Assessment of system effects of large-scale implementation of offshore wind in the southern North Sea

The possible upscaling in offshore wind for 2030 and even more so for 2050 in the southern North Sea is likely to have an impact on its functioning in very fundamental ways. Large-scale extraction of wind energy from the lower part of the atmosphere may affect local wind patterns, wave generation, tidal amplitudes, stratification of the water column, dynamics of suspended particles and bedload transport of sediment. Furthermore the infrastructure will provide extra hard substrate, not only on the bed (in the form of scour protection) but also providing attachment opportunities for biota in the upper layers of the water column. Such changes to the physical functioning of the North Sea may have far-reaching consequences for the ecological functioning, such as changes to the total amount and the timing of primary production, food availability of filter feeders and higher trophic levels, and habitat suitability for many species. In this report the potentially most important effects of the possible upscaling in offshore wind in the southern North Sea and the most important knowledge gaps have been identified.