A biogas digester sounds like a complicated piece of scientific equipment, doesn’t it? After all, if it takes care of your leftover food while creating renewable energy for your home at the same time, it has to be rather complex, right?
Not exactly.
As you can see, the one built by Thomas H. Culhane isn’t. It’s just a small bucket sitting inside a larger one and a few plastic tubes.
And it’s precisely this simplicity that makes it so beautiful.
In the video below, Culhane (an urban planning professor and a member of the National Geographic Emerging Explorer program) demonstrates that with just a few supplies from a hardware store, you can construct your own biogas generator.
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“Once you understand the principle you can build a home system that uses all your kitchen garbage and gives you up to 2 hours of gas every day,” he says.
Here’s how it works: When the biodigester is fed organic waste, the bacteria inside the larger bucket eats it up and converts it into methane gas through a process called anaerobic digestion. The gas that’s created can then be used to generate heat for cooking, water, or electricity, while the digested leftover waste can be used as a high-quality fertilizer.
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Culhane has taken his invention around the world, from the slums of Cairo and the favellas in Brazil. As the Christian Science Monitor reports, he founded Solar CITIES Solutions, an NGO (non-governmental organization) that provides materials and training for individuals in impoverished communities to create sources of clean, renewable energy in their homes.
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While Culhane’s approach is meant for the average home, biogas is being championed for large-scale as an alternative to fossil fuels. The Natural Resources Defense Council says that the use of animal manure biogas is the “ultimate win-win energy source,” as it allows farmers to make their own energy, reduce water contamination, odor pollution, and global warming emissions caused by animal waste.
Turning waste into a resource. Now that’s an idea that shouldn’t go to, ahem, waste.
Tag: biogas
See How This University Is Turning Trash Into Treasured Clean Energy
Within the dining halls at the University of California, Davis, tossed-out food scraps have recently become empowered—quite literally.
Waste is being converted to power in the campus’s newly unveiled Renewable Energy Anaerobic Digester (“biodigester” for short), a set of large, white tanks that eat 50 tons of trash per day and burp out 12,000 kilowatt hours of renewable electricity, right into the campus’s grid. That’s enough to power almost 1,000 homes for a year, says a UC Davis release.
The mound of trash feeding the biodigester is composed of not just UC Davis cafeteria food scraps, but also campus yard clippings and waste from local restaurants and businesses. The system is expected divert 20,000 tons of waste from local landfills each year.
Unveiled on Earth Day, it’s the U.S.’s largest anaerobic biodigester on a college campus, and it owes its existence to technology developed by UC Davis biological and agricultural engineering professor Ruihong Zhang. Anaerobic digestion isn’t exactly a new concept, but the UC Davis biodigester, built using Zhang’s technology, can consume more waste—and a greater variety of it—than previous versions, significantly increasing its efficiency.
Zhang had been working to get her patented technology out of the lab and onto the campus grid for nearly a decade, but found funding to be a major obstacle. When the university partnered with Sacramento-based CleanWorld—a tech company focused on anaerobic digestion systems—the UC Davis biodigester finally had the means to reach commercial scale. CleanWorld paid for the majority of the $8.5 million biodigester with private equity and commercial loans—though $2 million in public assistance came from the U.S. Department of Energy and the California Energy Commission.
Here’s hoping that other U.S. universities take note, and find ways to get their food scraps—and campuses—similarly empowered.
Robot Bacteria Are Coming for Your Sewage
Unbelievable as it sounds, mutant robot bacteria is coming to eat up our cities’ waste water. This emerging technology, piloted by Pilus Energy, is designed to make electricity, clean water and other fuels. If it works out, it could reduce municipal waste, recover water and make clean energy. There’s a home model in the works too.
We always knew home robots were going to be a reality eventually, but who knew they’d be no bigger than bacteria?