Measurement geometry

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WT 8091/10 (extract from WT 8090/10)

Page 1 of 2

Summary of results of the noise emission measurement, in accordance with IEC 61400-11, of a WTGS of the type

REpower 3.4M 104 Customer:

Date of Order:

Galmsbüll (Turbine No. 300.003)

Site:

REpower Systems AG Albert-Betz-Str. 1 24783 Osterrönfeld Germany

Contractor:

WINDTEST Kaiser-Wilhelm-Koog GmbH Sommerdeich 14 b 25709 Kaiser-Wilhelm-Koog Germany

2010-11-09

Order No.:

4285 09 05754 252

Extracts from this report may only be reproduced with the written permission of WINDTEST Kaiser-Wilhelm-Koog GmbH. This report consists of 2 pages in total.

Wind Turbine Technical Data: Type: ........................................................................REpower 3.4M 104 Manufacturer:......................................................REpower Systems AG Turbine serial number:...............................................................300.003 Rated power:............................................................................ 3370 kW Power control: .................................................................................pitch Tower type: ..................................................................... tubular/conical Rotor manufacturer:...............................................PowerBlades GmbH Rotor blade type:.........................................................................RE50.8 Rotor blade serial number: .......................................... 0011/0012/0013 Rotor diameter: .............................................................................104 m Rotor blade pitch angle (degrees): ............................................variabel Number of rotor blades: ........................................................................3 Rotor speed(s) (or range): ............................................. 6,9 - 13,8 min-1 Gearbox manufacturer:..............................................................Eickhoff Gearbox type: .....................................EBN 2525 A03R01A/G53645XA Gearbox serial numbers: ..............................................................23616 Generator manufacturer: .......................................................... Winergy Generator type: ....................................................... JFRA-630MR-06A1 Generator serial number: .........................................................5147738 Generator speed(s) (or range):...................................... 600-1200 min-1 Generator rated power:............................................................ 3589 kW These data do not replace the corresponding manufacturer’s certificate.

REpower Dokumenten-Nummer

Rev.

D-3.1-VM.SM.03-D

A

Freigabe

Datum

S. Bigalke

2010-05-11

-EN

Measurement geometry: Hub height above ground:.......................................................... 80 m Measurement distance R0:...................................................... 120 m Height of microphone hA: ............................................................ 0 m Distance rotor centre to tower axis d: .................................... 4,23 m

Measurement conditions: Measurement date(s): ..................................................... 2010-04-01 Range of wind speed at 10m height, 1-min average WS10m:..................................................5,5 - 11,0 m/s Wind direction: ..........................................................................WSW Range of power, 1-min-average Pw el:...................... 2866 - 3413 kW Air pressure pLuft:...................................................... 998 - 1002 hPa Air temperature TLuft: ...................................................... 4,2 - 7,1 °C Turbulence intensity: ..............................................................14,1 %

Power curve: From report: DEWI W-PV 09-003.1.A Testing Auth.: DEWI GmbH Measurement Period: 2009-05-20 - 2009-07-13 WS (m/s) 2,07 2,49 3,03 3,46 4,02 4,52 5,00 5,53 6,04 6,49 7,01

Power (kW) -4,95 -5,28 0,23 24,05 89,71 150,98 239,95 370,83 487,01 626,83 798,07

WS (m/s) 7,51 8,00 8,49 9,01 9,47 10,00 10,46 11,01 11,50 12,02 12,51

Power (kW) WS (m/s) 1024,74 1209,62 1474,97 1814,70 2056,48 2303,86 2515,73 2864,85 3055,63 3205,83 3300,00

Power (kW)

13,01 13,50 14,00 14,48 15,05 15,50 15,98 16,55 16,94 17,52 18,00

3353,96 3396,26 3408,87 3432,91 3429,10 3428,33 3430,79 3426,74 3424,61 3427,48 3421,64

Determination of the sound power level: WS10m

6

7

8

9

10

1402

2186

2915

3302

3407

-

105,0

103,9

103,1

103,0

-

1,2

1,2

1,1

1,1

[m/s] PW el [kW] LWA [dB] UC [dB]

WT 8091/10 (extract from WT8090/10)

Page 2 of 2

Summary of results of the noise emission measurement, in accordance with IEC 6140061400-11, of a WTGS of the type REpower 3.4 3.4M 104

Recalculation of LWA for different hub heights in dB(A) (WS at a height of 10 m) **: Hub height [m]

LWA (6 m/s)

LWA (7 m/s)

LWA (8 m/s)

LWA (9 m/s)

LWA (10 m/s)

78,0

-

105,1

103,9

103,2

103,1

96,5

-

104,8

103,9

102,8

102,9

100,0

-

104,7

103,9

102,8

102,9

**

A direct recalculation of the tonality is not possible, as other acoustic effects may arise due to the different length of the tower.

Third octave sound power spectrum in dB(A) for the wind speed in 10 m height corresponding to the maximum sound power level given on page 1: 1/3 octave freq. [Hz] LWA (7,0 m/s) 1/3 octave freq. [Hz] LWA (7,0 m/s)

50

63

80

100

125

160

200

250

315

400

500

630

76,1

79,0

81,5

88,1

89,1

88,7

90,8

93,3

94,4

94,6

96,0

95,3

800

1000

1250

1600

2000

2500

3150

4000

5000

6300

8000

10000

95,6

94,9

93,5

92,6

89,7

87,3

84,8

81,1

76,6

70,0

63,6

58,2

Tonality according to IEC 61400-11/Ed.2: Representative FFT - Spectra (left 8 m/s and right 10 m/s at a height of 10 m):

WS in 10 m height [m/s]

6,0

7,0

8,0

9,0

10,0

Freq. of most prevalent tone, f [Hz]

-

112

112

112

112

Tonality, ∆Lk [dB]

-

-3,45

-6,79

-2,77

-2,40

Audibility, ∆La,k [dB]

-

-1,44

-4,78

-0,76

-0,39

Remarks: For lack of values at the 6 m/s bin, it was not possible to perform the analysis for this bin. Checked:

________________________ Dipl.-Ing. K. Buchmann Head of Department Acoustics & Inspections

Kaiser-Wilhelm-Koog, 2010-06-01

Engineer:

________________________ Dipl.-Ing. J. Dedert