A comparison of the life-cycle greenhouse gas emissions of European heavy-duty vehicles and fuels

This study is a life-cycle comparison of the greenhouse gas emissions from combustion, electric, and hydrogen trucks and buses in Europe. The analysis evaluates the lifetime emissions of different powertrains on a fully harmonized basis, comparing both the emissions attributable to fuel production and consumption as well as the emissions attributable to the vehicle’s manufacturing. It investigates the current best-in-class diesel models against their natural gas, battery electric, and hydrogen fuel cell electric alternatives in the European market.

The key findings of the report are the following:

• Battery electric trucks and buses outperform their diesel, hydrogen, and natural gas counterparts in reducing GHG emissions over their lifetime. 2021 vehicle models produce at least 63% lower lifetime emissions compared to diesel even when using the EU’s average electricity grid mix, which is not fully renewable but will continue to improve during the lifetime of the vehicles. Projections show a 92% emission reduction when 100% renewable electricity is used.
• Fuel cell electric trucks and buses run on hydrogen produced from fossil fuels reduce GHG emissions by 15% to 33% compared to their diesel counterparts in a lifecycle analysis. The emissions reduction depends heavily on the source of hydrogen, which is mostly produced from natural gas today. With hydrogen solely produced with renewable electricity, emissions fall by up to 89%.
• Natural gas trucks and buses provide marginal GHG reductions, at best, compared to diesel. For the 2021 scenario, we find that natural gas trucks and buses may reduce emissions from 4% to 18% compared to their diesel counterparts.
• The biggest portion of lifecycle GHG emissions produced by trucks and buses over their lifetime corresponds to the use (or fuel consumption) phase, not vehicle manufacturing. For diesel and natural gas trucks, the consumed fuel accounts for over 90% of their lifetime emissions. Thus, the higher vehicle and battery production emissions of battery electric trucks are offset by their high efficiency and low lifetime fuel cycle emissions.

Note: This report was updated on 14 August 2024 to correct a small miscalculation of the per-tonne manufacturing emission factor for vehicle gliders. This change reduced the manufacturing emissions across all vehicles by approximately 15-40 gCO2e/km, depending on vehicle category, though the relative emission savings between different powertrain and fuel combinations remained consistent after this change.

Read the press release here.

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