Princeton University’s new biodigester makes food scraps sustainable
Princeton University’s latest sustainable innovation can be found along the edge of campus just behind FitzRandolph Observatory. There, under a white tent, hums a new biodigester that turns food waste into nutrient-rich compost. Since operations began in fall 2018, more than 16 tons of food scraps have been converted into compost.
A ribbon-cutting ceremony on Tuesday, Jan. 8, officially celebrated the launch of the Biodigester Demonstration Project. Approximately 50 staff, faculty, students and local officials, including Princeton Mayor Liz Lempert and Council President Jenny Crumiller, gathered to mark the University’s ongoing sustainability achievements.
“The Office of Sustainability is unwavering in its dedication to introduce important new technology to our campus,” Vice President for Facilities KyuJung Whang said. “Through the help of so many people here today, we were able to do what we do best, which is to identify a challenge, research smart solutions and work together to create change.”
Through a partnership between Facilities and Campus Dining, the aerobic in-vessel composting system (known on campus as "the biodigester") converts food waste from Frist Campus Center and other campus cafes into compost. The team plans to collect scraps from more campus locations and events this year. Come spring, the compost will be tested as a natural soil improvement on University lawns.
“Waste in global food and agriculture systems is a significant global issue,” Director of Sustainability Shana Weber said. She cited research from the Food and Agriculture Organization of the United Nations on how food in landfills contributes to greenhouse gas emissions and in turn exacerbates climate change. “This project helps us tinker with how to reduce greenhouse gas emissions and how to revitalize soils, reduce fossil fuel uses, and spark innovations in zero waste systems.”
Whang said it took “innovative thinking and problem-solving” across several departments and community partners to install and operate the biodigester. He added that the University’s commitment to sustainable waste reduction aligns with the town of Princeton’s sustainable initiatives, such as its curbside organic waste collection.
“[The biodigester] shows the value of working at a tangible, local level to combat major sustainability challenges,” Whang said.
The project also is an example of Princeton’s campus-as-lab approach, providing research and teaching opportunities for faculty and students. Weber had her own class, “Investigating an Ethos of Sustainability at Princeton,” tour the biodigester last fall, and 14 undergraduates are operational assistants at the facility.
“It’s really important that Princeton has a whole machine dedicated to sustainability,” said sophomore Wesley Wiggins. “Working here has made me want to spread the word [to other students] about how they can contribute. It also makes me think differently about what I eat in the dining halls and how I can limit my own food waste.”
Sustainability Project Assistant Gina Talt, who oversees day-to-day operations at the biodigester, said the project underscores Princeton’s larger commitment to sustainability. She hopes the project will inform how the University and other institutions can successfully compost on-site.
“As someone who was involved in environmental initiatives through my undergraduate years at Princeton, I greatly appreciate the opportunity to literally get my hands dirty and engage in real-world sustainability problem-solving with tangible impacts for the campus and beyond,” said Talt, a member of the Class of 2015. “I’ve developed a deep appreciation for all that goes on behind the scenes at the University, sometimes unnoticed, and all the partnerships, efforts and leadership that goes into planning, implementing and enacting change.”