Renewable natural gas helps advance decarbonization—and Mont-Tremblant’s buses

At Énergir, we often talk about renewable natural gas (RNG) as the energy of the future because it can replace fossil fuels and thus help reduce our collective carbon footprint. The municipality of Mont-Tremblant is well aware of this potential, and in May 2024 will officially open the first-ever free public transit line in Quebec using compressed renewable natural gas (C-RNG) buses. A small step for passengers, a big step for decarbonization, one might say, as this innovation foreshadows the potential for RNG in the public transit sector.

A clear choice for the municipality

This initiative was made possible through a collaboration between the City of Mont-Tremblant, Groupe Galland (the bus operator), Énergir and Investissement Québec, with a view to reducing the city’s carbon footprint and providing more sustainable mobility. “Our buses cover an average of twelve 50 km routes per day, for a total of 600 km every day,” said Dominique Laverdure, Mont-Tremblant’s deputy mayor. “So we had to choose the solution that offers the most benefits in terms of energy expenditure, refuelling time and costs.”

Paving the way for public transit

To refuel its vehicles, Groupe Galland has also built a C-RNG pumping station in Mont-Blanc, a few kilometres from Mont-Tremblant. Connected to Énergir’s gas distribution system, this station will contribute to the development of RNG purchasing in Quebec in a sector where it can have a considerable impact. “Transportation is Quebec’s biggest decarbonization challenge, accounting for 43% of greenhouse gas emissions,” explained Renault-François Lortie, Vice President, Customers and Gas Supply at Énergir. “We are therefore proud to have worked with our partners to implement the very first public transit line in Quebec to be powered by compressed renewable natural gas. RNG plays a key role in Quebec’s energy transition. This is true not only for the building and industrial sectors, but also for the transportation sector.”

Waste that goes a long way

Over a 10-year period, it is estimated that the five C-RNG buses that will serve Mont-Tremblant and the surrounding area will prevent the CO₂ equivalent of 7.5 million kilometres driven by car. When you consider that RNG is produced from table scraps and agricultural residues, it’s an excellent way of recovering the emissions from our waste material to help propel Quebec’s energy transition.

How is renewable natural gas produced?

Renewable natural gas is a 100% renewable-source natural gas derived from the decomposition of organic materials such as food waste, cattle manure and slurry, and wastewater from sewage treatment plants. These materials are collected and sent to a biomethanation plant.

They are then placed in biodigesters, huge tanks that work like a stomach. Microorganisms break the materials down into biogas, which is then purified into RNG and injected into Énergir’s gas distribution system, thereby contributing to the collective decarbonization effort across Quebec.

Biomethanation also produces an earthy residue called digestate, which is used as a natural fertilizer for crops.