What is the best alternative drive train for heavy road transport?

Ambitious long-term green house gas (GHG) emission targets require decarbonisation of the transport sector. For road transport, passenger cars with internal combustion engines need to be replaced by electric vehicles. However, despite its growing share of transport's CO2 emissions, no clear solution presents itself for CO2 emission reduction on heavy road transport. Potential CO2 free options include direct electrification of trucks via batteries, over-head power lines, hydrogen and other power-to-X fuels from renewable electricity. Here, we compare these options with respect to their degree of technological readiness, costs and CO2 reduction potentials. We use cost assumptions and cost reduction potentials from available literature sources and combine them with today's heavy truck usage data for Germany in 2030. Our results show that the high efficiency in direct usage of electricity from overhead cables implies less installation of additional renewable power compared to fuel cell electric vehicles. Both could be good long-term solutions but require a massive initial infrastructure investment.