14 March 2025. Statement by the AquaVentus Förderverein on the consultation regarding the informative presentation in Annex 3 of the Site Development Plan 2025 of 28 February 2025
Introduction. The AquaVentus Förderverein comments on the consultation on Annex 3 of the Site Development Plan 2025, which contains an informative presentation of one variant of future determinations in areas N-14 to N-20 (Zones 4 and 5). The consultation takes place within a very tight timeframe — only five days after the federal election and with a response period of just ten working days. This makes a thorough substantive engagement with the subject, as well as detailed feedback within the association from its members, very difficult.
Beyond this, apparent contradictions can be identified in the presentation that have material consequences for the planning basis. The total site volume of the areas considered — N-14, N-16, N-17, N-19 and N-20 — amounts to 27.8 GW according to the tabular presentation in the consultation. Annex 3 of the FEP (page 165) states approximately 26.5 GW. At the same time, the listing takes account of 10 offshore grid connection systems (ONAS) which, at a capacity of 2 GW, could transport only 20 GW, and at a capacity of 2.2 GW a total of 22 GW. This yields a connection ratio of 71.9 % and 79.1 % respectively, which appears inconsistent with the connection ratio of at least 83 % presented in Annex 3 of the FEP (page 164). The implementation of peak shaving does not appear comprehensible, and its technical and macroeconomic effects should urgently be examined more deeply and comprehensively before long-term determinations are made in the FEP. The AquaVentus Förderverein therefore sees itself in a position to answer only questions 7, 8 and 9 of the consultation.
Answers to questions 7, 8 and 9. Question 7: How is the approach of a mandatory wind farm capacity exceeding the associated grid connection capacity, known as peak shaving, assessed in principle?
Peak shaving can in principle be assessed positively, provided certain conditions are met that make the entire wind energy usable. Above all, peak shaving will inevitably raise the question of whether the offshore wind farm capacity exceeding the grid connection capacity cannot be used otherwise. Offshore electrolysis suggests itself as the solution. Introducing peak shaving should therefore necessarily be accompanied by the introduction of offshore electrolysis with combined connection concepts. It is decisive that combined connection concepts be permissible under the Offshore Wind Energy Act, which enables a more flexible grid connection. Through the efficient and mutually coordinated combination of energy transport via submarine cable as electricity and via pipeline as hydrogen, installation costs can be reduced while at the same time increasing overall macroeconomic returns. The utilisation of the offshore electricity grid infrastructure is also increased. Detailed explanations can be found in the E-Bridge study and in the Fraunhofer IEE study, both from 2024. In addition, offshore electrolysis (hydrogen generation at sea) should be developed further as a key technology and brought to market maturity in order to convert so-called surplus electricity sensibly into hydrogen and thus maximise the use of renewable energies. It may be assumed that increasing ONAS capacity and peak shaving were proposed for reasons of greater cost efficiency, since savings on HVDC systems could appreciably reduce the costs of offshore grid expansion. Large-scale offshore electrolysis must be considered as an option for the cost-efficient expansion of offshore energy. Technical implementation can presumably take place via "offshore energy hubs". This follows from the fact that several ONAS are replaced by the AquaDuctus hydrogen pipeline provided for in the core network. Peak shaving in combination with innovative grid connection solutions increases cost efficiency and makes optimal use of the existing infrastructure.
Question 8: What business effects on offshore wind farm operators do you expect from peak shaving?
The business effects of peak shaving are difficult to quantify precisely, as they depend strongly on the respective site and the specific framework conditions. A first analysis is provided by the accompanying expert report of Fraunhofer IWES with an ad-hoc analysis. Key findings from this investigation show that while peak shaving leads to measurable revenue losses, it simultaneously increases grid utilisation, which must also be taken into account in the onshore grid in particular. The revenue losses vary by site and scenario within Zones 4 and 5 and lie between -6.5 % and -9.8 %. Area N-19 is particularly affected, where a revenue loss of up to 9.2 % was found in Scenario 24.
In total, the annual revenue loss amounts to 6.3–6.9 TWh, corresponding to forgone hydrogen production of up to 200,000 tonnes from offshore electrolysis. It must be assumed that offshore wind farm operators will demand compensation for this revenue loss if this energy cannot be stored and used otherwise. Without such compensation there is no economic incentive to change the previous connection ratio of 1:1.
Question 9: In your view, which connection ratio should be chosen specifically, and for which areas and sites, for the region west of shipping route SN10?
The connection ratio (ONAS rated capacity / offshore wind farm rated capacity) can, through the deployment of a developed offshore electrolysis, be even lower than assumed in the current investigation. This would allow the number of offshore grid connection systems (ONAS) required to be reduced, saving further costs and capturing efficiencies. Relevant assumptions for this arise from various sources. The Electricity Network Development Plan 2037/2045 states that the new-build costs of a 525 kV HVDC cable for 2 GW vary, depending on design, between EUR 6.6 million and EUR 7.6 million per kilometre. The savings potential per ONAS is thus estimated, for an exemplary line length of 330 km, at EUR 2.2 to 2.5 billion. The reduction from 16 to 12 ONAS sought in the FEP thus yields a savings potential of EUR 8.8 to 10 billion, which is in turn reduced by compensation payments to the offshore wind farm operators (see the answer to question 8). In addition, the TYNDP 2024 provides important assumptions for alternative grid connections. Particularly relevant is that the increased deployment of offshore electrolysis (hydrogen generation at sea) could save further ONAS, thereby avoiding peak shaving and thus the non-use of wind energy. Moreover, combined connection concepts can — compared with purely expanding the electricity grid — achieve macroeconomic savings of up to EUR 31 billion.
Conclusion. AquaVentus supports peak shaving if the peak-shaved wind yields are made usable through combined connection concepts, thereby further optimising the efficiency and economic viability of offshore wind energy. Hydrogen generation at sea increases cost efficiency in offshore wind expansion, particularly in distant areas such as Zones 4 and 5.
In our view, blanket peak shaving and thus the non-use of wind energy is not expedient without considering innovative solutions, because it does not save costs. The compensation payments then due may even — contrary to the actual objective — contribute to an increase in energy costs. In addition, the presented sites and grid capacities require more careful examination in order to shape the planning basis realistically. The legislator should therefore anchor large-scale offshore electrolysis on the order of 10 GW in the expansion target of the Offshore Wind Energy Act and incorporate it into offshore planning.