ADVERTORIAL


LIDAR SUPPLEMENT 09 Dr. Peter Clive


Technical Development Consultant, SgurrEnergy


Offshore performance tests at onshore prices


The expensive business of offshore wind turbine installation makes the issue of power curve testing all the more important. In onshore developments power curve testing is common, however the high cost of conducting power curve tests offshore, using masts installed on separate platforms has deterred vital verification of wind turbine compliance.


as accurate as 1st generation Lidar measurements and can be conducted at a distance of 500m.


Power curve testing deployment The level of accuracy achieved by Galion in these tests has exciting implications for power curve testing in offshore wind farms. It provides us with the opportunity to install a Galion on the transition piece of the offshore test turbine and


» The expensive business of offshore wind turbine installation makes the issue of power curve testing all the more important «


Figure 1Galion measurements captured at a distance of several rotor diameters are as accurate as mast data.


Second generation Lidars, such as SgurrEnergy’s Galion are not limited to acquiring wind data from the flow immediately above them and can make measurements of the wind anywhere within range of their laser. This allows developers to avoid the installation of expensive mast platforms and verify offshore power performance at a fraction of the cost.


Proven accuracy Figure 1 shows a comparison of two weeks of wind speed measurements acquired using conventional mast mounted cup anemometry and a Galion situated 500m from the mast. Measurements from the Galion and mast agree to a degree which satisfies the acceptance criteria normally applied to 1st generation offshore Lidar performance installed immediately adjacent to the mast. Against acceptance criteria such as the NORSEWInD project, Galion measurements are


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acquire the free stream hub height wind speed measurements necessary to test the power curve as required by IEC 61400-12-1, without incurring the cost of a platform. This configuration allows offshore power performance to be tested for costs that compare well to onshore tests, and enables many turbines to be tested, ensuring compliance and establishing confidence in the turbines.


Figure 2 Free stream hub height inflow data acquired from the transition piece – no need for a platform.


International Sustainable Energy Review Volume 5, Issue 3, 2011


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