Debunking the myth that electric trucks and buses are not cleaner than diesel

Unlike conventional vehicles, electric vehicles (EVs) don’t physically emit CO₂. But they’re not completely emissions-free: there may be greenhouse gas emissions associated with making and disposing of them, as well as emissions from generating the electricity they use.

These indirect emissions are often the focus of those who argue that manufacturing an EV produces more greenhouse gasses than non-EVs.

However, research usually shows that EVs are better for the environment than conventional vehicles. In almost all scenarios, electric cars still lower emissions compared to conventional cars: but different studies come up with different amounts by which EVs improve things.

And now this new report from the International Council on Clean Transportation has thrown trucks and buses – some of the dirtiest vehicles – into the mix and discovered that electric heavy vehicles too are cleaner than conventional vehicles.

The report finds that, in Europe, battery-powered trucks and buses deliver the biggest emissions reductions over their lifetimes, compared to hydrogen, gas, and diesel vehicles.

Trucks and buses make up 2% of vehicles on Europe’s roads, but a quarter of its transport emissions.

The researchers found that, including manufacturing, a battery-electric 40-tonne semi-trailer entering service in 2021, would produce at least 63% lower emissions compared to diesel over its lifetime.

This also accounts for Europe’s non-emissions-free electricity grid. If using only renewable electricity, such a vehicle would provide an 84% emissions reduction.

Hydrogen fuel vehicles using emissions-heavy hydrogen are 15% less polluting than diesel cars. Using hydrogen made only from renewable electricity (green hydrogen), hydrogen vehicles can lower their emissions by 85%.

Trucks and buses powered by fossil gas (also called “natural gas”) only provided a 4-18% reduction in emissions compared to diesel. This gas is mostly methane, which is itself a potent greenhouse gas, as well as combusting to make CO₂.

“The climate benefits of natural gas urban buses compared to diesel are marginal at best,” says Nikita Pavlenko, Fuel Program Lead at the International Council on Clean Transportation.

“Methane leakage may undermine the benefits of transitioning bus fleets to natural gas. Cities should consider their transport policy strategies with these numbers at hand.”

Felipe Rodríguez, also a program lead, says that increasing energy efficiency is the main reason battery electric trucks and buses have the lowest lifetime emissions impact.

“Our study addresses the uncertainties surrounding the share of emissions in all stages of the vehicle’s life,” says Rodríguez.

“It shows that only battery electric and some fuel cell electric trucks can meet the climate targets in the sector.”