Germany’s ambitious goal of achieving carbon neutrality by 2045 necessitates a substantial expansion of renewable energy generation, with offshore wind playing a critical role alongside onshore resources. The country aims to scale up its offshore wind capacity to 30 GW by 2030 [1], nearly quadrupling the installed capacity reported by the end of 2024[2]. This rapid growth brings not only technical and logistical challenges related to infrastructure deployment but also significant implications for grid stability and integration.

To address these challenges, German transmission system operators (TSOs) Amprion and 50Hertz introduced the Offshore Grid Connection Rules (ONAR) in 2023. These guidelines aim to streamline the connection of offshore wind farms to the extra high-voltage grid and are closely linked to the national Technical Connection Rules (TCR), namely VDE-AR-N 4130 for extra-high voltage systems and VDE-AR-N 4131 for HVDC-connected generation units.

Unlike the well-established onshore grid connection process, ONAR represents a relatively new framework that, in several areas, remains subject to interpretation. This presentation seeks to clarify the offshore grid connection procedure as outlined in ONAR, highlighting key process elements and sharing practical insights from recent project implementations. Special attention is given to the requirements for simulation models and model validations, including the conformity studies and documentation necessary for obtaining Interim Operational Notification (ION) and Final Operational Notification (FON) from the respective TSOs.

The presentation will conclude with a set of practical recommendations aimed at enhancing regulatory compliance and supporting grid stability, based on lessons learned from ongoing offshore wind integration projects in Germany.

[1] https://www.bundesregierung.de/breg-de/service/archiv/windenergie-auf-see-gesetz-2022968

[2] https://www.offshore-stiftung.de/en/status-quo-offshore-windenergy.php