Offshore wind expansion could alter Northwest European rainfall

A modeling study by the Helmholtz-Zentrum Hereon suggests that extremely large-scale expansion of offshore wind farms could regionally alter precipitation patterns in Northwest Europe. Using the COSMO-CLM regional climate model and weather data from 2008 to 2017, researchers simulated the effects of wind turbines across the North Sea, Baltic Sea, and UK-Irish Sea regions.

The study found that current levels of development and planned expansions through 2030 have minimal precipitation effects, which remain largely confined to sea surfaces. However, in a theoretical upper-limit scenario involving the maximum technical use of all identified development zones, significant shifts were observed. In this extreme case, rainfall over wind farm areas could increase by 8 to 10 millimeters per month, while certain coastal areas in Germany, the Netherlands, the United Kingdom, and Denmark could see precipitation decreases of 10% to 15%.

These findings are not a forecast of specific future decades or current construction plans, but rather a controlled exercise to estimate the potential magnitude of regional climate effects. The turbines affect weather by converting kinetic energy into electricity, which slows wind speeds and increases turbulence, potentially altering how moisture moves toward land.