To guide the energy transition, initial steps should promote hydrogen by establishing a favorable market environment, encouraging research and innovation and establishing viable transport and distribution networks.

Both Distributed Energy and Global Ambition scenarios show how under normal conditions, without any supply disruption cases, the H₂ Infrastructure Level 2 achieves higher CO₂ savings compared to H₂ Infrastructure Level 1.

The total CO₂ emissions are thereby calculated by applying an assumed specific emission factor¹  to the consumed hydrogen, or the produced hydrogen from SMR with CCS, as well as to the consumed natural gas (except for national production of ­biomethane and synthetic methane based on power-to-gas). The fact that hydrogen demand is curtailed to a considerable extent, especially for H₂ Infrastructure Level 1, causes some uncertainty over the total emissions calculation. In H₂ Infrastructure Level 2, the missing hydrogen is produced using methane, to the extent possible, on top of the potential maximum SMR defined by the scenarios.

However, also other fuel-switches are thinkable, resulting in different emission factors and thus ­different total emissions. In the following graphs, the curtailed demands for hydrogen and methane per year, per scenario, and per infrastructure level combination are provided. To make the results between the infrastructure levels comparable for this exercise and not to reward demand curtailments by attributing them with 0 emissions, the curtailed H₂ demand is multiplied by the emission factor for SMR with CCS and the curtailed CH₄ demand is multiplied by the emission factor of natural gas. Thus, the difference in emissions displayed in the graphs is solely linked to the ability of the different infrastructure levels to use electrolytic hydrogen produced from non-CO₂-emitting sources instead of hydrogen from SMR with CCS. If the curtailed hydrogen demand had been assumed to be substituted by other sources, e. g., by non-abated SMR, or simply had remained in the methane market, the resulting emissions would be much higher.

All graphs displayed in this chapter show ­combined CO₂ emissions from methane and hydrogen for the Reference case.

H₂ Infrastructure Level 1 results show a slight demand curtailment in all Europe for Distributed Energy and a higher one, above 10 %, for ­Global Ambition. Without this demand curtailment ­higher CO₂ emissions would be expected for both ­scenarios.