Is biomethane really the Holy Grail for clean energy?

One of Canada's largest biodigesters is taking shape in a field outside High River, Alta., raising with it a growing global debate over natural gas, cattle farming and greenwashing. The project will house a machine that transforms organic matter like cow manure or food waste into biomethane gas.

Biomethane is considered renewable because it is created by capturing methane generated when organic matter like manure and food waste breaks down and transforming it into a fuel that is chemically identical to conventional natural gas. The projects are lauded by gas companies as a clean energy solution, but climate experts say they are little more than greenwashing.

Benita Estes, whose property borders the planned facility, worries about the potential for explosion and possible toxic effluent emanating from the facility. She’s also disgusted by the "nose-burning" stench from cattle in the feedlot producing the manure that will provide the feedstock for the biodigester.

The company says the facility is safe and that once the manure is being used to produce biomethane, the stench will go down. They contend their project will help tackle the climate crisis.

"We are capturing biomethane from livestock waste and other organic sources that would otherwise get emitted in the absence of a digester, which is specifically designed to capture and upgrade the biomethane," said Krasen Chervenkov, executive vice-president of business development and strategy of Tidewater Renewables. A company subsidiary, Rimrock Renewables, is building the High River facility.

Left uncaptured, that methane — a more potent greenhouse gas than CO2 — would otherwise escape into the atmosphere and contribute to global heating. That has encouraged gas companies to invest heavily in biomethane projects, calling the gas "renewable natural gas" and pitching it as a way to reduce emissions while continuing to use natural gas in homes.

This, in turn, has fuelled a growing biodigester industry focused on transforming large amounts of organic waste into biomethane and blending it with conventional gas in the existing pipeline system. These companies then sell the "renewable" designation to natural gas providers under a scheme similar to carbon credits. Governments have also backed the approach, with thousands of biodigesters operating in places like the U.S. and several European countries.

But when biomethane is made with waste from industrial animal farming — itself a major emitter — and excess food typically sourced from grocery stores or food retailers, how climate-friendly is it really?

Critics say the gas and food industries are trading on biomethane’s renewable label as a way to stave off attempts by governments to end the use of gas in homes while deflecting attention from the climate impacts of meat production and inefficient supply chains.

Agriculture is responsible for nearly a third of global emissions, over half of which come from beef and other animal agriculture, while food waste accounts for about six per cent of global emissions.

Reducing these emissions is possible, but claiming that biomethane production can do the trick is a "sleight of hand" to hide the climate impacts of burning the fuel and of harmful food production systems, said food policy analyst Rebecca Wolf with Food and Water Watch, an American environmental organization. Biomethane still generates CO2 when it is burned, she pointed out.

Reducing meat consumption, better using manure to fertilize fields and building efficient supply chains to diminish food waste are more effective methods to reduce food and agriculture emissions, she said.

Natural gas is Canada's most widely used fuel, generating roughly 38 per cent of all energy used in the country, and is responsible for about 22 per cent of global greenhouse gas emissions that cause global heating.

Last year, Tidewater Renewables signed an agreement with FortisBC, the provincial gas utility, to supply the latter for 20 years with enough "renewable" natural gas credits to cover the gas used annually in about 5,800 homes. FortisBC directed questions about the agreement to Tidewater Renewables.

The purchase is part of FortisBC's push against efforts by several B.C. municipalities to ban fossil-based natural gas infrastructure in new buildings in an attempt to reduce emissions. Because renewable natural gas doesn't come from fossilized deposits, the utility argues it should be exempt from the rules.

FortisBC has been fighting to keep its home-heating business. The company in January submitted a proposal to the B.C. Utilities Commission for permission to sell 100 per cent renewable natural gas to every new building in the province. FortisBC also requested permission to expand the types of gas it can call "renewable" to include other gases, like so-called "blue" and "turquoise" hydrogen, made from conventional natural gas. Hydrogen can be blended with natural gas to be used in homes. The proposal is still being assessed by the commission.

The changes are necessary because "federal, provincial and municipal … policies focused on reducing GHG emissions threaten the long-term viability of the gas delivery system," FortisBC wrote in legal filings to the commission. Mandates like the municipal bylaws banning conventional natural gas in new buildings "may cause customers to (stop)" using natural gas entirely unless the utility company can supply them with so-called "renewable" natural gas.

However, a close look at a key study led by the B.C. government and FortisBC that backs the company's proposal shows biomethane — the gas captured from landfills and biodigesters — will likely only ever account for a small fraction of the province's needs.

Globally, the International Energy Agency estimates that biomethane accounts for only 0.1 per cent of natural gas demand.

Chervenkov said though his project's production is "small in comparison to natural gas production (from fossil source), this renewable gas project illustrates how impactful one project could be and why more of these RNG projects are needed."

But Wolf countered that reasoning will inevitably block progress on eliminating two other major sources of emissions: cattle and food waste.

"This model doubles down on industrial agriculture and the need for industrial-scale waste," she said.