Replacing fossil fuels in the transport sector by renewable energy will help combat climate change. However, lowering greenhouse gas emissions by switching to alternative fuels or electricity can come at the expense of land and water resources. To understand the scale of this possible trade‐off, we compare and contrast carbon, land, and water footprints per driven km in midsize cars utilizing conventional gasoline, biofuels, bioelectricity, solar electricity, and solar‐based hydrogen. Results show that solar‐powered electric cars have the smallest environmental footprints per km, followed by solar‐based hydrogen cars, and that biofuel‐driven cars have the largest footprints.
The environmental performance of different cars depends on the choice of energy source. We show inherent tradeoffs between land use, water use and carbon emissions. From the environmental footprint perspective, solar‐powered battery‐electric vehicles are the most resource efficient per unit of distance, followed by solarbased hydrogen‐driven vehicles. Biodiesel has the worst resource use efficiency per unit of distance while bioethanol has smaller emissions compared to fossil fuels but has extremely large land and water requirements. The logical choice of future transport is thus diffusion of electric and hydrogen vehicles based on (non‐biomass) renewable energy sources.
© 2020. By the authors.
This research received funding from the European Union's Horizon 2020 research and innovation programme MAGIC.
Holmatov, B. & Hoekstra, A.Y. (2020). The environmental footprint of transport by car using renewable energy. Earth's Future, Volume 8, Issue 2.