Well-to-wheel greenhouse gas emissions of heavy-duty transports: Influence of electricity carbon intensity

•The WTW GHG emissions of vehicle fuels depend on the electricity carbon intensity.•Fuels requiring a lot of electricity are not necessarily better than fossil fuels.•Decarbonizing the transport system is easier in regions with low-carbon electricity.•Bio-CNG and ethanol have very low GHG emissions for all studied applications.•Electric engines are more favorable in driving cycles with many starts and stops. There are several alternatives for how to phase out diesel in heavy-duty transports, thereby reducing the sector’s climate change impact. This paper assesses the well-to-wheel (WTW) greenhouse gas (GHG) emissions of energy carriers for heavy-duty vehicles, analyzing the effect of the carbon intensity of the electricity used in production. The results show that energy carriers with high electricity dependence are not necessarily better than diesel from a WTW perspective. In particular, fuels produced through electrolysis are not well suited in carbon-intense electricity systems. Conversely, waste-based biofuels have low GHG emissions regardless of the electricity system. Battery-electric buses show a large reduction of GHG emissions compared to diesel buses and many other alternatives, while battery-electric trucks have higher GHG emissions than diesel in carbon intense electricity systems. Thus, electrifying transports or switching to renewable fuels will not suffice if the electricity system is not made renewable first.