To produce zoo biogas makes a great deal of sense in a world seeking ways to fight climate change. In fact, any zoo produces a lot of organic waste which is ideal for renewable energy production in a “biodigester” or anaerobic digestion facility.
Just visit any of the large animal enclosures at any zoo and your nose will tell you that there is animal waste present! Yes. Poo!
Zoos also produce food waste and other organic waste (biowaste) from:
- visitor pre-catering food preparation
- animal food preparation
- cafe and restaurant scraps, and
- organic waste from park and garden maintenance.
This is a ready source of supply for an anaerobic digestion plant producing renewable energy.
Zoos use a lot of energy, and most have targets that they want to meet to comply with the race to Net-Zero by 2030.
Now watch our video below which we made specially to explain zoo biogas:
We recommend that all zoological organisations consider building and operating a biogas plant to:
- treat their organic waste and make renewable energy to run the zoo
- bring with it a considerable number of new local jobs
- help publicise the importance of sustainability in energy
- save money on waste disposal and treatment
- win the approval of their visitors: Most zoo attendees will be keen to see that their zoo is doing the best it can to maintain the biological diversity which is threatened by climate change.
- the composted output (digestate) may even be used to:
- Provided bedding for some of their animals
- fertilise the zoological park's gardens (subject to rules on sanitisation).
Read on to find out more about zoo biogas and the successful AD plant at the Detroit Zoo!
Zoo Biogas Plant at Detroit Zoo Turns Zoo Waste into a Natural Renewable Energy Source
The zoo's $1. 2 million anaerobic digester, which was installed in 2017, converts approximately 500 tonnes of their animal excrement and other organic waste into compost.
Excess gas is subsequently converted into an alternative energy source, which is used to power the zoo's Ruth Roby Glancy Animal Health complex.
“most institutions would not even consider putting it in, because the return on investment is quite long,”
Hanbury says of the digester:
“that’s a particular instance where we are a leader in green innovation.
US Zoo is Using Anaerobic Digestion to Reach 100% Renewable Energy Goal
The Detroit Zoological Society (DZS) is pursuing its aim of 100 percent sustainable energy through anaerobic digestion. The zoo in Michigan has already erected an anaerobic digester that takes 500 tonnes of herbivore waste and food scraps from landfill and converts them to energy and compost. In a statement, DZS announced that the company has won four green awards for its sustainability activities and accomplishments.
The zoo has also installed solar and electric hybrid golf carts as well as bicycles for onsite transportation in addition to its anaerobic digestion.
Detroit Zoo Plans to Turn Animal Waste Into Energy
The following is our original article published on 28 April 2015. It is still relevant today:
Anaerobic Digestion to be Detroit Zoo's Newest Attraction and to Use Crowdsourcing
Animal waste is commonly used as fertilizer but it can now be utilized as an endless supply of energy thanks to Anaerobic Digestion. Zoos in the U.S. on average each create around 400 tons of animal waste a year and that amount of waste can easily be processed and used to provide at least 10% of their energy needs.
The Detroit Zoological Society is the first in the U.S. to take advantage of Anaerobic Digestion by using the waste of zoo animals. It launched a crowdfunding campaign for its Detroit Zoo AD plant last week. It is hoping to save at least $80,000 yearly in the facility’s energy costs, as well as about $40,000 in waste disposal.
The Detroit Zoo also plans on reducing its greenhouse gas emissions by 20% this year and has a goal to achieve zero waste by 2020.
“We’ll be the first zoo in North America to have a dry biodigester on grounds, turning the dry animal waste into electricity,”
said Gerry VanAker, the Chief Operating Officer of the Detroil Zoological Society.
“There’s also a zoo in Munich, Germany that operates a biodigester, and the Toronto Zoo is in the early phases of developing one.”
Tell Me More About Anaerobic Digestion
Anaerobic Digestion is a sequence of biological processes in which microorganisms are broken down into biodegradable materials to produce biogas. The biogas is then combusted (burnt) in order for it to generate electricity or heat. The biogas byproduct consists of methane (CH4), carbon dioxide (CO2), and other forms of gases.
Sulzer, an engineering company that is in partnership with Unaoil, says that a successful anaerobic digestion plant requires temperature equalization and the proper homogenization of the biomass. In addition, for the production of high-quality biogas, the formation of floating crusts on the top of the liquid substrate should be prevented, and foam formation must be avoided.
Detroit Zoo’s new biodigester equipment will save on waste disposal costs, and also generate energy, but will have a high initial capital cost, and the Detroit Zoological Society’s existing funding is not enough to purchase it. As a result, the society has started a crowdsourcing operation with a target goal of $55,000 by June 16th.
We think that this use of crowdsourcing was probably another first for the zoo!
[Original article published on 28 April 2015. Updated August 2021.]