VALIDATION OF WIND SPEED DISTURBANCES TO CUPS AT THE METEORLOCICAL MAST ON THE OFFSHORE PLATFORM FINO1 USING WIND-LIDAR MEASUREMENTS Authors: Detlef Kindler K.-W.-Koog GmbH Andy Oldroyd Oldbaum Services Ltd. DOWNVInD EU-Project FINO BMU-Project Title Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 1
Motivation Undisturbed wind measurements offshore North Sea research platforms FINO-1 & -3 Assessment of a wind LiDAR system offshore on FINO-1 Investigation of the distorted wind flow by the met. mast structure on the FINO-1 platform using a wind LiDAR Application to future measurements on FINO-3 Outline Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 2
Wind speed measurements offshore masts wind statistic, speed and direction wind speed profile energy yield analysis High quality data at all heights for all wind directions Attention: wind flow distortion by mast structure itself (in certain wind directions) Motivation Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 3
FINO 3 (2008) FINO 1 (2003) & Alpha Ventus German offshore test site (2008) FINO Research Platforms Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 4
+103 + 103 SKN m + +105 m FINO 1 FINO 3 +20,5m + SKN m +26 m + +22 21,5 m m SKN=NW +4.6 m SKN -28m - SKN m -23-23 mm -58m SKN -50 m Layout FINO 1 vs. FINO 3 Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 5
B 6 WS, WD Top 11 WS 10 WS, WD 6 a 5 T, F WS A 10 a 9 T, P, F, N, dt WS C 4 WS, WD 8 WS, WD 3 WS 7 WS T, P, F, N, S, dt 2 Container Main Deck D Pile 1 WS Measurement Levels Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 6
Top 11 10 10 a WS/WD SONIC 10 Hz A 9 8 WD Vane 1Hz 7 B 6 6 a 5 C 4 3 2 Container D Pfahl Hauptdeck 1 WS Cup 1 Hz Wind Sensors Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 7
Square Mast Base Disturbed Sectors B A 345 A 015 W N S E 285 B 030 075 B A A B 255 240 105 cup on mast top 195 A 165 cup on boom 60m FINO-1 Wind Flow Distortion Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 8
103 m 81 m Comparison top level & 2 boom levels Cups, disturbed LiDAR, undisturbed Level3 Level 2 61 m Level 1 FINO-1 Wind LiDAR Assessment Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 9
Undisturbed top sectors Height: 103 (78) m WS range: LiDAR 2 to 23 m/s Slope: m = 0.97 Regr. coefficient: Cup R 2 = 0.99 WS Regression 103 m (Top) Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 10
Analysis Sector 15-75, 105-165, 195-255, 295-345 30 to 90 and 180 to 240 103 (78) m 1st Period, 4 weeks 81 (56) m 61 (36) m 10-min-avg. values 1965 / / Slope "m" 0.97 / / Regr. Coeff "R 2 " 0.99 / / 2nd Period, 14 weeks 103 (78) m 81 (56) m 61 (36) m 10-min-avg. values 6005 2589 2749 Slope "m" 0.98 0,97 0,98 Regr. Coeff "R 2 " 0.99 0.99 1,00 Regression Results Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 11
Use regression results from undisturbed sectors to correct LiDAR wind speeds Use corrected LiDAR wind speeds as undisturbed equivalent of cup wind speeds for all wind directions, i.e. as well in disturbed sectors Derive correction factors in WD ranges, i.e. as well in disturbed sectors to be applied to the full time series Correction Procedure Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 12
Top WS corrections 103 m Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 13
Boom WS Corrections 81 m Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 14
FINO 3: Triangular Base FINO 1: Square Base Main Wind Direction SW Met Mast Base Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 15
Main Wind Direction SW N W E S Messmast Messmast Main Deck Heli Deck FINO 3 Mast & Boom Orientation Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 16
70 m - Level 7 N Cup W E S Cup Cup Pure Wind Speed Level Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 17
Cup vs. LiDAR comparison campaign on FINO1 LiDAR proved high quality and good availability allowed an analysis of mast disturbance effects Heavy disturbances of wind flow from mast structure need pre-cautions - slim mast structure - triangular mast shape three boom directions - sufficient boom length Consequences for FINO3 triangular shaped, slim met. mast layout final boom layout still to be defined Outlook: LiDAR as stand alone offshore wind monitoring tool on smaller support structures (maybe floating ) on existing offshore structures e.g. like oil & gas platforms research project Summary Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 18
The End Kaiser-Wilhelm-Koog GmbH EOW 2007 Berlin Slide No. 19 Thanks