Image: Detroit Zoo
By JOSH THALL
Lansing – The Detroit Zoo plans to build a machine to effectively use one of its more plentiful resources – manure.
The zoo’s proposed $1 million anaerobic biodigester would break down animal waste and produce a biogas as a source of electrical energy. It would be the first zoo-based biodigester built in North America.
It could save the zoo around $70,000 to $80,000 in electricity per year, said Gerry VanAcker, the chief operating officer for the Detroit Zoo. Another $30,000 to $40,000 could be saved in operational costs, including cleanup, disposal and equipment expenses for the current waste-disposal process.
“Currently, the waste goes downtown to a composter, then it’s composted, but as you can imagine, that methane is released into the environment,” VanAcker said. “What it actually does is reduce the ozone layer and contributes to our carbon footprint.
“So instead of that methane being released into the environment, it’s used to generate electricity, and that reduces our use of fossil fuels.”
Funding includes an Erb Family Foundation donation of $600,000. The zoo is contributing $100,000 of its own funds and has applied for two $100,000 grants from the Department of Environmental Quality and the Michigan Economic Development Corporation.
The final $110,000 is being raised through a crowdfunding campaign, put together by the Detroit Zoo and the Michigan Economic Development Corporation. If the crowdfunding campaign reaches its goal of $55,000, the Michigan Economic Development Corporation will provide a matching grant
That campaign raised $11,344 as of April, 24, with 52 days left to donate. You can donate here.
VanAcker hopes to raise the money sometime in June, to break ground in July and to have the biodigester operational in the fall.
The zoo has been working very closely with Michigan State University’s Anaerobic Digestion Research and Education Center since the idea was introduced in 2012. MSU has helped provide the zoo with information about the energy potential of their waste and what technology is best suited to convert their animal waste into the renewable energy.
The biodigester will be large enough to digest the 400 to 500 tons of animal waste the zoo creates each year. It will power the zoo’s 18,000-square-foot Ruth Roby Glancy Animal Health Complex, said Dana Kirk, an MSU assistant professor in Biosystems and Agricultural Engineering.
“We are looking to provide about 100-kilowatts an hour,” Kirk said. “That would be enough to sustain the building for about 18 to 20 hours a day, and when there is a lot of activity going on, they will actually have to supplement a little more power.”
Beth Wallace, the zoo’s manager of sustainability, said the biodigester will also produce compost which will be used throughout the zoo and possibly sold to the public.
The biodigester is a part of the Detroit Zoo’s plan to be a zero waste facility by 2020, Wallace said.
“The system will take all of the liquid that we use and reintroduce it back into the biodigestion, or we can use it as a liquid fertilizer,” Wallace said. “So there is little to no negative environmental impact at all. In fact we would argue that it will be a zero waste system because we will use almost of the by-products coming off of the system in one way, shape or form.”
Wallace said some nearby communities and residents worry about the smell of the manure, but that odor control is actually better than the zoo’s current system.
“We currently have an open system for our manure, so we definitely think the system will help control our manure and the smell that comes with it,” Wallace said. “There has been a lot of concern that the nearby communities might smell manure, but it’s a very closed system – more so than what we currently have.”