Banner image: Diego, Ranjit and Ana working to install the biodigester. (Credit: Sharada Prasad)
“It’s a big plastic stomach that’s outside in the yard, with a pipe that leads into the kitchen.” That’s how Ranjit Deshmukh, an ERG Ph.D. candidate, described the biogas digesters he and eight other Berkeley students installed this winter in five households in the Mayan community of Yaxche in Mexico’s Yucatan peninsula.
The contraptions take livestock waste and digest it anaerobically — bacteria decompose the waste, sans oxygen, and convert it to methane and carbon dioxide. The clean-burning methane is used for cooking, and as an added benefit, the digested waste makes excellent farm fertilizer. “It’s the cleanest, most sustainable energy system,” Deshmukh said.
The project was the brainchild of Deshmukh and his former Humboldt State University classmate Alex Eaton, who builds and installs the kits through the International Renewable Resources Institute-Mexico (IRRI), which Eaton directs. The students — eight ERGies and one from the Department of Environmental Science, Policy & Management — wanted to travel, and to contribute to the communities they’d visit. Through IRRI they identified a community that used three-stone fires, the most polluting kind of cookstove.
The students raised $2,000 from friends and family to cover the cost of five prefabricated digester kits, and a Yucatan nongovernmental organization, Fundacion Mundo Maya, partially matched their funds. Everyone paid their own travel expenses.
Working together with the locals, the group installed the biogas generators. Of course, new stoves meant celebratory cooking. The best post-installation meal? “Definitely the homemade waffle cones and ice cream,” Deshmukh says.
This article originally appeared in Breakthroughs, the magazine of UC Berkeley Rausser College of Natural Resources