In the UK, EU and the USA, there has been an ongoing push to develop offshore wind farms, with towers and blades at a size that would dwarf anything on land. In addition, there are environmental concerns with land-based farms, ranging from raptor deaths to noise and visual impacts for nearby communities.

However, offshore is not a panacea.

A report issued last week by the US National Academy of Sciences, Engineering, and Medicine concluded that wind turbines can create two different problems. First, their steel towers can reflect electromagnetic waves, interfering with ships’ navigational radar systems in ways that might obscure nearby ships.

In addition, the report states the turbine’s rotating blades can also create a form of interference similar to the Doppler effect, in which sound waves shorten as a moving object approaches the observer. In this case, the spinning blades shorten and distort the radar signals sent from passing ships and can produce a “blade flash” on a ship’s radar screen. These flashes can create false images that look like vessels and could confuse a human radar operator on the bridge.

A concern that the US Coast Guard has is that the placement of some offshore wind farms near shipping lanes might funnel large commercial shipping traffic into designated maritime traffic lanes, making these vessels even more dependent on their radar systems, which could be compromised by wind turbine generators.