While the EU Commission is preparing a draft on future emission standards for heavy-duty trucks and buses (HDVs), the International Council on Clean Transportation (ICCT) has published in a white paper its findings comparing life assessment greenhouse gas emissions of diesel, gas, bio-fuel, battery-electric, and fuel cell heavy trucks.
And the clear winner is… no surprise: the battery-electric truck. Battery electric HDVs bought today allow for greenhouse gas (GHG) emission savings of 63% or more over their life cycle compared to conventional ICE HDVs. And that percentage will be even more outspoken by 2030, averaging 75 to 92% considering the sources of the electricity mix.
ICCT compared current best-in-class Euro 6 diesel-fueled trucks to a natural gas (NG)-fueled variant, eventually with a blend of biofuels and two zero-emission types: pure battery electric and hydrogen fuel cell electric. And they did the same exercise for the different types of trucks manufactured in 2030, with the expected technological improvements (Euro 7).
The researchers investigated the emissions over each vehicle’s total lifetime for three common HDV categories: a 12-tonne truck, a 40-tonne articulated tractor-trailer, and an urban bus.
They are taking into account not only tailpipe emissions but also the carbon footprint of the manufacturing process of the vehicles and their components, vehicle maintenance, fuel production, and electricity production.
Depending on the energy source
For the battery-electric truck, calculations are made using either grid or 100% renewable electricity. For the fuel cell truck, hydrogen produced from natural gas is compared to ‘green hydrogen’, using renewable sources of electricity.
In 2022, wind and solar generated a record fifth of the EU’s electricity mix (22%), for the first time overtaking fossil gas (20%) and remaining above coal power (16%), according to the latest figures of independent energy think tank Ember.
Nuclear and hydropower combined dropped by 7% to around 32%, caused by a one-in-500-year drought which led to the lowest level of hydro generation since at least 2000, and widespread unexpected French nuclear outages. By 2035, wind and solar power are expected to deliver 75% of the energy mix, with fossil fuels (merely gas) dropping to 5%.
All these parameters taken into account, ICTT came to several key findings that show a clear path for the battery-electric truck and the fuel cell truck to be the outspoken winners of the ecological race.
A battery-electric truck (BET) accounts for lifetime emission savings ranging from 63% to 76%, based on vehicle type, when EU grid average electricity is used. However, the whitepaper states that these emissions savings can increase to 92% when that electricity comes from purely renewable sources. By 2030, the BET will average 75% to 82% of savings over ICE trucks as the percentage of renewables in the grid’s electricity mix evolves.
The origin of hydrogen is crucial
For fuel cell trucks, the origin of the hydrogen used is crucial. Today’s FC HDV saves up to 89% relative to a conventional ICE HDV when using green hydrogen, close to the battery-electric truck powered by renewable energy. But when that (grey) hydrogen is made from natural gas without capturing the CO2 in the process, the savings drop to 15%.
Natural gas HDVs, at best, provide marginal GHG emission savings, a lifetime emission reduction from 4% to 18% compared to diesel HDVs, says ICTT. “Additionally, we find that the small emissions savings from using natural gas in HDVs are lost when considering the short-term climate impact of methane emissions. We estimate that compressed natural gas and
liquefied natural gas (LNG) have a 0% to 21% higher climate impact than diesel ICE HDVs for 2021 vehicles, largely due to upstream methane leakage.”
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