Underground storage of hydrogen – a business opportunity for valve manufacturers?

Uniper natural gas storage facility in Epe (Source: Uniper Energy Storage)

On April 24, Europe's largest gas storage operator Uniper Energy Storage announced the results of a two-month market survey on hydrogen. The result: the demand for hydrogen storage capacity is likely to increase enormously over the next few years. What does this mean for the valve manufacturer? Where can their expertise be used in the construction of H2 storage systems, and which ones are available? Find out more in today's special article.

The market consultation conducted by Uniper shows how relevant the topic of hydrogen storage is for many stakeholders: In addition to energy suppliers, power plant operators, hydrogen producers, industrial hydrogen consumers and gas traders were also involved in the survey. Even in the first phase of the hydrogen ramp-up, which is expected to begin in 2029, the expected demand for storage capacities is very high.

(Source: GIE, INES)

The country needs new storage facilities

The results coincide with those of other studies. For example, a current analysis by the Gas Infrastructure Europe (GIE) association shows that around 45 TWh of hydrogen storage capacity will be required across the EU by 2030 and around 300 TWh by 2050. By way of comparison, projects are currently only being planned for around 9 TWh by 2030 and 21.5 TWh by 2050 - the actual planned storage volume is therefore around three and 15 times lower than the expected demand.

As a result, huge underground gas storage facilities will have to be built or upgraded for the storage of hydrogen throughout Europe in the coming years. As Germany has the best geological conditions for gas storage, the market for conversions and new construction is likely to be particularly large in this country. To understand what this means, it is worth taking a look at the two most important types of storage facility.

Comparison of the most important storage types (source: INES)

Cavern or holeroom storage: structure and function

Cavern storage facilities are artificial cavities that are created in underground salt domes. They are created in two stages. The first is the drilling of the cavity several hundred meters below the earth's surface - the deepest cavern storage facilities in Germany can be up to 2.5 km deep. The size of the caverns is also considerable: they can be up to 100 meters in diameter and between 50 and 500 meters high.

The second step is leaching. This involves removing the salt present in the excavated cavities by dissolving it in injected water and then pumping it to the surface. What remains are cylindrical cavities known as “caverns”. Due to the mineral properties of salt and the thickness of the salt domes, they provide a natural seal for gases so that additional lining of the cavern wall is not necessary. The cavern storage facility is therefore a sealed, underground cavity into which the gas can be poured like liquid in a bottle.

Surface facility at the Krummhörn storage site (Source: Uniper Energy Storage)

Cavern storage for hydrogen

The advantage of cavern storage facilities is that gas can be injected and withdrawn quickly and flexibly. This makes them ideal for green hydrogen: The intensity of wind and solar energy is subject to weather-related fluctuations, which means that the production of green hydrogen also fluctuates. However, industrial hydrogen users in particular require a constant flow of hydrogen. Strategically located salt cavern storage facilities therefore fulfill an important function: if hydrogen surpluses are produced, they can be easily fed into the system. If there are then delays in production due to the weather, the hydrogen can be stored at short notice and made available to users (ideally via pipeline).

Converting an existing cavern storage facility to hydrogen opens up numerous opportunities for manufacturers of pumps, valves, diaphragms, taps and so on whose products are H2-ready. The reason: all components of the system, both underground and above ground, must be hydrogen-ready. The conversion of an existing cavern storage facility therefore takes up to five years on average, as replacing all components is almost as costly as building a new facility.

The construction of a new cavern storage facility can take up to ten years. Extensive geological preparatory work must first be carried out, numerous official approvals obtained and suitable locations for the above-ground facility found before the initial drilling can take place.

At the presentation of the first interim results of HyStorage in March 2024: er Kreetz (COO Uniper), Hubert Aiwanger, Christian Kosack (Uniper Energy Storage) (from left to right) (Source: Uniper Energy Storage)

Example Krummhörn

Storage operator Uniper Energy Storage is currently building a new hydrogen cavern storage facility in Krummhörn, Lower Saxony. The “Hydrogen Pilot Cavern - HPC Krummhörn” project is located near Wilhelmshaven, where several electrolysis projects are planned and where large quantities of hydrogen in the form of ammonia could be landed in the future.

Furthermore, the existing natural gas caverns near Krummhörn are currently not in operation, which would interfere with existing natural gas storage operations. Uniper is using an existing well for the project, from which the pilot cavern is being developed. Initially, the facility is still relatively small in size. The gas trader's aim is to show how quickly a new cavern storage facility can be put into operation - this is what interests the first hydrogen customers the most.

Since mid-January, Uniper engineers have been working on the excavation of the cavern, which should be completed in the summer. The opening of the storage facility for a realistic trial operation is planned for August. The site will then be further developed commercially in order to provide the market with a storage capacity of 250 GWh as a first step.

Pore reservoirs

Pore reservoirs, also known as “rock pore reservoirs”, “reservoir storage facilities” or “reservoirs in porous rock formations”, are former natural gas reservoirs in limestone and sandstone layers. Natural gas accumulated here over millions of years and was pumped to the surface by humans at some point. After the end of this extraction, these natural gas reservoirs can be converted into underground storage facilities. Porous rock, which previously contained natural gas, absorbs the stored gas like a sponge. The ceiling of the pore storage facility consists of a closed layer of rock that prevents gas from escaping.

While pore storage facilities play an important role in the long-term storage of natural gas, their use for hydrogen has hardly been investigated to date. The reason for this is that injection and long-term storage are much more challenging than with salt caverns. This is because hydrogen is very reactive towards organic material and some minerals. This means that it can react with surrounding materials and change chemically during storage in porous rock.

The biggest difference between cavern and pore storage is therefore that with an artificially created salt cavern, it can be assumed that the stored hydrogen will come out again. With pore storage, on the other hand, it is unclear how pure the released hydrogen is. Research into this is ongoing.

The first Hartmann wellhead for hydrogen test phase 1 was recently installed in the Netherlands. The operator Gasunie is responsible for the development of the national hydrogen infrastructure there. (source Hartmann Valves GmbH)

HyStorage: Uniper storage facility in Bierwang

In the HyStorage project, Uniper is investigating the storage of hydrogen in pore storage facilities in Unterreit in southern Bavaria. In mid-March, the gas storage operator presented the interim results of its research project on the suitability of pore storage facilities for hydrogen storage at the Bierwang storage station.

The engineers in the project group - in addition to Uniper's Specher subsidiary Uniper Energy Storage, OGE, RAG Austria, SEFE and Nafta Speicher are also involved - are not yet injecting the hydrogen here in its pure form, but as an admixture to conventional natural gas. They want to increase the proportion of hydrogen from 5 to 10 to 25 % by 2025. After standing for several months, the gas mixture is stored and analyzed again.

The team completed the first operating phase with a 5 % admixture at the end of January. The aim was to find out whether the technical facilities are fundamentally suitable for hydrogen storage. The data has been intensively evaluated in recent weeks.

The result: during the seven-day extraction phase, almost 90% of the previously injected hydrogen was recovered. The performance of the storage facility had previously remained constant with a “very homogeneous hydrogen distribution” within the storage facility. Furthermore, the tested materials showed no influence of hydrogen corrosion, according to Uniper in a press release. In the coming project phases, the partners want to investigate whether the initial results also apply to higher hydrogen concentrations. Depending on the results of the further evaluation, the second operating phase is set to begin this year.

“The initial preliminary results are generally optimistic,” commented Doug Waters, Managing Director of Uniper Energy Storage. However, it is still too early for a final classification of the porous rock formations in southern Germany for pure hydrogen storage. In general, the underground storage facilities in Bavaria are “of great importance for the security of natural gas supply in the coming years and, in the long term, for the transition to seasonal hydrogen storage” due to their large volumes and high injection and withdrawal rates, said Waters.

Opportunity for hydrogen valves made in Germany?

German industrial valve manufacturers now have the opportunity to expand their business in the field of underground hydrogen storage. With the growing importance of hydrogen as a component of the energy transition, the demand for efficient storage options is also increasing. This is where underground hydrogen storage facilities come into play. The construction and conversion of salt cavern storage facilities in particular will require large numbers of hydrogen-compatible valves in the short term, but projects such as Uniper's HyStorage indicate that pore storage facilities also have a promising market.

Industrial valve manufacturers have the expertise and know-how to develop high-quality fittings and valves that are especially suitable for use in gas storage. Examples can be found at companies such as Vexve, which emerged from the merger of Armatury and ZMK-Technologies, and HEROSE from Bad Oldesloe, which develops solutions for cryogenic gas storage, among other things. Components from these manufacturers are already playing a key role in the safe and efficient storage of hydrogen.

The task now is to develop underground storage facilities. Caverns and other underground structures could prove to be a veritable Mecca for valve manufacturing: By developing specialized valves that meet the demanding requirements of these environments, industrial valve manufacturers can strengthen their market position and benefit from the growing need for hydrogen storage solutions. Numerous studies confirm that demand in this field will increase. Overall, this growing demand for hydrogen storage solutions and the existing expertise of German industrial valve manufacturers therefore offer prospects for the expansion of traditional business in a future-proof area - because reliably stored hydrogen is not just a flash in the pan.

You can find out more about hydrogen in the industrial sectors of fittings and valves at VALVE WORLD EXPO from December 3 to 5, 2024 in Düsseldorf. The latest industry and product information can be found on the internet portal at www.valveworldexpo.de.

Further information and sources

https://www.uniper.energy/de/ueber-uniper/unternehmensportfolio/energiespeicherung?gad_source=1&gclid=EAIaIQobChMIkNT6oP7chQMVCpRoCR3RbA95EAAYASAAEgLQ-fD_BwE

https://energien-speichern.de/

https://h2-news.de/thema/speichersysteme/

https://www.vexve.com/de/vexve-armatury