Titel: Report from flight test RADAR
Författare: Energimyndigheten
Utgivare: Energimyndigheten
Årtal: 2009
Sökord/Keywords: offshore, wind turbine, radar, conflicts, WRAP, Swedish Armed Forces, FM, Defence Materials Administration, FMV
Rapport (Pdf)
Sammanfattning/Abstract: With the support of the Swedish Energy Agency (STEM), the Swedish Armed Forces (FM) and the Defence Materials Administration (FMV) have carried out an investigation into the problems of interference of coastal radar by offshore wind turbines. The investigation consisted of flight tests and simulations, as well as examination of work carried out abroad and experience drawn from this work. The results of these investigations show that the ability of radar to detect targets is reduced behind a wind turbine. The extent of the interference from a wind turbine correlates closely with results from simulations carried out by the Swedish Defence Research Agency (FOI). Calculations by the currently used planning tool WRAP ObsMan indicates results that correspond to a great extent with simulations and measurements.
The level of requirements, or rather the way of formulating requirements for FM to be able to give a positive opinion for the expansion of offshore wind turbines that is currently needed for an “approval” in WRAP ObsMan is not appropriate however, since it does not provide sufficient flexibility. Current requirements result in almost all considerations so far giving negative results. Among other things, the size of the target (radar target area) does not affect the result. A new way of formulating the requirement and a better presentation of the calculated results are required.
With the broadened and improved knowledge gained after tests carried out, there are now better conditions than earlier for determining the consequences of offshore wind turbines with respect to their influence on FM air and surface radar surveillance. With the aid of improved performance tools, calculated results can be better evaluated in the current operative3 scenario, in which consideration is taken to other radar stations and other sources of information that can cover the “shadowed” areas.
Only using calculation tools as a basis for an opinion by FM regarding the development of offshore wind turbines in a certain area is not appropriate. The calculation result shall be included as part of the decision information. A presentation tool in which the influence on a radar’s performance is indicated in a more reliable fashion, as well as a composite radar coverage image for the area, can provide the required decision information. Each case must be judged on its own merits, in which FM requirements are applied with consideration to the current operative situation.
In section 6 a description is given of how FM intends to handle referrals for consideration regarding the development of offshore wind turbines and which prioritised measures in the short and long term are either planned or proposed.
With the examination model for referrals for consideration that is now proposed, FM judges that most of the development of offshore wind turbines can be solved in terms of radar conflicts. One requirement for positive solutions is that a dialogue is established at an early stage with the operators, and that the requisite adaptation measures are carried out when necessary. Such measures may include, for example, the adaptation of the number and location of turbines in a wind farm, the establishment of radar next to a wind farm or measures for existing coastal radar (supplements, moving, raising masts).
Costs related to measures for handling interference from wind turbines on FM sensor and communication systems that require FM to give a positive opinion shall be paid by the wind turbine project in question, or in another way outside FM’s budget.