It may become easier to install and use on-farm biodigesters due to recent regulatory changes implemented by the Ontario government. The annual volume allowance has quadrupled and limitations on types of materials from off-farm sources have been eased. Limits are also being eased for on-farm source materials.
Why it matters: The changes are expected to allow existing and prospective biodigesters to use renewable natural gas as an additional revenue stream.
Typically, on-farm biodigesters produce biomethane through the breakdown of livestock manure and off-farm sources such as food processing waste. Renewable Natural Gas (RNG) is biomethane that has been cleaned and purified to meet natural gas pipeline quality standards and can be interchanged with conventional natural gas as a fuel for transportation and other applications.
However, RNG production from on-farm biodigesters is in its infancy in Ontario.
“British Columbia has kind of led the way in that regard,” says Gord Green, whose family operates a biodigester that produces electricity as its sole revenue stream on their dairy farm near Embro.
RNG is already injected into Ontario pipelines from large-scale industrial and municipal biodigesters in the greater Toronto area, Leamington area and Niagara region. In the short term, regulatory changes should make these operations more cost-effective and contribute to a greater diversion of organic waste.
“The changes will help reduce greenhouse gas emissions by diverting waste from the landfill,” said the government news release. They will “create more opportunities for farmers to treat on-farm materials as well as other types of off-farm food and organic waste materials in on-farm regulated mixed anaerobic digestion facilities. This will enable an increase in on-farm production of biogas to generate RNG.”
Green says the economies of scale needed to pay for specialized equipment to purify and pressurize the gas to pipeline standards put it beyond the reach of most farmers.
On-farm digesters typically yield a 55 to 60 per cent methane byproduct while RNG requires more than 90 per cent methane.
As a result, electricity generation is the main revenue stream for Ontario’s approximately 40 on-farm biodigesters.
The recent changes came about after a January 2020 government discussion paper and stakeholder consultation sessions. They increase the annual allowable off-farm source volume to 40,000 from 10,000 square metres for those operating under the 2002 Nutrient Management Act (NMA) who do not apply for higher-volume approval under the Environmental Protection Act.
Additional types of “de-packaged and specified source-separated organics, such as residential food waste” will also be permitted, according to information provided to Farmtario by the communications office of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).
Higher volumes and a greater range of off-farm materials are already allowable through EPA approval but that comes at significant additional expense for the biodigester owner.
“A farmer could (acquire EPA approval) but there’s quite a bit of effort and expense,” Green said, adding he’s not aware of any on-farm biodigester now operating outside NMA regulations.
According to the government news release, “the regulation changes will enable Ontario’s $35 million-a-year biogas sector to grow by up to 50 per cent over the next five years.”
While much of that growth will initially come at industrial sites, Green predicts it could also “make it easier for farmers to scale up” if it is easier to connect with pipeline infrastructure.
A representative for the Canadian Biogas Association agreed the changes mean that “on-farm anaerobic digesters can (now) be designed, built and operated to produce RNG more economically, while simultaneously offering other value-added benefits such as recycling of organic materials supporting a circular economy (and) improving soil health with digestate.”
But the biogas association also says the changes are only one piece of the puzzle. It called on the government to follow through on commitments made in its Made in Ontario Environment Plan to eliminate the dumping of food wastes in landfills. Those wastes should instead be directed to biodigesters, the association says.
Green says any diversion of food wastes must come with additional resources and rules to ensure the product is clean.