Uniper Energy Storage intends to develop salt caverns for the large-volume storage of H₂ in Northwest Germany. The initially envisaged storage capacity will be 250 GWhr to 600 GWhr, which should be available to the market before the end of 2030. To this end, existing sites and potential new sites along the planned H₂ core network are currently being analyzed in detail.

"Investments in the development of H₂ storage facilities require a regulatory and funding framework in order to achieve workable business models," said Uniper’s COO, Holger Kreetz. "By planning the development of H₂ storage facilities in the order of up to 600 GWhr by 2030, we as Uniper are making advanced investments. Whether and how the storage projects can be realized will depend largely on the framework conditions and economic viability. However, we have concrete proposals that ensure a balance between the necessary hedging of investment risks and a competitive market model on the one hand, and security of supply through storage on the other. The principles of contracts for difference should be applied to achieve the aims in a cost-efficient and effective manner.”

"In future, we want to play an even greater role in accelerating the energy transition in Europe while ensuring security of supply," said Doug Waters, Managing Director of Uniper Energy Storage. "We have a total of more than 80 TWhr of underground gas storage capacity for natural gas in Germany, Austria and the UK. This makes Uniper one of the largest storage operators in Europe. As part of the H₂ ramp-up, we want to repurpose some of our storage capacities and build new storage facilities. This will enable us to store renewable energy in the form of H₂ for industries that are difficult to electrify and potentially later on for long duration energy storage, allowing for better management of volatile renewable energies."

H₂ as a chemical and energy vector could play a decisive role in the energy transition. However, the planned stable and reliable supply of H₂ to the market with fluctuating production from 2030 will only be possible through the construction and operation of large-volume H₂ storage facilities. The transformation of the energy system requires existing underground facilities to be quickly converted to meet demand and new facilities to be built. At the same time, natural gas storage facilities must continue to maintain security of supply over the coming years.

The H₂ storage projects H₂ Pilot Cavern (HPC) in Krummhörn and HyStorage in Bierwang are already part of the implementation of Uniper's "Greener Gases" strategy and serve to prepare commercial storage projects.

The HPC Krummhörn pilot project will deliver valuable results for the realization of commercial H₂ storage systems by 2025. The Krummhörn site will then be further developed commercially in order to make a storage capacity of 250 GWhr available to the market in a first step. The commissioning of the first commercial H₂ storage facility in Krummhörn is planned for the third quarter of 2029. Over the next five years, an additional investment volume of around €200 MM will be available for the construction of the above-ground and adaptation of the underground facilities. Also, there will be the option to expand the site to further increase storage capacities after 2030.

Uniper plans to provide additional working gas storage capacities for H₂ by developing existing and new sites in Lower Saxony and North Rhine-Westphalia. H₂ storage facilities with a total capacity of up to 600 GWhr are intended to be built and put into operation by the end of 2030.

In order to better forecast the demand for the required H₂ storage capacities, Uniper Energy Storage will carry out a comprehensive market consultation until the end of March 2024. The results will serve as a further basis for the concrete expansion plans for H₂ storage sites and for the demand-driven provision of H₂ storage products in the future.

In comparison to other methods for large-scale storage of H₂, the storage of pure H₂ in cavern storage facilities has already reached industrial maturity. Cavern storage systems can compensate for short-, mid- and long-term fluctuations in production and demand, and are very efficient due to their rapid injection and withdrawal capabilities and provide required security of supply. Porous rock storage facilities, mainly found in southern Germany, offer further potential for seasonal storage of large volumes with high injection and withdrawal rates.

Uniper Energy Storage is conducting the HyStorage research project as part of consortium which includes OGE, RAG Austria, SEFE Securing Energy for Europe and NAFTA as well as other interdisciplinary partners from industry and science. It aims to investigate the influence of H₂ on porous rock formations in order to determine the suitability and integrity of pore storage systems for storing H₂. In general, however, porous rock storage facilities require individual consideration to determine their suitability for storing H₂ due to their different characteristics.