The next crop of wind farms will grow at an unprecedented speed – and will leave a shorter time than ever before to assess their impact on radiocommunications.
The British government is clearing the path for green energy in a bid to meet its target of generating 20% of UK electricity requirements from renewables by 2020. The government’s enthusiasm for this is seeing it streamline the planning process for wind turbines, and that means radio spectrum users will have less time to assess and make representations about the potential impact on their services.
“ATDI has been arguing for a long time that the radiocommunications industry shouldn’t let wind farms just creep up on them,” says Paul Grant, ATDI lead engineer. “That is truer than ever now that the opportunity to object to any plans is being reduced.”
In the summer, the Department for Business, Enterprise and Regulatory Reform introduced a memorandum of understanding – signed by, among others, the Ministry of Defence (MoD), the Civil Aviation Authority (CAA) and the Department for Transport – agreeing that the MoD will shorten pre-planning consultation times and the CAA will work to find speedy solutions to any conflicts between air traffic control and turbine developers. The memorandum is due to be implemented by the end of the year.
The government’s enthusiasm for rapid growth of wind farms and its preparedness to accept reduced consultation times is illustrated by business secretary John Hutton who said at the launch of the memorandum of understanding: “This agreement represents real progress towards removing a barrier to the expansion of wind power while ensuring air safety and national security. This will lead to faster consenting decisions.”
Paul notes: “What this means in practice is that fast and accurate assessment of the impact on radio users is increasingly vital. When the wind turbines are built, nobody is going to tear them down again so it is essential that problems are analysed and overcome before the structure is put up.”
ATDI has been working in this area since the company’s founding 12 years ago and, in July, ran a seminar to address the impact of wind farms on air traffic control radars and radio communications infrastructure.
The Joint Radio Company (JRC), the organisation set up by the energy industry to oversee the communication issue, notes: “Although turbine blades are not of metallic construction they can nevertheless reflect and diffract radio waves. The lightning protection schemes built into turbine blades can further enhance their reflective radio properties. This reflection can, under certain conditions, cause interference.”
JRC has been investigating the effects of turbines on the UHF band over the last three years. The organisation says: “The ability of UHF telemetry systems to operate over obstructed paths is the feature that creates the greatest potential for incompatibility with wind turbines. Because the wind turbines frequently occupy the higher ground and protrude above the landscape and because they act as massive radio reflectors, there is considerable scope for performance degradation.”