The higher the wind turbine, the better
Hereon researchers have found out: Large new-generation wind turbines have less impact on their surroundings
Wind farms in the North Sea can slow each other down and also affect marine life. Scientists at the Helmholtz Center Heron have now discovered that these effects do not necessarily have to increase with the future expansion of offshore wind energy. On the contrary: the trend is towards ever taller wind turbines, which obviously have less impact on the ocean. This can relieve the pressure on marine habitats and at the same time increase the electricity yield.
Wind farms affect their surroundings because the rotation of the rotors causes air to swirl. This causes turbulence behind a wind farm. The wind speed is also lower there. For a wind farm located behind another wind farm, this means a lower electricity yield. As Dr. Naveed Akhtar and his colleagues described two years ago in a specialist article, wind turbines also affect marine life.
Using computer model calculations, they were able to show that the growth of planktonic algae in particular is altered. Behind a wind farm, it can be up to ten percent lower than in other marine areas. The reason for this is the decreasing wind and the increased turbulence behind the wind turbines. The energy transferred to the ocean decreases in these regions due to the reduction in wind speed. The spatially non-uniform wind fields near the water surface also generate compensatory movements in the ocean, which lead to vertical transport – so-called upwelling and downwelling – and can either increase or decrease plankton production.
The Hereon researchers‘ new study is special because it presents the situation for the entire North Sea. „Usually, calculations of this kind only take into account the impact of individual wind turbines or just one wind farm,“ says Naveed Akhtar. „However, in view of the strong expansion in large areas of the North Sea, you have to look at the entire area. Wind farms have a long-distance effect that can reach 60 to 70 kilometers. To take all this into account, you have to look at the entire North Sea.“ (Source: Hereon Press Release)
Read the complete Hereon Press Release:
==> The higher the wind turbine, the better
Akhtar, N., Geyer, B., & Schrum, C. (2024): Larger wind turbines as a solution to reduce environmental impacts. Sci Rep 14, 6608 (2024), doi:10.1038/s41598-024-56731-w
Abstract:
The EU aims for carbon neutrality by 2050, focusing on offshore wind energy. Investments in North Sea wind farms, with optimal wind resources, play a crucial role. We employed a high-resolution regional climate model, which incorporates a wind farm parametrization, to investigate and address potential mitigating impacts of large wind farms on power generation and air-sea fluxes. Specifically, we examined the effects of replacing 5 MW turbines with larger 15 MW turbines while maintaining total capacity. Our study found that substituting 15 MW turbines increases the capacity factor by 2–3%, enhancing efficiency. However, these turbines exhibit a slightly smaller impact on 10 m wind speed (1.2–1.5%) and near-surface kinetic energy (0.1–0.2%), leading to reduced effects on sea surface heat fluxes compared to 5 MW turbines. This was confirmed by a stronger reduction in net heat flux of about 0.6–1.3% in simulations with 5 MW compared to 15 MW wind turbines. Air-sea fluxes influence ocean dynamics and marine ecosystems; therefore, minimizing these impacts is crucial. Overall, deploying 15 MW turbines in offshore wind farms may offer advantages for ocean dynamics and marine ecosystems, supporting the EU’s carbon–neutral objectives.
