Here’s how Sacramento State turns wasted food into clean energy
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- Sacramento State converts food waste into renewable energy via anaerobic digestion.
- The university won a national zero-waste competition through composting and reuse.
- Campus sustainability efforts rely on student engagement and behavior change adoption.
Sacramento State’s sustainability team has found a powerful use for campus food waste: converting it into electricity. The energy is enough to power a small dining hall kitchen, but for now, it’s used to keep dining hall macaroni and cheese warm.
The team transfers waste collected from the catering kitchen and brands on campus to an anaerobic digestion system that converts the waste into natural gas, according to Laura Gonzalez-Ospina, waste and sustainability analyst in the Office of Sustainability. That natural gas is converted into electricity stored in a power bank battery used to heat food at later events.
“It’s actually funny because we proved that (the energy generated by food waste) is enough to run one of the small kitchens on campus,” Gonzalez-Ospina said. “But, at the moment, we use it to keep events running on clean energy instead of using generators.”
The team is run through the school’s Office of Sustainability and dedicated to managing wider waste, energy and greenhouse gas emissions for the campus.
In July, Sacramento State’s sustainability team won the National Wildlife Federation’s Campus Race to Zero Waste competition in the Food Organics category in a nationwide waste reduction and recycling competition. The team competed against more than 80 other colleges and universities from the United States and Canada over an eight-week period, turning food scraps into renewable energy and compost. Edible food was redistributed to the campus community through the Epicure Extras program, providing students access to meals or snacks that would be discarded from events.
Last year, the team received a grant for an in-vessel composter that they used to devour the competition, Gonzalez-Ospina explained. The machine collects food from Dining Commons, the largest cafeteria on campus that serves about 6,000 meals a day during the school year, and donates finished compost to nearby schools starting community gardens.
“This was the first time that the campus participated in the race, and it was something we kept in our Office goals for a long time but didn’t have the bandwidth to do,” Gonzalez-Ospina explained. “I thought, honestly, we were going to be really bad, but to my surprise, we actually did really well.”
The office collected data every week from February to March from their food waste conversions and sought student support to inform the campus community of the team’s efforts.
Joshua Maddox, an energy and sustainability analyst in the office, has named the efforts “Waste to Watts.”
“It takes energy and resources to distribute and purchase products,” Maddox said. “So if we develop a system’s level thinking of how we can reduce our waste, we’re also inherently reducing energy that it takes to run our society and live our lives.”
The office offers programming for Sac State students to get involved with gardening, forestry and composting. Produce grown through the student garden is donated to a campus food pantry to ensure students have access to organic fruits and vegetables.
Gonzalez-Ospina and Maddox are most proud of the Hornet Surplus Program, which provides reusable goods and furniture to campus departments, saving the university money and preventing waste.
The Office of Sustainability is also in the process of launching a similar program called Hornet Reuse — a platform, comparable to Facebook Marketplace, that allows students to request and receive free school supplies from their peers.
“It’s a great way of keeping things out of the landfill, providing resources for students, and hopefully saving them money,” Maddox said. “It also builds a culture around not throwing things away and thinking of things as waste instead of interesting ways to get connected on campus.”
By 2030, the university hopes to be a zero-waste campus, according to a sustainability report from four years ago. This past school year, the office of Sustainability composted more than 930,000 pounds of food and recycled more than 620,000 pounds of waste. The school serves more than 31,000 students, according to the university’s fact book.
Gonzalez-Ospina said that the Campus Race to Zero Waste win was symbolic of the work and indicative of a growing campus involvement in food systems and waste reduction.
“We have some that are not so open to it, but I believe more and more new students want to experience firsthand how to compose and how to get jobs and internships in sustainability,” Gonzalez-Ospina said.
She noted that the biggest roadblock to the university’s zero-waste goal is convincing students and faculty to engage in behavioral changes.
Gonzalez-Ospina has often observed people, especially older individuals, chuck plastic and paper into a nearby waste bin instead of a proper recycling bin.
If someone has put their waste in the trash consistently for the last 30 years, it’s going to take them some time to consider separating them into different bins, Gonzalez-Ospina said.
“As a society, we don’t want to think about our waste,” Gonzalez-Ospina said. “We don’t want to smell it; we just want to throw it away as fast as we can. But to achieve zero waste, we need to take a few seconds, read the signs, put waste in the right place and make it a habit.”
