Expansion Project RWE Epe-Hydrogen Storage

The current transformation of the European energy market requires sufficient storage capacities for the emerging use of hydrogen as an energy carrier. The Gronau-Epe site is also suitable as a hydrogen storage location due to its connection to the hydrogen core network and its proximity to the Netherlands and the hydrogen system being developed there in conjunction with the optimal geological conditions for gas storage.

RWE Gas Storage West continues to lead the acceleration of the European hydrogen market.

Therefore, RGSW is expanding its plans to the first hydrogen storage facility currently under construction at the Kottiger Hook site in the Gronau-Epe storage field. In addition to the first construction phase currently underway, additional underground and above-ground facilities are planned for the storage of hydrogen gas.

The facilities will be constructed in such a way that the second commercial construction phase will enable the use of additional caverns for the storage of approx. 80 million m3 of hydrogen with a gross volume of 45 million m3 of usable hydrogen by customers.

Additional capacities of approx. 45 million m3 of hydrogen with a volume of 25 million m3 of hydrogen that can be used by customers are available for a later expansion as part of a further commercial expansion.

An investment decision beyond the first construction phase is still pending. The current planning and approval steps serve medium-term expansion plans.

For the second commercial construction phase - in addition to the existing planning approval for the expansion of the above-ground facilities in accordance with approval construction phase 2 - it is planned to convert and fill two caverns previously used for the storage of natural gas for hydrogen storage and to convert an existing field pipeline to hydrogen operation as part of the third approval construction phase.

For later expansions as part of further commercial construction stages, part of the planning approval procedure that was recently launched is

• ... to expand the existing above-ground facility at Kottiger Hook on an additional, neighboring site as part of the fourth approval stage to include additional injection and withdrawal lines for hydrogen, ancillary facilities required for operation and a further grid connection, and also to convert and fill a cavern previously used for storing natural gas for hydrogen storage
• ... to expand the above-ground facilities on the expansion site by adding further withdrawal lines for hydrogen and the necessary ancillary facilities for operation as part of the fifth approval stage

On 18 January 2024, RWE Gas Storage West received the planning approval for the expansion of the gas storage site in Gronau-Epe to include additional plant components for hydrogen storage (5th addendum to the framework operating plan). This approval covers the creation of 2 construction stages on the existing site and the utilization of 2 caverns with hydrogen.

On 19 March 2024, RWE Gas Storage West GmbH submitted the initial documents for the approval procedure for further underground and above-ground hydrogen storage facilities to the Arnsberg district government in the form of a planning notification and requested that the authority carry out a general preliminary assessment in accordance with the UVPG. On 17 July 2024, RWE Gas Storage West GmbH updated the planning notification and requested that an environmental impact assessment (EIA) be carried out voluntarily. The current application comprises the authorisation construction stages 3-5 described above.

RWE Gas Storage West GmbH informed the public about the start of the authorisation procedure in a press release, which was published by the local print media.

The Committee for Mobility, Environment and Climate Protection of the City of Gronau was also informed about the future plans at its June meeting as part of a project presentation on the ongoing construction project.

The second commercial construction phase of the hydrogen sub-plant has been on the PCI (Projects of Common Interest) list since April 2024.

RWE Gas Storage West GmbH plans to reapply for funding for the construction of the second commercial construction phase in 2025.

With regard to the requirements resulting from Regulation (EU) 2022/869 of the European Parliament and of the Council of 30 May 2022 on guidelines for trans-European energy infrastructure, hereinafter referred to as the TEN-E Regulation, the competent national authority within the meaning of Article 8(1) of the TEN-E Regulation is the Arnsberg district government. Responsibility was transferred from the Federal Network Agency (BNetzA), the original competent national authority, to the Arnsberg district government, which approved this transfer on 2 April 2025.

A final investment decision for the realisation of a further H2 storage project has not yet been made and is dependent on the receipt of funding and sufficient and secure demand for storage capacities.