The report focuses on the analysis of a cost-optimal hydrogen network in Europe within the context of an integrated energy system. It addresses the need for understanding the required capacity and spatial distribution of hydrogen infrastructure to meet the growing demand for clean energy carriers. Previous studies often overlook the integration of a hydrogen network and lack optimized designs considering a sector-coupled energy system.

To overcome these limitations, this report models hydrogen pipelines using the Calliope energy system modeling software with the objective of determining the necessary capacity and distribution of a hydrogen grid in Europe under a fully renewable scenario. Modeling was conducted with a spatial resolution of 35 nodes and a temporal resolution of 2 hours over a full year, using the 2018 weather data. The software uses a linear optimization method to determine the optimal configuration of the hydrogen network.

This study formulates several allocation scenarios for electrolysis capacity to examine the capacity and spatial distribution of an optimal hydrogen network under different conditions. It is found that an energy system with hydrogen hubs requires the development of extensive new pipeline infrastructure, while a system with a more balanced distribution of electrolysis across Europe requires less pipeline capacity and relies mostly on repurposed infrastructure. The estimated capacity of the network ranges from 135 to 244 TWkm. This is 40% to 70% lower than what is estimated in the European Hydrogen Backbone (EHB) vision.

In the scenario with hydrogen hubs, the study identifies four hydrogen corridors that align with the vision presented in the EHB report, with Britain, Ireland, Denmark, and Portugal as key hydrogen producers. Furthermore, the analysis highlights the significant role of salt caverns as the predominant storage technology for hydrogen, despite uncertainties surrounding their capacity estimates. The optimal storage capacity in salt caverns ranges from 42 to 178 TWh when accounting for cost and weather uncertainty.

The analysis initially considered a self-sufficient energy system, but the sensitivity to international imports was also considered. To analyze this aspect, hydrogen imports from four North African countries were included. The findings revealed that international imports play a relevant role in shaping the optimal configuration of the hydrogen network. Imports increase the required investment in infrastructure but also reduce hydrogen storage capacity and its associated uncertainty. Changes in the network configuration result in a 6% reduction in total system costs due to decreased renewable energy capacity and reliance on external hydrogen supply.

Overall, this study emphasizes the need for accurate electrolysis allocation estimation, alignment with international import planning, and efficient utilization of storage technologies in the development of hydrogen infrastructures. The findings contribute to informed decision-making and the creation of sustainable hydrogen networks that integrate effectively with renewable energy systems.