EUH2STARS: European Underground Hydrogen Storage Reference System

THE EUH2STARS is an ambitious, industry-driven flagship project supported by the Clean Hydrogen Partnership (via the 2023 call HORIZON-JTI-CLEANH2-2023-02-1 – Large-Scale Demonstration of Underground Hydrogen Storage programme).

The project consortium, comprising of natural gas storage operators, technology providers, utility, research- and governmental organisations, is entrusted by the European Commission to demonstrate a competitive, complete and qualified underground hydrogen storage (UHS) in depleted porous natural gas reservoirs at technical readiness level (TRL) 8 by the end of the decade. Furthermore, EUH2STARS is a European flagship project for the conversion of existing underground natural gas into hydrogen storages and will pave the way for their integration into the future European hydrogen infrastructure. This will be demonstrated via several replication sites which are an integral part of the EUH2STARS project.  

As one of Europe’s biggest natural gas storage operator’s, RAG Austria AG is in the unique position to contribute an already existing UHS pilot facility, developed to TRL 6 within the Underground Sun Storage 2030 project, to the EUH2STARS project. A broad range of experience gained within the implementation of USS 2030 shall be processed to develop and define overarching rules and recommendations for hydrogen underground storage across Europe complemented with project experiences from consortium partner’s research activities (e.g. HyUSPRe, Aquamarine, Undergy, H2 Moonshot). 

Based on the broad range of the consortium’s experiences in underground hydrogen storage, EUH2STARS aims to deliver following key-results: 

• Provide guidelines to manage successful all environmental, safety, legal and (future) regulatory, societal and market-related aspects to ensure a successful implementation of an UHS facility in Europe including stakeholder engagement strategy. 

• An interactive stakeholder involvement process (workshops, webinars, site visits) to maximise public acceptance, transparency and visibility. 

• Generate a generic framework on the topic of Health, Safety, Environment and Quality (HSEQ) including a facility site monitoring plan to ensure UHS at an ALARP (as low as reasonably practicable) risk level when operating the RAG demonstrator / replicators and future commercial storage sites. 

• Demonstrate the storage of 100 percent hydrogen in depleted, porous reservoirs by operating four seasonal storage cycles at RAG’s demonstrator and two storage cycles at HGS’s replicator site. Each storage cycle considers different operational characteristics to demonstrate marked-driven underground hydrogen storage operation at the end of the project.  

• Develop a beyond state-of-the-art hydrogen purification system and integrate it into the demonstrator’s withdrawal process. Demonstrate the successful separation of impurities (mainly natural gas) in the reservoir from hydrogen during withdrawal cycles to achieve standardised hydrogen purification levels (e.g. hydrogen grade A or better). 

• Achieve a relevant green hydrogen certification for the demonstrator’s power to hydrogen electrolysis and engage actively in green hydrogen certificate trading.  

• Show transformation pathways to replicate demonstrator findings in full-scale commercial settings at existing underground natural gas storage facilities and new to be developed underground hydrogen storage sites in depleted natural gas reservoirs in Europe by providing subsurface design and surface facilities engineering. The replicator underground hydrogen storage sites are located in Austria (RAG), The Netherlands (SHELL), Hungary (HGS), and Spain (TES) and include a comprehensive CAPEX assessment with potential investment decision throughout project duration. 

• Best practice examples on how to integrate underground hydrogen storage facilities into regional, national and European energy infrastructure and markets by showcasing specific use cases in AT, HU, NL and ES including the integration into the European Hydrogen Backbone. 

• To include 3rd party opinions and knowledge, an external expert advisory board will monitor the project and give stakeholder related recommendations to maximise the project’s replication potential and exploitation of the demonstrator and replicators results.