ONTARIO — It’s been years since a new, on-farm biogas-fired power project has plugged into the provincial power grid, following the 2016 cancellation of Ontario’s controversial Feed-In Tariff program and related Green Energy Act.
But biogas proponents see a brewing opportunity for farmers still interested in the energy and revenue potential of methane produced from manure: Renewable Natural Gas (RNG).
Rather than being burned in a generator to make electricity, the raw biogas collected in an on-farm digester can be cleaned and injected as RNG into the local natural gas network.
Out of 33 operational farm-based biogas systems in Ontario, only one of them — at Stanton Farms in southwestern Ontario — currently produces RNG that goes into the utility gas grid. Enbridge — the monopoly gas distributor in Ontario — is promoting RNG to consumers willing to pay an extra $2 per month for it.
A number of other non-ag facilities also make RNG from biogas at sewage plants and landfill sites, according to Canadian Biogas Executive Director Jennifer Green, who estimates about 12 to 15 of those producers exist in Canada.
She said that, in the absence of an electricity program in Ontario, RNG is “the featured pathway right now” for anyone looking to sell farm-based biogas as a form of energy. Her organization hopes to see a substantial increase in biogas production from farm manure, she said, as only 5% of Canada’s agricultural biogas potential has been tapped.
A farm digester typically produces biogas with a 50 to 55 % mix of methane plus carbon dioxide and other impurities, she explained. The biogas must flow through a special membrane converter that brings it up to a 90 to 95% methane standard before going into the gas distribution system as RNG. Green suggested the capital cost of a biodigester that outputs RNG would be about the same as the predominant systems that make electricity.
Because the field is so new in Ontario, Green couldn’t put a dollar figure on the revenue farmers might get for RNG sold to Enbridge. However, she reported that Fortis in B.C. pays between $16 and $30 per Gigajoule of energy (a Gigajoule represents just under 27 cubic metres of lgas). In Quebec, gas company Énergir pays the producer between $11 and $22 per Gigajoule.