during the India trip. The new design—appropriately named the “Hawkeye Cooker”—collects the sun’s energy with a lightweight aluminum parabolic trough reflector. The heat is transferred into a box filled with sand and aluminum pop cans, which are surrounded by another box filled with insulation provided by rice husks, available by the gigaton in India. The cans enhance heat transfer to the cooking surface, and the device can produce consistent heat up to 200°C, hot enough to cook the villagers’ traditional meal of rotis (traditional bread) and vegetables.
“The whole trip was a game-changer for me,” says Ethan Guio (BSE 2011). “I’ve always been interested in the environmental side of engineering, and now I better appreciate the impact of people’s day-to-day constraints and choices. Plus, having seen the global impact of food production, I’m attempting to become a vegetarian.”
“I realized I can make a difference—that I can help empower others through my engineering knowledge and skills,” Brianne O’Loughlin (BSE 2011) says.
“And we all learned that there’s more out there waiting to be done,” Eric Osgood (BSE 2011) adds. “Achieving real-world impact is something worth working for.”
The new design—appropriately named the “hawkeye cooker”—collects the sun’s energy with a lightweight aluminum parabolic trough reflector. The heat is transferred into a box filled with sand and aluminum pop cans, which are surrounded by another box filled with insulation provided by rice husks, available by the gigaton in india.the cans enhance heat transfer to the cooking surface, and the device can produce consistent heat up to 200°c, hot enough to cook the villagers’ traditional meal of rotis (traditional bread) and vegetables.