Purchase of diesel buses not the better way for TTC

Toronto is currently eyeing a major investment in diesel buses, which would derail progress toward its emission reduction goals and pull a major punch in the fight against climate change.

The Toronto Transit Commission (TTC), the city agency with the highest vehicle fuel consumption and greenhouse gas (GHG) emissions, plans to spend $934 million to buy more than1,000 new buses and revitalize about 700 others — 729 are slated to be diesels, and 254 to be second-generation diesel hybrids.

The trouble is, diesel exhaust is a major emitter of greenhouse gases, nitrogen oxides, particulates, black carbon and other pollutants which damage the climate and public health. Buying new diesel buses locks in their emissions for over a decade.

Much better options exist.

Instead of diesels, the TTC could buy natural-gas buses equipped with “near zero” engines and fuel them with renewable natural gas (RNG), also known as biomethane. Compared to the most advanced diesels, these buses emit a tenth of the smog-forming, asthma-triggering and health-damaging pollutants, while running them on RNG deeply slashes GHG emissions.

RNG is the lowest-carbon fuel available. It’s chemically nearly identical to conventional natural gas, but it’s not a fossil fuel. Made from the biogases emitted by decomposing organic waste, it can be carbon-free or even net-carbon-negative over its life cycle, especially when made from food or agricultural wastes and used to fuel natural gas vehicles.

Today, about 1,000 natural-gas transit buses and heavy-duty trucks operate successfully in southern Ontario. They could all run on RNG.

Surrey, B.C., Grand Junction, Colo., and Sacramento and South San Francisco in California are all producing RNG locally from their own organic waste and using it locally to power transit fleets. So are Oslo, Berlin and many other European cities. Toronto could, too.

It’s the North American leader in diverting organic waste from landfills to dedicated anaerobic digestion facilities, particularly urban food waste. With minor upgrades, Toronto’s Dufferin and Disco Rd. digesters could produce enough RNG to fuel 11 per cent of the city’s bus fleet.

Other local RNG projects in Ontario are ramping up, including at the Ontario Clean Water Agency in Stratford. Natural gas refuelling stations now in place or under development can supply enough RNG for hundreds of city buses and trucks, and companies are eager to build more.

Buying 729 new natural-gas buses with near-zero engines would initially cost TTC $36 million more than 729 new diesels. But that’s a fraction of the $943 million the city and province will spend to replace or refurbish Toronto’s buses.

Over time, lower RNG fuel and operations costs would more than offset it. So adopting RNG buses would not only benefit the climate and public health, it would ultimately cost less than sticking with diesels.

Replacing half of TTC’s fleet with near-zero buses powered by RNG would lower fleet-wide GHG emissions 40 per cent or more, cut health-damaging pollution, and make Toronto a model of a closedloop waste-to-fuel system for urban sustainability. That’s an opportunity the city should seize.