Presentation on theme: "Netherlands Institute for Radio Astronomy 1 ASTRON is part of the Netherlands Organisation for Scientific Research (NWO) Wind turbines and LOFAR Hans van."— Presentation transcript:
Netherlands Institute for Radio Astronomy 1 ASTRON is part of the Netherlands Organisation for Scientific Research (NWO) Wind turbines and LOFAR Hans van der Marel ASTRON Wind Turbine meeting, Chalmers
2 LOFAR Low Frequency Array 10 - 90 MHz (LBA) 110 - 250 MHz (HBA) Arranged in stations Station connected with fibres Station correlation Central correlator (Groningen)
3 LOFAR locations Core Remote stations International stations
4 LOFAR core and environment Large receiving surface Short baselines Susceptible to interference Radio quiet zone coordination zone of ~ 6 km Wind turbines!
5 Wind turbines in Drenthe Up to 200 MW in 2020 At least 3 MW per wind turbine Clusters of at least 5 wind turbines No wind turbines in LOFAR zone 1 (radio quiet zone) Only wind turbines in LOFAR zone 2 (coordination zone) if they do not impede the LOFAR project
6 Windfarm Hondtocht LOFAR monitoring survey in October 2006 Local authority: Dronten (Flevoland) Wind turbine:Vestas - V66 - 1,75 MW Number of wind turbines: 8 Installed capacity:14,75 MW Rotor axis height:67 metres Rotor diameter:66 metres Measurements by: Mark Bentum and Harm-Jan Stiepel Processing by: Rob Millenaar and Albert-Jan Boonstra
15 Conclusions Electronics is potential source of emission Partly shielded by wind turbine structure Might be different for other wind turbines Amplitude modulation due to variable reflections For LOFAR frequencies AM on already distorted channels due to dispersion More investigations needed: Emission and reflections of bigger wind turbines and other types Dispersion and reflections at higher frequencies