12 MW wind turbines, the scientific basis for their operational 70 to 270 m height offshore

Improvement of offshore winds and turbulence predictions based on available remote sensing equipment, wind and turbulence quantification, and modelling.

12 MW wind turbines: the scientific basis for their operational 70 to 270 m height offshore. The 12MW project runs in years 2005 and 2009 with funding from the Danish Research Agency, The Strategic Research Council, Program for Energy and Environment.

Background
Wind turbine dimensions have evolved from rapidly 1980 to now. At the moment turbines up to 8 MW can be tested at Høvsøre Test Station, Risø. The size of commercial wind turbine design may grow to 12 MW. The very large turbines will be used offshore. This development puts a strong demand on our understanding of the atmospheric flow and turbulence characteristics at very high heights offshore.

Dimensions of multi-MW wind turbines are listed in the table



Small turbines operate in the lower part of the atmospheric boundary layer. Here the logarithmic wind profile is valid and turbulence statistics are well known from offshore and coastal masts. Higher up winds are largely unknown due to severe practical offshore measurement difficulties.

The challenge is to improve our knowledge on offshore wind and turbulence characteristics for the next generation of multi-MW wind turbines that will come to operate at heights ranging from 70 to 270 m above sea level.

In the 12MW project we will improve offshore winds and turbulence prediction capabilities at these heights based on available new and proven remote sensing equipment, wind and turbulence quantification, and modelling.

Goal
The goal of the project is to experimentally investigate the wind and turbulence characteristics between 70 and 270 m above sea level and thereby establish the scientific basis relevant for the next generation of huge 12 MW wind turbines operating offshore. This will be done using state of the art wind remote sensing measurement techniques for data collection at an offshore wind farm site in Denmark.

The strategic aim is to supply the wind industry relevant results.

Objective
To establish new wind and turbulence design models for the next generation of 12 MW turbines operating in the offshore marine environment from 70 to 270 m’s height. The design models will be evaluated from observations from Doppler Laser LIDAR, SODAR, backscatter aerosol LIDAR, radiosondes, ceilometer and satellite.

Participants
Risø National Laboratory, Wind Energy Department, Charlotte Bay Hasager (PI), Torben Mikkelsen, Ioannis Antoniou, Rebecca Barthelmie, Sven-Erik Gryning, Hans E. Jørgensen, Ph.D. student Alfredo Peña

Elsam Engineering: Paul Sørensen

References
Pena, A.; Gryning, S.-E.; Hasager, C.B., LiDAR observations of offshore winds at future wind turbine operating heights. 2007 European offshore wind conference and exhibition, Berlin (DE), 4-6 Dec 2007. Unpublished. Paper available

Hasager, C.B.; Peña, A.; Mikkelsen, T.; Courtney, M.; Antoniou, I.; Gryning, S.-E.; Hansen, P.; Sørensen, P.B., 12MW Horns Rev experiment. Risø-R-1506(EN) (2007) 83 p.

Hasager, C.B.; Astrup, P.; Christiansen, M.B.; Nielsen, M.; Pena, A., Mapping of offshore wind resources. Meeting between a Taiwanese delegation and Wind Energy Department at Risø, Risø (DK), 11 Oct 2007. Unpublished. PowerPoint presentation available

Pena, A.; Hasager, C.B.; Gryning, S.-E.; Courtney, M.; Antoniou, I.; Mikkelsen, T.; Sørensen, P., Offshore winds using remote sensing techniques. International conference: The science of making torgue from wind, Lyngby (DK), 28-31 Aug 2007. J. Phys.: Conf. Ser. (2007) 75 , 11 p.

Peña, A.; Hasager, C.B.; Gryning, S.-E.; Courtney, M.S.; Sørensen, P., Evaluation of the offshore wind resource using LIDAR. EGU General Assembly 2007, Vienna (AT), 15-20 Apr 2007. Geophys. Res. Abstr. (CD-ROM) (2007) 9 (no.Abstr. EGU2007-A-11467)

Contact

Charlotte Bay Hasager
Professor
DTU Wind
+45 46 77 50 14