A peer-reviewed Chinese study has found that offshore wind farms can degrade shore-based radar performance, creating detection blind spots and generating false 'ghost' targets that could complicate maritime safety in coastal waters. The research, published last month in the journal Radio Engineering, delivers one of the more detailed quantitative assessments of wind turbine interference on marine radar to date.

Key findings: coverage loss and blind spot expansion

The research team determined that at a range of 5 kilometres (3 miles), effective radar coverage declined by 6.9 per cent while blind spots expanded by 14.9 per cent. These figures point to a measurable operational impact on the ability of shore-based systems to track vessels in the vicinity of turbine arrays.

The study was led by Professor Liu Zunnian and his team from Qingdao Technological University in collaboration with the Yantai Communication Centre of the Beihai Navigation Security Centre, an agency operating under China's Ministry of Transport. The institutional pairing — an academic engineering faculty alongside a national navigation safety body — lends the findings particular operational weight.

The 'ghost target' problem

Beyond coverage reduction, the researchers identified a secondary hazard: large arrays of wind turbines can reflect radar signals in ways that produce false or 'ghost' target returns. In practice, this means radar operators could register phantom vessel contacts in areas actually occupied by turbine structures, adding noise to an already complex surveillance picture.

The phenomenon arises because turbine blades and towers are highly radar-reflective surfaces. When signals bounce off multiple turbine elements, the resulting multi-path returns can mimic the radar signature of a genuine maritime vessel, according to the study's authors.

Why it matters for maritime safety

China is among the world's largest and fastest-growing offshore wind markets, with substantial development concentrated along its eastern and southern coastlines — including Shandong province, where both Qingdao and Yantai are located. As turbine arrays scale in size and move closer to busy shipping lanes, the interference footprint on coastal radar networks is expected to grow proportionally.

The concern is not unique to China. Regulators and defence agencies in the US, the United Kingdom, and across Europe have raised similar questions about wind farm interference with both civilian maritime radar and military air-defence systems. The Global Wind Energy Council has previously acknowledged radar compatibility as a key permitting challenge for large offshore projects worldwide.

What's next

The study, appearing in the Chinese journal Radio Engineering, is expected to inform ongoing regulatory and engineering discussions around wind farm siting and radar mitigation technology. Approaches under broader industry consideration include stealth coatings for turbine structures, radar gap-filler installations, and algorithmic filtering to suppress ghost returns.

As offshore wind capacity continues to expand globally, the pressure on regulators to establish binding radar-compatibility standards — and on turbine manufacturers to engineer around the interference problem — is likely to intensify in the months ahead.