Use of electric vehicles or hydrogen in the Danish transport sector in 2050? Use of electric vehicles or hydrogen

Denmark has an ambitious long-term goal to reduce greenhouse gas (GHG) emissions from the transport sector with an overall climate target to be independent of fossil-fuel consumption by 2050. We compare a likely scenario with two alternative ways to achieve the goal—either with a high percentage of electric vehicles (EV) or with a high percentage of hydrogen use for transportation. The STREAM model—an energy scenario simulating tool—is used to model the different scenarios and their integration with the electricity and heating systems. The major findings are that an increased share of EV can reduce the socioeconomic cost of the energy system in 2050. However, electricity demand for H2 generation via electrolysis is more flexible than EV charging and the production can therefore, to a larger degree be used to out-balance variable electricity surplus from a high share of wind energy in the power system, reducing the investments in backup capacity. Whether the hydrogen scenario (H2S) is more costly to implement than the EV scenario (EVS) mainly depends on the technological development—especially the improvement on the efficiency of the conversion from electricity to H2 and the cost of the hydrogen fuel cell vehicle. Therefore, the major drivers of a successful H2S are a high efficient flexible H2 production in 2050 and lower vehicle costs, which increase the stability of the power grid, compared to the EVS. Hence, from a socioeconomic view point, the technological path in innovation to achieve fossil-free transport systems should have vehicle costs and electrolyzers efficiency as their main drivers toward 2050.