An increasing number of farms in Ontario and Canada are turning to cow poop for energy…. Before your imagination runs wild—let me explain. Traditionally, animal manure is used on farms as fertilizer, as it is rich in nitrogen, phosphorus, potassium, and other nutrients that crops require. With the rise in farms and livestock resulting from rapid population growth over the past decade, farmers now have to find alternative methods of manure management to deal with the increase in livestock manure.
Instead of disposing of the excess manure as waste, some Canadian farms are starting to harvest the stored energy in the manure by converting it into biogas (a renewable gas composed mainly of methane and carbon dioxide), and digestate (a solid or liquid byproduct that can be used as compost or animal bedding).
Benefits of biogas systems:
The process with which biogas systems convert animal manure to gas is called Anaerobic Digestion (AD). AD has numerous benefits beyond improving overall manure management. Environmentally, it provides benefits such as greenhouse gas reductions (by managing methane emissions), manure odour control, and pollutant and run-off reduction.
Economically and financially, AD can directly benefit farmers by reducing the need to purchase electricity from utility companies, diversifying their revenue sources through supplying the energy created to Ontario’s Feed-In-Tariff (FIT) program, as well as providing employment opportunities to community members. By delivering reliable and dispatchable electricity to the grid, these projects are also helping Ontario move towards a cleaner and more sustainable energy system.
Case studies in Canada:
Greenholm Farms is a dairy farm with 210 cattle that built the first biogas plant in Oxford County, Ontario. It is fueled mainly by cow manure and generates 250kW of electricity, which it then supplies to Ontario’s power grid through their small FIT contract. The electricity generated from their biogas plant powers approximately 200 homes in and around Woodstock, Ontario. The heat generated is re-used in the biogas plant to make more methane, on site to heat water, as well as in their greenhouse.
Maryland Farms is a dairy farm with 250 milking cows in Lindsay, Ontario, that has been producing up to 500kW of electricity from their biogas plant since 2012. James Callaghan, the owner of the farm, says that this is not only helping his farm generate additional income, it is also more beneficial for the environment as most of the pathogens and odour in the manure is eliminated in the process.
As such, spreading digestate from the AD process onto the fields is much less likely to cause pollution in local waterways compared to raw manure. The waste heat from the biogas plant is used to heat Callaghan’s house and several of the farm’s buildings.
Windmill Holsteins is a dairy farm in Shubenacadie, Nova Scotia with about 350 cattle that is harnessing the power of their cow manure. They are also the only biogas dairy farm in the Maritimes. When the farm first started doing this, Richard Metcalfe, biogas co-ordinator at the farm, was repeatedly told that it couldn’t be done.
His successful biogas plant now provides power for 250 homes in the Shubenacadie area, proving naysayers wrong. The biogas plant also provides heat to the family home and prevents waste from being dumped into their backyard lagoon, which can create some pretty unpleasant odours.
Seabreeze Farm in Delta, BC is profiting from both its dairy milk as well as its manure. Since 2012, this farm has been working with CH Four Biogas, a engineering firm in Coquitlam that specializes in anaerobic digestion systems. The biogas that is generated is purified to pipeline quality and sold to Fortis BC as renewable natural gas, which has properties similar to those of conventional natural gas.
Even though it is more expensive, many British Columbians are undeterred and continue to demand for this blend of natural gas that is healthier for the environment.
ZooShare is a non-profit organization in Ontario that is developing North America’s 1st zoo-based biogas plant, which turns poo from the zoo animals into power. Every year, they will recycle 3000 tonnes of animal manure and 14000 tonnes of inedible food waste into 4.1 million kWh of renewable energy for Ontario’s grid through the FIT program.
ZooShare is not only generating power from this operation, they are also a community-based cooperative that provides returns to members who invest in their bonds, at an annual interest rate of 5% over a 5-year term.
Other types of renewable energy in agriculture:
Biogas systems are not the only source of renewable energy on farms. Many Ontario farmers have taken advantage of the FIT program to build small solar PV systems on their farms, and farmers often benefit from land leases with wind developers.
The sun is a constant and reliable source of energy. European experience has shown that the best location to build solar energy systems is in rural areas where there is low air pollution, making solar power collection more efficient. Southern Ontario has relatively high solar potential which means that- when combined with rising energy prices and the growing energy demand— solar arrays in farmlands may soon become a common sight in our province. Different ways that farmers can harness that solar energy include solar photovoltaic systems for electricity generation, solar hot air systems and solar hot water systems.
Since wind turbines need to be located in large areas of open space with a consistent wind resource, farming regions are usually prime locations for wind energy generation in Southern Ontario. In these areas, wind farms are developed both by private investors as well as co-operatives that include farmers. Farmers can either consider small-scale wind energy for domestic use on their farms, or lease their land to commercial wind power developers to generate income.
Another emerging trend is harvesting the energy in crops- such as corn and soybeans—or from other biomass like wood waste and switchgrass for electricity. This is called biomass energy or bioenergy. Energy from these sources can generate power in high efficiency combustion systems to produce heat, electricity, or biofuels. The renewable feedstocks for biomass combustion systems can be readily grown in rural Ontario. Benefits of these systems include provision of a cheap fuel source, reduced reliance on fossil fuels, and capacity for farmers to be self-sufficient in energy production.
Renewable energy is quickly becoming another “crop” that Ontario farmers can harvest. The opportunities are endless, and with the advancements in technology, there is no doubt that we could see a future where farms will not only be producing food for human consumption, but also play a part in providing for our global energy needs.
Header Image source: “Arreton: Anaerobic Digestion Plant” by Flickr user Keith Murray, licensed under CC BY-NC-ND 2.0