Farming Manure for Megawatts

By Heather Travis
Westerr News
Thursday, January 7, 2010

In a few years, a herd of Holstein cows might be powering the village of Ilderton. This is not so far-fetched, as a locally owned farm has begun turning manure into an energy resource with the help of university researchers.
In 2006, the urban sprawl of London, Ont. forced the Stanton family farm to relocate from Hyde Park to its current location near Ilderton.

Laurie Stanton and his wife Sandy, along with their children Jeff, Jim, Greg and Amy, decided this change afforded them an opportunity to rebuild their dairy operation from the barn floor up to operate efficiently and in an environmentally friendly manner.

The more than 2,000 dairy cows at Stanton Farms are valued for more than just milk. Researchers are working with the Stanton family to turn manure into electricity.

The result? Well, this is not your grandfather’s farm. Forget those sepia-toned images of farm life. The Stanton operation is a sleek, mechanized business that brings advanced technology and business practice to a sector that has long wrestled with the need for change.

“The way we look at it, agriculture is changing and larger farms are the standard rather than the exception,” says Laurie. “We wanted to do everything well ... We also want to have as little impact as possible on our neighbours.”
The farm has more than 2,000 cows, including those used for dairy production and a genetics and breeding operation.

While cattle manure is often used as a crop fertilizer, the family wanted to investigate whether the traditional waste product could be put to other uses.

The Ontario government invested $2.5 million for the completion of a biogas demonstration facility at Stanton Farms, which was developed in collaboration with The University of Western Ontario, the University of Guelph and the University of Waterloo.

All of the cow manure and on-farm wastewater is processed through the biogas system to generate methane gas.
“We’ve taken what some may see as a problem – waste that’s generated and turned it into a valuable by-product with a greater community-wide benefit,” says Garry Fortune, a consultant for Stanton Farms.

A contentious issue in the area of generating alternative fuels has been the use of crops that are also a food source for fuel, such as converting corn into ethanol.

By generating biogas from manure, Stanton Farms can fuel its operation without relying on non-renewable resources or competing with the food supply. In addition to manure, the farm also processes off-farm waste, such as biodegradeable material from grocery stores.

“We want to create valuable products out of low-value products ... We would sooner utilize farm waste or products than valuable products,” says Laurie. “That’s much more sustainable long-term than the other approach.”
Aside from its unpleasant smell, manure used as fertilizer produces methane, a more potent greenhouse gas than carbon dioxide. By putting manure through the biogas process, methane is contained and burned as energy.
The process kills pathogens that can foul the water system and, as a bonus, odour is virtually eliminated.
The farm can produce 300 kilowatts of electricity daily and has the capacity to ramp up production to 1.3 megawatts, enough power for the town of Ilderton or more than 800 homes.

How does the process work?
Manure is collected from barns and deposited into troughs, much like an urban sewage system. Farm wastewater is captured and used to flush the troughs, bringing the waste to the facility to be processed by the digester tanks. Manure solids are pumped into a mixing tank and combined with off-farm organic waste, which is continuously pumped into the eight digester tanks. The anaerobic digestion process produces methane gas.
The gas is collected and burned in a cogeneration system to produce electricity supplied to the neighbouring community.
“We are the reliable renewable energy,” says Fortune. “Here we are at maximum capacity 24-7, so we are a much more reliable source of generation.”
Heat generated from burning methane gas in the cogeneration system is recaptured and used to heat the biogas building, the waste material for processing and the hot water for the farm’s in-floor radiant hot water system that heats the building during cooler seasons.
The nutrient-rich liquid byproduct of the processed manure is virtually odourless and can be used as an organic fertilizer.
Engineering professor and Associate Dean (Academic) Amarjeet Bassi is among the researchers using Stanton Farms as a large-scale test tube.
In collaboration with Stanton Farms, Bassi is testing the liquid byproduct as a nutrient source for growing microalgae (chlorella) to produce oil, which can be converted to bio-diesel. The leftover algae is food and a high-value protein supplement. Leftover water can be cleaned and used as drinking water for the cows.
This year, Bassi will take what he has learned in his Western lab and transfer it to a pilot-scale system on the farm.
Bassi will build a greenhouse with a bio-fence of five gallon tubes filled with microalgae grown on 5,000 litres a day of effluent (treated wastewater rich in fertilizer value). The algae production process uses minimum energy – using only natural light, carbon dioxide captured from burning the methane gas, and waste effluent – to produce a high-value product, he says.

“We are closing the environmental loop on the farm so they actually have no waste,” says Bassi.
There is a strong push in the United States for dairy farms to have anaerobic digesters because of the energy production and the environmental benefits in reducing greenhouse gases, says Laurie. Stanton Farms is the largest of six agricultural biogas facilities in Ontario.
But, before the farm starts powering lights in the neighbouring community of Ilderton, a few issues need to be worked out and a contract must be struck with the Ontario Power Authority to get their power onto the grid.
Meanwhile, the Stanton family continues to collaborate with researchers to keep the farm operation abreast of the changing agricultural landscape. Working with Bassi is one way the family is making farming more environmentally friendly.
“From getting something that works in the lab, it’s a big step to getting it to something that will work commercially and if that step isn’t taken, to some extent that research will be wasted,” says Laurie. “When we bring the two elements together, it could go on and be commercially viable and be a win for both ourselves and Western.