By Jody MacPherson
This article appeared originally in C3 Views Newsletter, a publication of Climate Change Central
From Heaps to Heat: Manure as a Power Source
It’s often the subject of derisive jokes and schoolroom giggles. We’re annoyed when we step in it and offended by its odour. But it may be time to start thinking of manure a little more impartially.
Every day, tonnes of the steaming mixture are deposited on farms across Alberta by a variety of livestock. Even after spreading the copious compound to fertilize the fields, there is often so much left that it has to be
stockpiled. There’s a growing realization these mounds of malodorous mulch could be put to better use.
And then there’s the issue of greenhouse gases. It’s estimated the agricultural sector is responsible for approximately 10 percent of Canada’s greenhouse gas emissions. The Alberta Research Council says manure
management practices could produce about 16 percent of that amount.
Scientists have long known those heaps of barnyard dung release harmful methane and nitrous oxide gases to the atmosphere. But now, a small group of farmers, researchers and entrepreneurs are working hard to come up with solutions that reduce these emissions and are at the same time economic. One idea is to take the manure and convert it to heat and electricity, turning it into a renewable energy source. The most promising technology uses bacteria that are among the oldest life forms on earth. The bacteria don’t need oxygen and decompose organic matter using the same process that created the earth’s coal and oil deposits and the natural gas we use today. This process of “anaerobic digestion” can be duplicated using a mechanical digester. But the technology is expensive and the experts agree the up-front capital investment is
Ian Potter, director of Sustainable Energy Futures for the Alberta Research Council says that industry and government have invested substantially into renewable energy research over the last two decades, but with a couple of exceptions, the majority of technologies have failed to gain market acceptance, mainly due to economics. Manure to energy, he says, is probably one of those exceptions.
Self-reliance is important to a lot of confined feeding operations (CFO) and by using manure to generate power, they reduce their need for waste disposal as well as their need to purchase power from the grid. A lot of CFO operators are very entrepreneurial and can see the value-added of using by-products to generate revenue or reduce costs.
Potter says the agricultural industry is more interested in alternative energy sources now because they can see an opportunity to add value to their existing operations, but few would do it solely to help meet the
Kyoto Protocol requirements.
“Some groups and individuals say the government needs to provide incentives,” he adds. “For example, environmental loan guarantees by governments to assist livestock producers in making large capital investments for environmental improvements, or premium buy-back rates for “green”/renewable forms of energy.”
The cost for implementing a manure to energy system could be in the millions of dollars for the average feedlot, Potter says. Once the digester is built though, the maintenance costs are relatively cheap.
John Kolk, who runs a cow/calf feedlot near Lethbridge and broiler chicken farm just east of Calgary compares the transition into a new technology to that of deep plow to a minimum tillage practice.
It’s a lot like when the farmers first came out west and tried to use eastern farming methods on the dry, prairie fields. Back then, someone realized you couldn’t deep plow the fields every year because of moisture loss
and wind erosion and came up with the idea of minimum tillage (where you hardly disturb the soil).
Very few people were willing to experiment with minimum tillage back then, but now with the improved technology and local demonstration sites, it’s pretty much becoming standard practice.
Kolk says the idea of converting manure to energy is still in the early stages and has a long way to go before being widely accepted by farmers. He’s not convinced all the pieces of the technology have come together yet.
Yet, he also says the awareness is increasing and he has personally received more calls about manure management and energy production in the last five years than ever before. Part of the reason could be that in the past, inexpensive utilities made it easier to run an electrical or gas line to a barn, but now deregulation and higher energy costs make the investment look a lot better.
The technology is getting better and research is bringing down the size requirements so it can be economical for smaller operations, he says. It starts with awareness bringing the idea to people, getting them in the same room and having a discussion.
You can’t expect farmers to jump from consumers to producers overnight. It involves changing their whole orientation, their way of looking at things. Kolk says farmers have been hit hard by severe weather
over the last few years, especially the drought, and recognize the impact of climate change issues. He says the time is right and he’s anxious to see Alberta get started with some projects.
It’s always a high risk to be the first one to try something new, says Kolk. Clearer rules and clarification of risks will start to drive interest.
Kolk says farmers want to do the right thing for the environment, but it has to be economically feasible as well. He’s been farming on the same land his grandfather bought in the 1950’s and says they’ve always thought
it was important to take care of the resources.
“Up until recently, we’ve always looked at coal, natural gas and oil as our trump card in Alberta,” he says. “We need to get serious about leading in some of these other energy areas. We need to put a few more resources
into it and become a world leader.”
In fact, Potter says there are thousands of anaerobic digesters chewing away on manure in Europe already. And not just larger farms are doing it. He says a lot of the feedlots in
Europe using digesters are smaller, supported in part by strong green government policies.
The technology can work with smaller operations, says Potter. Small farmers don’t have to do it on their own. There are opportunities for
feedlot operators to combine resources and look at innovative ways of sharing costs and systems.
As an example, he says a group of small farmers in the same geographical region could pool resources and form a holding company to own the digester, produce the power and sell it back to the individual farmers at a subsidized rate, exporting the excess power to the grid.
While there are some economic hurdles of turning manure heaps to heat, there is considerable effort to making this a reality. Perhaps in the not too distant future, manure to energy will be thought of in the same light as coal, oil or natural gas. More likely it will be a by-product that reduces costs and makes this industry more competitive.