'Wind theft' could slow down global offshore energy push

As countries ramp up offshore wind farms to meet climate goals, scientists are warning about a growing issue: wind farms accidentally draining energy from one another — a phenomenon now nicknamed “wind theft.”

It’s caused by the wake effect — the drop in wind speed that happens behind turbines after they extract energy from the air. In large offshore wind farms, this slowdown can stretch for more than 100 km and reduce the energy output of nearby wind farms by 10% or more.

While the term wind theft is misleading — nobody owns the wind — the economic impact is real. Several developers in the UK are already in disputes, and experts warn that cross-border tensions could follow as Europe’s seas fill with turbines.

“Even small wake effects can threaten investment returns,” said Eirik Finserås, a Norwegian lawyer who studied the issue. Countries like the UK and China are now launching major research projects to better model wake patterns and plan smarter.

The EU is under pressure to triple offshore wind capacity by 2030. But without clear rules and coordination, experts say the rush to claim the best locations could trigger what’s being called a “race to the water,” potentially risking marine ecosystems and increasing energy uncertainty.

“This is not just a technical challenge,” said Pablo Ouro from the University of Manchester. “It’s a planning and policy challenge. We need to fix it — fast — to stay on track for net zero.”

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