Flexible sector coupling with hydrogen: A climate-friendly fuel supply for road transport

The substantial expansion of renewable energy sources is creating the foundation to successfully transform the German energy sector (the so-called ‘Energiewende’). A by-product of this development is the corresponding capacity demand for the transportation, distribution and storage of energy. Hydrogen produced by electrolysis offers a promising solution to these challenges, although the willingness to invest in hydrogen technologies requires the identification of competitive and climate-friendly pathways in the long run. Therefore, this paper employs a pathway analysis to investigate the use of renewable hydrogen in the German passenger car transportation sector in terms of varying market penetration scenarios for fuel cell-electric vehicles (FCEVs). The investigation focuses on how an H₂ infrastructure can be designed on a national scale with various supply chain networks to establish robust pathways and important technologies, which has not yet been done. Therefore, the study includes all related aspects, from hydrogen production to fueling stations, for a given FCEV market penetration scenario, as well as the CO₂ reduction potential that can be achieved for the transport sector. A total of four scenarios are considered, estimating an FCEV market share of 1–75% by the year 2050. This corresponds to an annual production of 0.02–2.88 million tons of hydrogen. The findings show that the most cost-efficient H₂ supply (well-to-tank: 6.7–7.5 €/kg_H2) can be achieved in high demand scenarios (FCEV market shares of 30% and 75%) through a combination of cavern storage and pipeline transport. For low-demand scenarios, however, technology pathways involving LH₂ and LOHC truck transport represent the most cost-efficient options (well-to-tank: 8.2–11.4 €/kg_H2).