Thomas H. Culhane teaches people to build fuel sources – powered by garbage
Homemade biodigesters turn human and food waste into biogas, which can be used to heat water, cook food, or produce electricity.
It looks like street magic: A food grinder, some lengths of PVC pipe, a couple of 10-gallon buckets, and flexible plastic tubing lie on the table in front of Thomas H. Culhane. He enthusiastically promises the crowd gathered at a biodigester workshop that anyone can use these items to make enough clean-burning biogas to cook food every day using the scraps from yesterday’s meals.
But his magic is backed by hard science.
Dr. Culhane, a member of the National Geographic Emerging Explorer program and a visiting professor at Mercy College in Dobbs Ferry, N.Y., has spent the past five years extolling the merits of locally sourced biogas technology. Based in Germany, with one job in the United States and the shoots of others in the Middle East, he lives the life of a global nomad. His work has carried him to every continent except Antarctica.
Three days earlier he had been in Brazil overseeing the installation of three biogas digesters in the favelas, or slums. But on this spring day he’s in Elsah, Ill., for a conference on sustainability. He’s being honored with a Visionary of the Year award from the Euphrates Institute, a nongovernmental organization headquartered on the Principia College campus located on bluffs overlooking the Mississippi River near St. Louis.
“He really embraces the idea that there are no boundaries, that there are no categories ... and that we really are one human family,” says Rebecca Tobias, vice president of the institute, who presented Culhane with the award.
His compassion and passion for the world may have something to do with his upbringing. Born to an Iraqi mother and an Irish father, Culhane was raised in Chicago but visited Europe and the Middle East a number of times while growing up.
His early love of scuba diving led him to an even greater love of jungles and coral reefs, the most biodiverse places on Earth. After graduating from Harvard University with a degree in biological anthropology, he received a master’s degree and doctorate in urban planning from the University of California at Los Angeles.
Although today Culhane is one of the world’s leading pioneers in small-scale biogas development, seven years ago he had never heard of a biodigester. He was living in Cairo, working on his doctoral dissertation and teaching impoverished communities how to make solar water heaters for their houses.
“We’re in ‘hot water’ as a species primarily because we’re trying to heat water,” Culhane explains with a touch of humor. Hot water, he points out, is essential to everyday life, from making steam for electricity at a power plant to enjoying a hot beverage to sterilizing medical equipment.
In many poor communities, individuals resort to burning plastic or kerosene (both of which produce toxic smoke) to heat water or cook food. It’s understandable as a matter of short-term survival, but it’s not good for long-term sustainability.
Hoping to change that, Culhane and his wife, Dr. Sybille Culhane, moved to a Cairo slum to better understand the situation. There he built his own water tank and solar heating system with help from local craftsmen.
“I worked with a local carpenter ... and a local welder. We built a couple of these [solar water-heating systems],” he explains. “Then I got a grant from USAID [US Agency for International Development] to hire people and train them to build 35 more in the Muslim and Christian communities, and bring them together.”
The project was successful, and Culhane established Solar C3ITIES Solutions, an NGO that provides materials and training for individuals in impoverished communities to create sources of clean, renewable energy in their homes.
Unfortunately, he soon discovered that a substantial number of homes in Cairo don’t have direct access to sunlight. So Culhane began to search for other renewable energy sources, keeping in mind his recycling mantra: “There is no garbage.”
He befriended the Zabbaleen or “garbage people” of Cairo, who are mostly Coptic Christians. He was inspired by the way they found uses for things most people considered waste. He eventually was led to a technology that turns organic waste into renewable energy. He traveled to India, where he learned about biogas systems from Dr. Anand Karve, head of the Appropriate Rural Technology Institute in Pune.
For Culhane, it was like stumbling on the holy grail. “When I built my first [biodigester] in January 2009, I was hooked,” he says. “Nothing could stop me then.”
Biodigesters turn human and food waste into biogas, which can be used to heat water, cook food, or produce electricity. They also make “the best nitrogen-rich fertilizer the world [has] ever seen,” Culhane says. “It could make the desert bloom.”
He grows more enthusiastic as he lists the other benefits of biogas. “I didn’t know when I started that it could be used to run electric generators,” he explains, which adds cars, trucks, refrigerators, air conditioners, and lamps to the long list of things biogas can fuel.
As for the digester’s potent fertilizer, he attributes this directly to food grinders.
“Food grinders are the most important biotechnology of the 21st century,” Culhane says. As they break down fibers, they create more surface area for microscopic bacteria and archaea to feed on.
Archaea, single-celled organisms distinct from bacteria, consume food waste and produce methane, which is then captured and used as fuel. Because the system is anaerobic, or oxygen-less, the digester produces little to no odor, meaning it doesn’t attract flies or vermin.
Emerson Electric Co., which owns InSink-Erator brand food grinders, has partnered with Culhane to develop a bicycle-powered food grinder that can be used to grind organic waste in places that don’t have electricity.
Culhane has few helpers beyond his students and interns, but he believes social media will play a key role in spreading the message. His Solar Cities Facebook group has almost 2,000 members who post pictures of successful projects and discuss issues surrounding biogas.
For now, Culhane fights an uphill battle to make his vision a reality. But he’s not without hope. “We’ve all got toilet waste. We’ve all got food waste,” he says. “That can be turned into solutions.”
Culhane oversees almost all of the work himself, training people in each place he visits and later corresponding with them through social media and e-mail. It is an enormous task.
“That kind of heavy lifting is absolutely necessary in the full-court press that it’s going to take to transform our society away from fossil fuels,” says Byron DeLear, chief executive officer of Energy Equity Funding. Mr. DeLear has known Culhane for more than 20 years and says he has always been driven by a desire for a better world.
Back at the biodigester workshop in Elsah, Culhane has provided blueprints and materials to participants, but no other direction. Students and visitors are hesitant to start working with the materials. No one is taking charge.
By not stepping in, Culhane is allowing leaders to rise from the community, instead of having everyone turn to him. “Unless you’ve spent enough time solving all these problems, your instinct is to back off,” he explains.
By providing materials but allowing communities to solve their own problems, Culhane hopes to create a culture of independence.
“I need to make myself redundant,” he says. “This is supposed to be a leaderless movement.”
Slowly, the group coalesces into teams, each with a specific job. After a few hours and some troubleshooting, they’ve built a watertight biodigester. It will take two to three weeks for it to start producing enough gas to light a flame, but for now, Culhane demonstrates its success by pumping in hydrogen gas and lighting it.
The students and Culhane head off to another meeting, leaving behind their digester – not just a couple of plastic buckets attached by pipe, but a do-it-yourself symbol of hope for an energy independent future.
• For more, visit http://solarcities.blogspot.com.
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