Offshore Wind Farms Can Weaken Ocean Currents, According to New North Sea Simulations

     I have often noted that wind farms are a form of inadvertent geoengineering in that they change local wind patterns by reducing local wind speeds. New research shows that offshore wind farms also affect ocean currents and near-surface temperatures.

     New research published in Communications Earth & Environment shows that large-scale wind farms in the North Sea reduce wind velocities by up to 20% if offshore wind deployment there increases up to 10-fold by 2050, as projected. They also have hydrodynamic impacts, slowing ocean currents and heating up surface water layers.

      Phys.org explains:

“Offshore wind turbines change the air and ocean currents. The rotors extract wind energy and influence surface currents, while the turbine pillars underwater act as obstacles and slow down tidal currents. These wake structures, known as wake effects, interact with each other and determine the complex physical impacts of offshore wind farms.”

     Dr. Nils Christiansen from the Hereon Institute for Coastal Systems—Analysis and Modeling, a geophysicist and the lead researcher, notes:

"Our simulations paint a new, finely structured flow pattern that is not only evident within the wind farms but can also spread across the North Sea—with surface speeds slowing by up to 20% in an expansion scenario for 2050," says Christiansen. This can lead to large-scale changes in sediment transport or the mixing of seawater. These factors also shape the marine ecosystem.

     These potential changes in ocean currents may have other impacts, including on shipping, disaster management, environmental protection, and fisheries.

     The researchers modeled the issue with simulations and found that the distance between turbines, the location of wind farms, and local tidal conditions are decisive factors in determining the extent to which currents, temperatures, and water mixing change. In particular, spacing individual turbines further apart can reduce the turbulence caused by tidal wakes.

     While the quantification of the effects of variables is complex and mathematical, the paper explains some of the basic effects below:

“Drag from offshore wind turbine installations—both in the atmosphere and the ocean—has been shown to influence ocean dynamics at local to regional scales, leaving an impact on the marine environment. Designated to harvest energy from the wind field over the sea, wind turbines reduce the kinetic wind energy at hub height and create a downstream momentum deficit. This deficit is characterized by high turbulence from horizontal wind shear and wind speeds up to 40% lower than the ambient wind field. These atmospheric wake structures propagate both laterally and vertically behind offshore wind farms (OWFs), reaching the sea surface at distances of approximately ten rotor diameters8. Observations in the North Sea have shown that near-surface wakes can extend up to 100km downstream of large turbine clusters, depending on wind farm properties and atmospheric stability.”

 

 

References:

 

Offshore wind farms change ocean current patterns, simulations show. Torsten Fischer. Phys.org. February 16, 2026. Offshore wind farms change ocean current patterns, simulations show

Cumulative hydrodynamic impacts of offshore wind farms on North Sea currents and surface temperatures. Nils Christiansen, Ute Daewel & Corinna Schrum. Communications Earth & Environment. volume 7, Article number: 164 (January 13, 2026). Cumulative hydrodynamic impacts of offshore wind farms on North Sea currents and surface temperatures | Communications Earth & Environment