The transformation from a gas to a hydrogen network

Green hydrogen is considered a key element of the energy transition in Germany. Many large energy consumers are to be operated with green hydrogen in the future, replacing the climate-damaging fossil fuels oil, gas and coal.

To this end, Germany has adopted a plan, the ‘National Hydrogen Strategy’. It defines how much hydrogen is to be produced in this country and what the infrastructure should look like. Since it seems impossible to produce all of Germany's hydrogen needs domestically, the federal government expects that 50 to 70 per cent of the hydrogen will have to be imported by 2030. So much for the plan.

But now, question marks are growing over when the climate-neutral energy source will arrive for many projects. There are increasing reports of projects being significantly delayed or cancelled. For example, Denmark recently announced that the start of a hydrogen pipeline to Germany would be postponed from 2028 to 2031. Several activities are said to be ‘more extensive and time-consuming than originally assumed’. A project planned by Norway also made a U-turn at the end of September: the hydrogen pipeline to Germany, which was supposed to transport so-called blue hydrogen as an interim solution, will not be built because the demand for blue hydrogen has not been clarified.

On the other hand, there are also many positive signals. For example, the contract for a 100 MW electrolyser in Hamburg was awarded in September.

And in mid-October, the Minister for Economic Affairs, Robert Habeck, belatedly presented the plans for the German hydrogen core network. A total of around 9,000 kilometres of pipelines are planned. For 60 percent of this, existing gas pipelines are to be used and converted to hydrogen; the rest will have to be newly constructed. The network will also include 13 hubs at the German borders for imports and is to be completed by 2032. The costs are estimated at almost 19 billion euros.

However, there is still a great deal of uncertainty, which seems to be mainly due to the lack of regulatory requirements and the uncertain availability.

Regardless of these developments, there is broad consensus that large quantities of green hydrogen will be needed for back-up power plants during periods of low sunshine and wind, for many industrial processes that cannot be meaningfully electrified as things stand, and for shipping and aviation (possibly with hydrogen derivatives).

Recommended approach for today's gas network operators

Hydrogen has different physical and chemical properties than natural gas. It is lighter, more diffusible and more flammable. In addition, hydrogen tends to make materials such as steel or cast iron brittle, especially at high pressure. This effect can cause cracks or fractures in the pipes. Gas network operators must therefore first ensure that the materials used in their network meet the requirements of hydrogen transport.

Gas network operators who also have a long-term interest in operating their infrastructure should first check/clarify the following points:

• a) Is the planned hydrogen core network close by, so that grid-bound hydrogen will be available at all in the medium to long term?
• b) Are there any network customers or customer groups of their own who are highly likely to need hydrogen on a larger scale in the future, especially if there is no economically more sensible alternative in the long term?

If the answer to both questions is ‘yes’, a medium and long-term strategy should be developed that addresses the following points if possible:

• a) Objective: Clear targets for the hydrogen share and the time frame for the transformation should be set.
• b) Roadmap: A roadmap should define the gradual conversion from natural gas to hydrogen.
• c) Consider market development: Gas network operators should align themselves with national and European hydrogen strategies and map this using scenarios.

Subsequently, the strategy must be ‘operationalised’: as already mentioned, the gas grid must be tested for hydrogen suitability. To do this, a technical evaluation of the existing infrastructure is necessary with regard to material properties, seals and fittings in order to identify possible weak points.

A moderate approach is useful here, since it is not to be expected in the medium to long term that the entire current gas grid will be converted to hydrogen operation.

The following should be inspected as a matter of priority:

• 1) High-pressure lines: HP lines are to be inspected more critically than MP or LP lines, as they will transport the majority of the hydrogen in the grid. The pressure of the hydrogen can increase the material stress and the risk of leaks or failures is higher in these grid areas. Furthermore, it is likely that the prospective customers requiring hydrogen are already connected to the high-pressure grid.
• 2) Older network sections and sections with high corrosion risk: older pipelines still made of materials such as cast iron or low-quality steels should be inspected as a matter of priority. These materials are particularly susceptible to hydrogen embrittlement and leaks. In addition, areas of the network that are already known to have corrosion problems or where cathodic corrosion protection is used should be prioritised for inspection to identify any material weaknesses. Metallic pipes are particularly susceptible if they are old and have been installed in environments with high humidity or salty soil.
• 3) Compressor stations and regulating stations: Compressor, regulating and pressure-reducing stations contain many mechanical components and seals that can be prone to leakage or material failure.
• 4) Sections with many connections and transition points: Transition points such as connections, flanges and valves often represent weak points in the tightness of a gas network. Since hydrogen has smaller molecules than natural gas, it can escape more easily through these connections.

It is therefore not absolutely necessary to examine the entire gas network if such a risk-based and prioritised approach is applied.

Procedure for a hydrogen suitability assessment

To check the suitability of network components, information is needed on the material, function and condition of these assets.

This data is usually available at gas network operators, but it is often stored in different systems and formats. In addition to IT systems, many gas network operators also have analogue archives with relevant documents such as material procurement, maintenance reports, house connection maps, operating and acceptance protocols.

The first step towards a hydrogen suitability study for a gas network operator is thus to provide this data across system and format boundaries.

Together with Open Grid Europe GmbH (OGE), adesso has developed a methodology and tools for the automated extraction and processing of the required data from IT systems and document archives for the hydrogen suitability study of gas networks.

Initially, a so-called maturity check can provide an initial objective indication of the quality and quantity of the existing data. By using AI and proven OCR tools, the effort required can be reduced and the quality of the data provision can be significantly improved compared to previous solutions. The solution implemented by adesso combines the advantages of both technologies.

Depending on the scope of the documents, automated data capture can save up to several person-years compared to manual data capture.

Our approach includes clustering and sorting the digitised documents in the first step. Only clusters identified as relevant are processed by the AI-supported capture, and their data is captured in a structured format, thus saving costs and reducing processing time.

The collected data can be used to carry out suitability tests for individual components and pipe sections. Our project partner OGE is available for this. However, databases such as verifHy from the DVGW can also be used.

How AI supports the hydrogen suitability test

In addition to this use case of automated data collection, AI can provide technical support to gas network operators at various levels. Some of the possible applications adesso is working on are presented below:

Standardising data formats

Data is often stored in different formats and systems (Excel spreadsheets, databases, PDF reports). An AI can convert the information into a standardised format that is easily accessible and analysable.

Identifying missing or incomplete data

By analysing existing data sets, AI can identify gaps, such as missing material information, incomplete historical maintenance reports or inconsistent information on pipe sections. Reports can be automatically generated that specifically highlight these gaps.

Predicting data gaps

Machine learning can be used to fill in the gaps in these incompletely recorded network sections. AI can use machine learning and statistical models to make predictions about the missing information. For example, it can draw conclusions and probabilities about the material composition or the condition of pipes from comparable network sections, material and procurement records, and construction documentation.

Intelligent risk and prioritisation recommendations

With the help of an AI, it is possible to create a risk analysis from the collected data such as material information, age of the pipes, maintenance history and environmental conditions. It helps network operators to identify vulnerable areas in the network.

On the basis of this information and evaluations, network operators can plan a prioritisation for the exposure of pipe sections.

Outlook: adjacent use cases / synergies

The data obtained or processed from the hydrogen suitability study can also be used for other applications by gas network operators. This means that further use cases can be served with little or no additional effort. Some examples are listed below that can also be processed completely independently of a hydrogen suitability study:

Generation of a digital twin of the network

Network operators can use digital twins of their gas networks to serve use cases such as heat planning or decarbonisation strategies well and calculate and map scenarios relatively easily with them.

Simulation support

By integrating data on material compatibility and operating history, gas network operators can perform simulations and calculations for their operational and strategic network planning more easily and with greater precision.

Predictive models for maintenance measures:

With the help of historical maintenance data and operational information, AI can create a more accurate predictive model of when and where network components are likely to require replacement or maintenance. This predictive maintenance helps to avoid outages and optimise the operation of the gas network.

Company chatbot

Last but not least, a chatbot trained with the data can help to provide employees with quick access to this data through simple interaction via text input. This way, information can be retrieved quickly and displayed as a report or statistic.

Example prompt: ‘Give me all the pipes from the year of construction 1970-1980 that have already been uncovered, sorted by material, street sections and the reason for uncovering.’

Conclusion

Gas network operators should urgently consider their future strategy. Please feel free to contact us if you want to prepare your network data and analyse your network for hydrogen compatibility.

Would you like to learn more about exciting topics from the adesso world? Then take a look at our previously published blog posts.

This is how we support you

Hydrogen plays a central role in the energy transition – and adesso offers innovative solutions to fully exploit this potential. With a holistic approach, adesso supports you in developing and implementing efficient hydrogen technologies, from production to integration into existing energy systems.

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We also support you in making optimal use of your data and successfully implementing data-driven strategies – from data analysis and infrastructure to utilisation for business added value.

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