The hydrogen core network forms the basic framework for the development of the hydrogen infrastructure in Germany. Between 2025 and 2027, around 9,700 kilometres of hydrogen pipeline should gradually come into operation across Germany. Existing natural gas pipelines will be repurposed and new hydrogen pipelines will also be built. The goal of the core network is to connect generation and consumption centres with one another. The hydrogen core network is a key infrastructure for the future, without which the decarbonisation of our energy supply and important industry sectors cannot succeed. The rapid and efficient realisation of the core network is a basic requirement for successfully ramping up the hydrogen economy market

According to the published application (see https://www.bundesnetzagentur.de/DE/Fachthemen/ElektrizitaetundGas/Wasserstoff/Kernnetz/start.html (in German only)), the core network will comprise around 9,700 kilometres, based on the scenario that has been determined. The pipelines should come into operation step by step in the period between 2025 and 2032. The feed-in and feed-out capacities of the core network are around 100 GW and 87 GW respectively. The core network application also provides for around 800 kilometres of pipeline infrastructure from natural gas distribution system operators at transport level.
The inspection and approval of the core network is within the remit of the Bundesnetzagentur as per Section 28q of the Energy Industry Act. The procedure ends with the Bundesnetzagentur’s approval of the hydrogen core network. The plans can then be fully realised.

The scenario and determined criteria underlying the core network have not changed, meaning that feed-in (100 GW) and feed-out (87 GW) capacities for the core network also remain unchanged. In the core network application from 2023 (see https://www.bundesnetzagentur.de/DE/Fachthemen/ElektrizitaetundGas/Wasserstoff/Kernnetz/start.html (in German only)), the transmission system operators have considered the results of the consultation on the informal draft application from November 2023, which were arrived at in dialogue with the Bundesnetzagentur and further potential hydrogen network operators, and have adjusted their modelling accordingly. This has resulted in the addition of certain individual pipelines and the removal of others for reasons of cost and network efficiency. The planned full network length of around 9,700 km remains virtually unchanged. At around 60%, the share of adapted pipelines remains the same as in the draft from 15 November 2023.

Developing the core network entails repurposing pipelines, i.e. converting pipelines currently used to transport natural gas to hydrogen operations, and building new pipelines, compressor stations and gas pressure reduction and metering systems (PRMSs). Around 60% of the full length of the core networks will consist of repurposed pipelines. Pipelines connecting up specific final consumers do not form part of the hydrogen core network, since the focus of the core network is on the supra-regional transport level.

The reason for the comparably “denser” pipelines in northwest Germany is the many generating sites that will arise there as part of electrolyser projects. There are also multiple locations for imports from neighbouring countries (e.g. Denmark, Norway or the Netherlands) planned in the northwest of Germany. Sufficient transport capacity must therefore be present to be able to transport the generated and imported hydrogen from the northwest to other parts of Germany where it is needed.

According to the application made by the transmission system operators, the first pipelines should already come into operation in 2025. After all, the core network includes hydrogen pipelines that are planned to come on stream between 2025 and 2032. The pipelines will enter into operation in a step-by-step manner. It is important that the security of supply of natural gas is ensured at all times – there can be no bottlenecks in the natural gas supply due to repurposing for hydrogen. Here, the measures to strengthen natural gas play a part, and they will take place in parallel.

Section 28q subsection 8 of the Energy Industry Act provides for a time-limited flexibility option. In accordance with this, the coming on stream of individual pipelines may be postponed by the Bundesnetzagentur until 2037 in the event of delays in demand for hydrogen. This can occur within the framework of regular network development planning and only applies for core network pipelines which have already been approved by the Bundesnetzagentur. The target operational year for the entire core network remains 2032. The repurposed and newly built pipelines of the core network should gradually come on stream between 2025 and 2032. The flexibility option is therefore not a postponement of the core networks, but rather offers the possibility to bring already approved pipelines on stream at a later date in isolated cases where the need for this specific pipeline will not come to fruition until a later point. The flexibility option aims to avoid potential vacancies and thus to keep network fees low, which is a core requirement for the successful ramp-up of the hydrogen market.

As part of the ongoing biannual network development planning for gas and hydrogen and in accordance with European requirements, the Energy Industry Act provides for a review to be conducted by the Federal Network Agency of all measures in the core network, with this review planned to commence after 31 December 2027. This enables demand-oriented development of the network that aligns with the market ramp-up and allows for the incorporation of current insights and market developments. Within the context of this inspection and confirmation, responsible companies (“project organisers”) will be determined for the relevant pipelines, provided this did not already occur in the application. Projects for which no company has yet been named responsible in the application document, will be conceptually developed by the TSOs in close dialogue with market participants until their final confirmation in the Network Development Plan, with a special view to spatial planning and possible pipelines routes. Market participants can find relevant contacts on the FNB Gas e.V. industry association’s website.

When a pipeline is repurposed from natural gas to hydrogen, this process entails a significant change within the meaning of the High-Pressure Gas Pipeline Ordinance due to the use of the pipeline for another medium. The repurposing is planned by the pipeline operator and submitted to the approving authority in conjunction with an expert opinion from a subject expert in accordance with the High-Pressure Gas Pipeline Ordinance. The pipeline network operator and the subject expert create a catalogue of measures listing the steps that must be undertaken for each individual pipeline (individual assessment). This catalogue is then progressively fulfilled by the network operator with supervision from the subject expert. Depending on the condition of the pipeline and the resulting catalogue of measures, this can take multiple years. As part of the repurposing process, natural gas is drained from the pipeline, e.g. using compressor stations, and further adaptation measures are then carried out in the depressurised environment. The pipeline is then flushed and filled with hydrogen in order to transition to a regular transport regime.

The hydrogen core network requires existing natural gas pipelines to be converted on a large scale – about 60% of the core network. Natural gas demand will continue to decline until 2045, in order to achieve the goal of climate neutrality. However, it must be ensured that the remaining long-distance transmission system can continue to meet the natural gas demands that continue to exist. To this end, so-called strengthening measures for natural gas are necessary in certain places. This is mostly limited to shorter sections of pipeline, sometimes under a kilometre in length (around 560 km in total).

Estimates indicate that it will take around five to eight years to build a new hydrogen pipeline. This estimate is dependent on the length of the pipeline and also on the duration and requirements of the approval process. Constructing new pipelines is also significantly more expensive and time-consuming than repurposing existing natural gas pipelines, which is why the core network will largely consist of repurposed pipelines. The Hydrogen Acceleration Act is intended to speed up and simplify relevant planning, approval and procurement procedures.

The basis for the modelling of the core network is provided by a scenario which has been established on the basis of criteria developed for this purpose. The scenario has a guiding role for the size of the core network. According to Section 28r subsection1 of the Energy Industry Act, the core network is to be a nationwide and expandable hydrogen network for supra-regional transport, accessing the major hydrogen consumption and production regions known at present in Germany. Against this background, IPCEI (Important Projects of Common European Interest) and PCI/PMI (Projects of Common/Mutual Interest) are being considered, alongside projects that serve to connect Germany to a European hydrogen network. Further criteria are also being employed, such as projects from industrial sectors where hydrogen is currently foreseen as the only option for decarbonising industrial processes (iron and steel, chemicals, refineries, glass and ceramics, among others). Regulatory Sandboxes for the Energy Transition, hydrogen storage projects and large CHP power plants (ones with over 100 MW of electrical CHP output) are also being considered in lieu of future hydrogen power plants. Additionally, sufficient connection options for production regions and electrolysers must be ensured in line with the path of expansion set out in the National Hydrogen Strategy (NHS), and a regional balance should be established.

No, the core network is only the basis and not the final stage of expansion for Germany’s hydrogen infrastructure. The second stage of the hydrogen transport network planning describes a hydrogen network with supra-regional, “wide-scale coverage”, to be determined through scenario and demand-based planning. In this regular planning process, further need for network expansion will be identified in order to achieve a hydrogen network that meets German demand and to which further hydrogen consumers, generators and storage facilities can be connected. As part of this second stage, an integrated biannual Network Development Plan for gas and hydrogen will be developed on a rolling basis and with the aid of a comprehensive consultation process. This integrated Network Development Plan is to be approved by the Bundesnetzagentur for the first time in June 2026. In this context, further sectors and industries can be considered in the network planning.

The future integration of the core network into a European hydrogen network is in line with the Federal Government’s National Hydrogen Strategy. Cooperation projects between the relevant neighbouring countries will be established and deepened along the hydrogen import corridors. Beyond this, the aim in the medium term is to establish stronger and closer cooperation with interested EU Member States that will allow a coordinated market ramp-up, set common standards, facilitate coordination, and make it possible to synchronise imports. A large proportion of the hydrogen needed in Germany will be covered by imports; according to estimates by the Federal Government including analysis of current scenarios, around 50% to 70% will already be covered by imports from abroad by 2030. Projects of common or mutual interest (PCI/PMI) are already an integral part of the hydrogen core network scenario. These are cross-border infrastructure projects that connect the energy systems of the EU Member States (and potentially beyond) with one another. Detailed explanations of the assumptions regarding the border crossing points in the hydrogen core network can be found in the annex of the core network application.

The financing for the core network should in principle fully come from the private sector. For this reason, the Federal Government has developed a financing concept together with market players that incentivises private sector investments and enables the hydrogen core network to be fully financed via network fees. The concept includes a subsidiary financial guarantee against unforeseeable development through the state and prevents the risk that high fees will jeopardise the hydrogen ramp-up during the initial years. Network fees for hydrogen consumers are also capped for this reason. As only a few users will be connected in the first years, the initial high investment costs cannot be fully passed to the users. The revenue shortfalls that accumulate in this first phase will be offset by higher revenues once more hydrogen consumers are connected to the network. This delaying of fees means that later users will thus also help to carry the costs of expanding the network. This prolongation of fees over time is justified, as later users will benefit from an adequately dimensioned network and a successful ramp-up.

In the early ramp-up phase, the cap on the ramp-up fee will lead to a gap between high investment costs and low revenues from network fees due to the low number of initial users. This shortfall can be financed in the interim by an amortisation account. If more users are connected to the network at a later time and the revenue from network fees surpasses the costs for network expansion and operation, the accrued deficit in the amortisation account will be offset. Should the amortisation account not be balanced out by 2055 for reasons that are not foreseeable at present, a subsidiary state guarantee will come into force. In this case, the Federation would balance out the remaining deficit, with the operators of the hydrogen core network contributing a co-payment of up to 24 percent of the shortfall. With a target year of 2055, a long term was selected for the amortisation account to ensure that full financing via network fees is possible even in the event that the hydrogen ramp-up is delayed.

The Federal Government is creating a state guarantee for the case that the hydrogen ramp-up should fail, contrary to the Government’s own plans and expectation, or take a much slower pace than experts currently predict. This is because, especially in transition phases, innovations and changes can occur that could have effects on the demand for hydrogen that are unforeseeable at present. If, for example, the development of a “super battery” or other methods revolutionise energy storage or if value chains change, this could lead to a long-term slump or lack of demand for hydrogen. In scenarios of this nature, which are unlikely, the network fee revenues would fail to materialise, the state would have to balance out the deficit in the amortisation account and the hydrogen core network operators would have to contribute the aforementioned co-payments. This subsidiary state guarantee is therefore important to remove any remaining uncertainty that private investors may have regarding the success of the hydrogen ramp-up. This is how we will solve the “chicken vs. egg” problem.

The goal of the core network is to lay a foundation for an expandable hydrogen infrastructure in Germany as quickly and efficiently as possible. This is why the first step is to realise the supra-regional transport level, as this enables a rapid ramp-up of the hydrogen market via the expansion of an efficient, expandable, quickly realisable, and climate-friendly hydrogen core network across all of Germany. Further expansion occurs from the second stage as part of integrative network development planning for gas and hydrogen.

Natural gas distribution system operators (DSOs) can make an important contribution to the expansion of the hydrogen infrastructure in Germany. The repurposing of existing gas distribution network infrastructure and the connection of hydrogen customers to the hydrogen infrastructure via the distribution network is an important element of the success of the hydrogen ramp-up. While the focus of the core network is on the supra-regional transport level, the distribution networks (regional and local networks alike) create the connections from the supra-regional transport network to the end customer (first and last mile delivery). A significant portion of the existing high-pressure gas pipelines are currently operated within the distribution network area. The regional distribution of hydrogen is crucial in order to be able to supply hydrogen locally to industrial customers, storage facilities, electrolysers and producers in the future. For hydrogen distribution network operators, the regulatory and legal framework have been further developed within the scope of the implementation of the European directive regulating gas and hydrogen on the internal markets.

As a second stage building on the hydrogen core network, a comprehensive, regular Network Development Plan for hydrogen is planned. This planning should take place together with the network development planning for gas in an integrative process in order to take account of interplay between the sectors and to make use of the synergies.

To this end, ongoing network development planning for hydrogen and gas has been established in the Energy Industry Act and the necessary legal and regulatory framework put in place. Transmission system operators and regulated operators of hydrogen transport networks will thus come together every two years within the scope of an integrative process to create a scenario framework and a Network Development Plan for gas and hydrogen based on this framework. The respective modelling of the long-distance gas transmission system and the hydrogen transport network will then take place based on standardised national parameters. A coordination office (https://ko-nep.de/en/) has been set up to accompany and support the integrative process of network development planning.

As the first stage of the network expansion, the hydrogen core network forms the basic framework for the expansion of the hydrogen infrastructure in Germany – it is the first step in a developing market. This basic framework should then be continuously further developed within network development planning. The goal of this second stage is to build an efficient hydrogen network on the basis of regular scenario and demand-based hydrogen network development planning in order to enable a secure and reliable energy supply.

The core network application submitted by the TSOs (see https://www.bundesnetzagentur.de/DE/Fachthemen/ElektrizitaetundGas/Wasserstoff/Kernnetz/start.html (in German only)) is currently being examined and will again be subject to public consultation. The deadline for responses to the Bundesnetzagentur is 6 August 2024. The Bundesnetzagentur is then to issue an approval or any change requirements within two months. Once approval has been granted, the implementation of the core network can begin, allowing the first core network pipelines to come on stream as planned in 2025.
A draft scenario framework for a Network Development Plan was presented on 1 July 2024 as part of the future ongoing network development planning for gas and hydrogen, and contains underlying assumptions about the expected development of the extraction or production, supply and consumption of gas and hydrogen. The Bundesnetzagentur is to consult on this before the end of year. Building on this, the first integrated Network Development Plan for gas and hydrogen is to be created by 31 May 2025 and confirmed by the Bundesnetzagentur by 30 June 2026.