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.