Helmholtz-Zentrum Hereon study links offshore wind to rainfall shifts

A study by the Helmholtz-Zentrum Hereon, published in the journal Communications Earth & Environment, suggests that large-scale expansion of offshore wind farms could alter regional precipitation patterns. Using the high-resolution COSMO-CLM regional climate model, researchers simulated various expansion scenarios across the North Sea, Baltic Sea, English Channel, and Irish Sea.

The findings indicate that in a maximum technical expansion scenario by 2050, rainfall would increase over the wind farm areas while decreasing in adjacent coastal regions. This phenomenon occurs because wind turbine rotors extract kinetic energy from the wind and create turbulence. This process causes moist marine air to rise, cool, and condense, leading to increased cloud formation and precipitation directly above the wind farms. Consequently, the air moving downstream toward the coast carries less moisture.

In the simulated 2050 maximum scenario, precipitation over the wind farm areas increased by 8 to 10 millimeters per month, representing a rise of 12 to 18 percent. The researchers emphasize that these results are intended to help align the expansion of offshore wind energy in Europe with climate, environmental, and coastal protection requirements.