Transformation of the global energy system is essential to achieve the targeted climate protection goals. Key measures to mitigate further increases of emissions demand a massive push in clean electrification and energy innovations. This calls for environmentally friendly installation of reliable and clean offshore renewables energies (ORE) by means of harvesting wave, tidal current or wind energy etc.! Globally, offshore wind energy is regarded as one of the key future technologies to achieve these objectives. The talk regards the above sketched settings and portrays the demands being set in European waters, i.e. EU Green Deal (2020), Ostende Declaration (2023). Insights will be provided into the Collaborative Research Centre CRC1463 funded by the German Research Foundation (DFG) on the integrated design and methodological operations of Offshore Megastructures by means of developing and testing so-called "digital twins" in order to focus on advancing knowledge on structural degradation and ageing engineering infrastructure and devices in harsh marine environments, e.g. fatigue, deterioration, malfunctioning etc! Finally, a brief overview on world-class laboratory facilities and portfolio of research projects will be given incl. the new Large Wave-Current Flume (GWK+) that just recently went into operation representing a unique maritime test infrastructure on its own.