At UC Davis, the food scraps left behind on the plates of students, staff, and faculty,
who eat in the campus dining commons, won't be heading to the dump when it's thrown away.
It'll help power the university after being treated at the renewable energy anaerobic
digester, or biodigester, which was developed by UC Davis professor Ruihong Zhang, and built by
Sacramento-based partner Clean World.
Well, in the biodigester we use bacteria to break down and digest food and other waste
into biogas. Biogas contains methane, mostly, and can be used for energy generation. This
technology is a game-changer, so it has changed the way we manage our solid waste. It will
allow us to be more economically and environmentally sustainable.
The biogas created in the digester is burned off by state-of-the-art microturbines, which
generate electricity that is fed right into the campus grid. Heat generated from that
process is also captured and turned into energy.
This system was designed to handle up to 50 tons per day, every day, seven days a week,
365 days a year, of food waste which is typical of the kind of food waste you get from grocery
stores, or even from your home. We've got about 900 kilowatts of generating capacity
here. We're actually taking landfill gas from the landfill, combining it with the gas that
we're getting from the digester, and generating about 800 kilowatts of electricity. That's
enough to power about 800 homes.
So half of the waste is going to be coming from campus sources: the dining commons, the
animal facilities such as the dairy and the hog farm, as well as crop residue from the
experimental gardens and experimental crops that are around campus, and the brewery and
the winery. The other half of the waste is coming from the community. From local retailers
that have distribution facilities nearby, as well as from other businesses in the community.
The benefits of this project will carry far beyond the campus. Waste from the Sacramento
region, normally destined for the landfill, will be turned into clean, renewable energy.
I think it's incredible. Because it's going to help us reduce our use of brown energy
and reduce our carbon footprint. It also is like a seed we've planted, and already people
are looking for more opportunities on campus to capture more of our organic waste streams
and to take them out there. So it's really just the beginning I think of what will happen
over time.