HYBRIT's pilot project for H₂ gas storage has now been completed and reported to the Swedish Energy Agency. The results show that it is technically possible to store fossil-free H₂ gas for producing fossil-free iron and steel on an industrial scale. This can also reduce the variable operating costs of H₂ production by up to 40%.

The HYBRIT initiative was launched in 2016 by owners SSAB, LKAB and Vattenfall with the aim of developing the world's first fossil-free, ore-based iron- and steelmaking using fossil-free electricity and H₂ gas. The project for the production of fossil-free sponge iron for steel production (DR pilot) is now being followed up with the results of the pilot for fossil-free H₂ gas production and storage.

The project has successfully designed and constructed a 100 m³ H₂ storage facility based on steel-lined rock cavern technology in Svartöberget adjacent to the DR pilot for sponge iron production in Luleå, Sweden. The tests now completed show that the technology works to support a large-scale H₂ user, and that savings of about 25%─40% of the variable operating costs of H₂ gas production could be reached. The pilot storage facility has undergone accelerated mechanical testing equivalent to approximately 50 years of operation, and the safety, functionality and performance of the facility have been successfully demonstrated.

“The pilot project has been highly successful and has given us the results we hoped for. We have shown that it is possible to use this technology to increase the flexibility of the electricity system and that it is a safe design that lasts overtime. H₂ gas storage is an important piece of the puzzle to electrify industrial processes while increasing the amount of weather-dependent power. With the results and experiences gained from the pilot project, the technology is now ready to be scaled up,” said Mikael Nordlander, Director, Industry Decarbonization at Vattenfall's Industrial Partnerships.

Future fossil-free industrial processes using H₂ gas from fossil-free electricity instead of fossil fuels will mean that industry will be more dependent on the electricity system. In this case, it is crucial to secure the supply of H₂. The purpose of a H₂ storage facility is primarily to be able to adjust H₂ production to electricity market fluctuations. H₂ gas production costs are optimized by producing and storing surplus H₂ gas when electricity prices are low and reducing production and using the stored H₂ gas when prices are high.

“H₂ is an important part of LKAB's future strategy and journey towards carbon dioxide-free products and processes. We have yet to make any decisions on H₂ gas storage, but the successful results from the pilot give us good conditions when we review the needs and opportunities for storage in conjunction with our planned sponge iron production facilities,” said Jenny Greberg, Vice President of Technology at LKAB.

“The results from the HYBRIT pilot project show that large-scale storage of fossil-free H₂ is technically possible and economically beneficial. With these innovative technologies, we can build strong fossil-free value chains with the potential of drastically reducing the climate footprint of the iron and steel industry,” said Martin Pei, CTO at SSAB.

The steel industry currently accounts for around 7% of global carbon dioxide emissions. The HYBRIT technology will enable SSAB to reduce Sweden’s and Finland’s carbon dioxide emissions by 10% and 7% respectively. The Swedish Energy Agency has co-financed 22% of the H₂ storage project, with the remainder having been financed by the owner companies.

“It feels great that HYBRIT now summarizes another successful pilot program, this time for underground H₂ gas storage. HYBRIT has focused on building competence and creating important experiences for an industrial application of the technology. The pilot facility tests in Luleå have shown that H₂ gas storage with LRC technology works. And with the knowledge and experience generated by the team, it is now possible to take the next step,” said Gunilla Hyllander, General Manager at Hybrit Development AB.

Facts:

• The pilot storage facility has been operating intermittently with H₂ gas since 2022, in campaigns of 3 to 6 weeks. Around 3,800 hours of operation combined with H₂ gas production and storage with 94% availability have been reached.
• The safety, function and performance of the facility have been successfully demonstrated.
• The choice of the material to seal the rock cavity has been one of the main issues in the project. The steel material chosen has shown resistance to H₂. No leakage of H₂ gas from the sealing layer of the storage facility (steel-lined rock cavern) has been detected.
• The pilot storage facility has undergone accelerated mechanical tests equivalent to about 50 years of operation.
• The project proves that the technology is ready for industrialization. The tests have shown that H₂ gas storage works in the HYBRIT value chain to support a large-scale H₂ user, in this case a DRI plant in Luleå.
• Optimized operation of the storage facility has been done in real time both against the spot price and intraday market. Savings of 26%─31% of variable operating costs have been demonstrated in practice. Simulations of future scenarios for the Swedish electricity market indicate that savings of about 25%─40% of variable operating costs could probably be reached when the first commercial plants are commissioned.
• HYBRIT has extended the pilot project for storage of fossil-free H₂ gas until 2026 to be able to carry out additional tests to further improve the conditions for enabling the design of commercial H₂ storage.