Qinetiq coating allays wind farm fears

Qinetiq claims a non-metallic composite holds the key to tackling interference to radar caused by wind turbines.

More than a third of proposals for wind farm developments are being rejected by the MoD because they interfere with aircraft radar, although the technology already exists to tackle the problem.

Chris Shears, The British Wind Energy Association’s representative for MoD issues, said that at the moment about 40% of applications for onshore wind farms and about 30% of offshore developments are being rejected by the MoD.

Five of the 18 sites currently proposed for large offshore wind farms – four off the coast of Lancashire and a fifth off Cromer in Norfolk – are being blocked over fears they will interfere with radar screens.

Wind farms can cause double imaging or spurious images on air traffic control radar screens, or make an aircraft ‘disappear’.

But technology to manage the effects of wind farms on radar has already been developed by innovation specialist Qinetiq. The company has a method for applying new non-metallic composite materials to the structures.

These have electromagnetic properties to manage the signal, by absorbing some of the radar energy and preventing scattering, said Dr Stephen Mason, marketing development manager for renewables at Qinetiq.

The materials do not make wind farms invisible, as this could lead low-flying aircraft to crash into them, but they mitigate the most problematic effects.

‘It is a real safety concern, but can be managed through the application of the right technologies. We can tailor this technology to the specific situation and type of radar,’ said Mason.

Qinetiq’s technology is cost effective, he said. ‘If you compare the cost of applying the technology to the cost of building a new wind farm, it is very small.’Qinetiq, in its former incarnation as the government’s Defence Evaluation and Research Agency, has spent several years studying the effect of structures and aircraft on radar.

‘The MoD has genuine concerns, and we are working to provide solutions to clarifythe situation and bring the BWEA and MoD to an agreement. It is a complex problem, but one we can address,’ said Mason.

The BWEA has commissioned a report into the extent of the problem, and what can be done to tackle it, said Shears.

‘We want to reduce the number of sites being blocked, and determine what can be done to mitigate the effects of wind turbines in sensitive areas,’ said Shears.

An MoD spokesman denied wind farm developments were being blocked, but said the department raises concerns about particular proposals. The MoD is conducting research into the issue with the DTI, to determine the impact of wind farms and what can be done to tackle it, he said.

‘If that [the Qinetiq technology] was found to be an option, we would look at getting around the problem in that way. But we will also be looking at it from the point of view of our own radar technology, and what we can do on our side to solve the problem,’ he said.

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