Deadly Interference: Offshore Wind Turbines Wrecking Marine Radar Signals

Radar is critical to safe marine navigation, and pilots, both domestic and military, particularly when the weather turns sour. With offshore wind turbines the perfect radar signal wreckers, you’d think they were designed as some form of enemy espionage.

Wind turbines standing on columns 100-150m or more above sea level, with the tips of their 50-80m blades clocking 350 kph play havoc with radar systems, giving false images and distorting real ones. The result is unnecessary danger for pilots dependent upon accurate weather reports, and air traffic guidance, both essential for safe takeoffs and landings.

In a number of States, the US military has obtained legislation to prevent the construction of wind turbines anywhere near their airfields and training grounds.

With thousands of these things now spinning in clusters miles offshore, the loss of effective radar navigation is another (wholly unnecessary) danger created by a thoroughly unreliable power source that wouldn’t exist without subsidies, as the team from Jo Nova report below.

Offshore Wind Turbines Could Mess With Ships’ Radar Signals
Jo Nova Blog
Jo Nova
29 May 2024

We found out last year that offshore wind turbines scramble Air Force Radars. RAF pilots already use the turbines in training exercises to help them hide. But ships also use radar and a new study quietly reported a couple of years ago that offshore wind turbines will interfere with shipping radar, may cause collisions, and interfere with search and rescue. The 2022 report was from the National Academies of Sciences, Engineering, and Medicine in the US.

But it’s OK right, we just need to upgrade all the old radar systems, keep boats out of the area, or wrap the blades of the turbines in the same material we use on stealth aircraft. (That will add to the costs of wind power). No doubt GPS and AI systems can help, but radar adds an independent and well developed layer of safety. Who wants to purely rely on the satellite connection on a stormy night?

And after we’ve built all the wind towers, upgraded the boats and planes, then we can build the second and third generation of turbines and fill holes in the ground with the waste from the first. After we’ve paid for that and for the collisions and lives lost, and the whales killed, and the porpoises deafened, we hope that in one hundred years the rain will be more evenly spread, and the storms more well behaved. It’s like the neolithic raindances never ended.

You never know, maybe some groups will benefit from the radar noise — like drug runners, pirates and people smugglers?

Unfortunately wind turbines are usually built close to shore, where our shipping lanes often are…

Offshore Wind Turbines Could Mess With Ships’ Radar Signals
Eric Niiler, Wired, March 2022

It turns out that massive wind turbines may interfere with marine radar systems, making it risky for both big ships passing through shipping channels near offshore wind farms and smaller vessels navigating around them. While European and Asian nations have relied on offshore wind power for more than a decade, the big wind farms proposed off the US continental shelf are larger and spaced further apart, meaning that ships are more likely to be operating nearby. These farms are proposed along the East Coast from Massachusetts to North Carolina, as well as for a handful of locations off the California coast, according to data from the US Bureau of Ocean Energy Management.

A panel of experts convened by the National Academy of Sciences, Engineering, and Medicine concluded in a report issued last week 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 a nearby boat.

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 what’s called “blade flash” on a ship’s radar screen. These flashes can create false images that look like boats and could confuse a human radar operator on the bridge.

“If you have something that’s moving toward you and you are illuminating it with a radar signal, then the signal that is returned will actually have what’s called a phase shift. Essentially, it appears that you have the object coming closer,” says Jennifer Bernhard, professor of electrical and computer engineering at the University of Illinois Urbana-Champaign and a member of the National Academies panel that produced the report. Bernhard says that phenomena does not completely block the radar image, “but it does create clutter “…

There are no easy answers:

While the report offered some ways for mitigation, it noted that there is “no simple modification” that could allow marine vessel radar to operate in “the complex environments of a fully populated continental shelf wind farm.”

Deadly open-seas collisions and hampered search and rescue efforts
Disrupted radar systems are not mere hassles of dealing with cluttered displays. They can result in deadly open-seas collisions. The turbines can “cast radar shadows, obfuscating smaller vessels exiting wind facilities in the vicinity of deep draft vessels in Traffic Separation Schemes.”

The US Coast Guard wrote about this last year:

Offshore Wind Energy: A Rising Challenge to Coast Guard Operations
… offshore wind turbines have been shown to affect the capabilities of the Coast Guard’s Search and Rescue Optimal Planning System (SAROPS), which is used for drift modeling and search planning. The oscillating rotor blades and generator of a wind turbine emit high levels of electromagnetic interference that can affect high frequency radar capabilities around an [offshore renewable energy installation] (OREI).

The map suggests multiple wind plants could severely limit radar operation:

Report: Wind Turbine Generator Impacts to Marine Vessel Radar
Jo Nova Blog