![[Translate to English:] Ein Offhore Windpark ist am Horizont zu sehen.](/fileadmin/_processed_/b/e/csm_wind-farm-2057881_93db6281c0.jpg)
Climate change can only be stopped if humanity succeeds in generating all the energy it needs from renewable sources. Wind turbines at sea – known as offshore wind farms – play a crucial role in this. They have the advantage over onshore wind turbines in that the wind generally blows stronger and more consistently at sea. Additionally, offshore wind energy is considered to have the greatest potential of all known technologies for generating electricity from renewable sources.
The potential of offshore wind power
According to calculations by the International Energy Agency, if wind farms were built in all suitable coastal regions, they could together generate up to 36,000 terawatt-hours of electricity per year. This amount would be nearly sufficient to meet the projected global electricity demand in 2040 (*).
The expansion of offshore wind energy has increased significantly worldwide over the past decade, particularly in China. With ongoing technical optimisation, today's offshore wind turbines are not only getting larger, but wind farms are also being located further from the coast, where wind conditions are more favourable. There are even concepts now for using wind-generated energy directly at sea to produce green - meaning low-emission - hydrogen and other downstream products.
The larger offshore wind farms become and the further out at sea they are located, the greater the need for cross-border cooperation between all coastal states involved. Uniform standards, regulations, and approval procedures are also necessary, particularly concerning marine protection(*).
As of March 2024, there are 29 offshore wind farms in operation in Germany, most of which are located in the North Sea. The smallest farm, Alpha Ventus, has twelve wind turbines, while the largest farms, such as Meerwind and Baltic 2, have 80 turbines each.
Individual offshore units are enormous wind turbines, which are expected to become even larger in the future to achieve outputs of eight megawatts or more. Plans for future projects up to 2025 foresee significant increases compared to existing turbines. Depending on the project, rotor diameters may range from 174 to 236 metres, and hub heights could reach up to 145 metres. For comparison, Cologne Cathedral is around 150 metres tall.
Integrating marine environmental protection from the outset
Offshore wind farms impact marine ecosystems through various interconnected physical, biogeochemical, chemical, and biological processes at every stage: planning, construction, operation, and ultimately dismantling and decommissioning. For instance, it has long been known that installing fixed foundations for wind turbines generates significant noise, which, without appropriate countermeasures, can drive marine life away from their natural habitats. Issues may also arise above sea level, particularly when wind farms are built directly in bird migration pathways.
To date, offshore wind farms have been a key component of sustainable marine management. The precise effects of planned wind farm expansions in the North Sea and Baltic Sea on marine ecosystems and other activities, such as fishing, are currently under study. Alongside environmental impacts, social and planning aspects are also being examined to provide actionable, solution-oriented insights.
