Report: Cavern and Subsurface Storage
Underground hydrogen storage (UHS) plays a pivotal role in enabling the large-scale integration of green hydrogen and advancing the transition toward zero-emission energy systems. Among the various UHS technologies, salt caverns emerge as a particularly attractive option due to their technical reliability, operational safety, and relatively low cost. As hydrogen demand grows across sectors such as industry, heating, and transportation, a robust storage infrastructure is essential to address the spatial and temporal mismatches between production and consumption.
This study explores the optimal design of a hydrogen storage network in the Northern Netherlands (NN) by linking potential UHS sites with projected hydrogen demand for the year 2050. A facility location problem (FLP) model is developed and applied to three demand scenarios—low, medium, and high—to determine cost-optimal configurations that minimise transport and storage costs.
The model results indicate that under a low-demand scenario, only one storage site is utilised, whereas up to nine out of ten candidate sites are selected under high-demand conditions. However, the available salt-cavern capacity proves inadequate in medium- and high-demand scenarios, underscoring the need for complementary storage solutions such as depleted gas fields or above-ground tanks.
These findings highlight the importance of scenario-based planning and accurate demand forecasting in guiding hydrogen infrastructure investments. Additionally, qualitative insights from five expert interviews inform key model assumptions and scenario development. Aligning UHS strategically with spatially distributed demand centres enhances system flexibility and cost-effectiveness, offering valuable guidance for regional hydrogen-network planning.
From storage potential to regional planning
The Northern Netherlands has an estimated theoretical salt-cavern storage potential of approximately 43.4 TWh, based on around 321 identified caverns across ten locations. However, constraints such as limited surface space, the risk of land subsidence, the availability of water for cavern development and requirements for brine disposal reduce the realistically developable capacity to around 15 TWh by 2050.
This difference between theoretical and practical capacity is an important consideration for future infrastructure planning. The report therefore highlights the need to examine complementary options, including depleted gas fields and cross-border storage capacity in Germany. Its recommendations include phased investment incentives, harmonised cross-border regulation and the alignment of regional storage targets with verified demand from industry and mobility.
From underground storage to an integrated hydrogen system
HEAVENN aims to demonstrate an integrated hydrogen value chain from production to distribution and end use. The storage study contributes to this ambition by connecting geological potential with the expected spatial distribution of hydrogen demand. It provides decision-support insights for determining where underground storage facilities could be developed and how the required network may change under different demand scenarios.
These findings are particularly relevant to HEAVENN and other Hydrogen Valley initiatives, where infrastructure investments must account for both subsurface constraints and evolving demand. By bringing together geological resources, spatial optimisation, projected demand and stakeholder knowledge, the study supports the development of scalable and resilient regional hydrogen infrastructure.
The complete findings, methodology, scenarios and recommendations are available in HEAVENN Deliverable 6.5, Report of Cavern and Subsurface Storage.
The research behind the report was also published as the peer-reviewed article Structuring hydrogen storage networks: Matching geological capacity with future demand in the Northern Netherlands in the scientific journal International Journal of Hydrogen Energy.