CALIFORNIA WIND ENERGY RESOURCE MODELING AND MEASUREMENT: Measurement Program Final Report

Publication Number: CEC-500-2006-066
Publication Date: June 2006
PIER Program Area: Renewable Energy Research

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Executive Summary

None available.

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Abstract

These reports present the results of a wind resource measurement study conducted on behalf of the California Energy Commission by AWS Truewind for five focus areas in California. The objective of the Measurement Program was to collect high-quality data at heights relevant to modern wind turbines. Data was collected from four tall tower locations and seven sodar sites in California. The analysis period covered in this report is from April 2004 to July 2005. A number of important wind characteristics are presented, including mean wind speed, wind shear, prevailing wind direction, and diurnal speed distributions. Long-term speed estimates were produced for the tall tower locations and sodar locations, when appropriate, through a comparison with regional meteorological reference stations.

Keywords: Wind measurement, tall-tower, sodar, wind speed, wind shear, diurnal wind distribution

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Table of Contents

Abstract i

Preface ii

1.0 Introduction 1

2.0 Tall Tower Campaign 3

3.0 Sodar Campaign Results 10

4.0 Review of Measurement Program Results 33

Appendix 1


List of Figures

Figure 1: Overview of Focus Areas and Measurement Sites 2

Figure 2: Energy Commission Tall Tower and reference station locations 39

Figure 3: Tall Tower hourly mean wind speed distributions 41

Figure 4: Tall Tower wind roses 42

Figure 5: Tall Tower diurnal temperature and wind shear distributions 43

Figure 6: Reference station annual mean wind speeds, for Tall Tower sites 44

Figure 7: Sodar at Antelope Valley site, looking west 45

Figure 8: Sodar at Antelope Valley site, looking south 45

Figure 9: Sodar at Oak Creek site, looking north 46

Figure 10: Sodar at Oak Creek site, looking south. 46

Figure 11: Sodar at Oak Creek site, looking west 47

Figure 12: Time series of wind direction, for the Antelope Valley and Oak Creek sodars as well as Rosamond and Oak Creek towers 47

Figure 13: Antelope Valley sodar hodograph, at 50 m. 48

Figure 14: Oak Creek sodar hodograph, at 50 m. 48

Figure 15: Wind roses for the Antelope Valley sodar site and Rosamond tower, during the Antelope Valley sodar study. 49

Figure 16: Antelope Valley sodar 80 m speed and 80/50m slope, by time of day 50

Figure 17: Hourly average wind speeds for the Antelope Valley sodar and Rosamond tower at 110 m, for all speeds and directions. 50

Figure 18: Average wind speed profiles for the Antelope Valley sodar and the Rosamond tower, for all speeds and directions. 51

Figure 19: Average wind speed profiles for the Antelope Valley sodar and the Rosamond tower, for 50 m sodar speeds > 5 m/s, and wind from the SSW 51

Figure 20: Average wind speed profiles for the Antelope Valley sodar and the Rosamond tower, for 50 m sodar speeds > 5 m/s, and wind from the WSW 52

Figure 21: Average wind speed profiles for the Antelope Valley sodar and the Rosamond tower, for 50 m sodar speeds > 5 m/s, and wind from the WNW 52

Figure 22: Antelope Valley sodar vertical velocity, at 50 m (positive upward) 53

Figure 23: Comparison of hourly Antelope Valley sodar 80 m speed with the Munz Ranch 21 m speed. 53

Figure 24: Wind roses for the Oak Creek sodar and tower during the Oak Creek sodar study. 55

Figure 25: Oak Creek sodar 80 m speed and 80/50 m shear, by hour of day. 56

Figure 26: Hourly averaged sodar and tower wind speeds at 70 m for the Oak Creek sodar study. 56

Figure 27: Average wind speed profiles for the Oak Creek sodar and tower, for the Oak Creek sodar study 57

Figure 28: Average wind speed profiles for the Oak Creek sodar and tower for all directions, for 50 m sodar speeds > 5 m/s, excluding the high wind speed event of days 177-179 57

Figure 29: Average wind speed profiles at the Oak Creek tower and sodar, for WNW 50 m sodar speeds > 5 m/s, excluding the high wind speed event of days 177-179 58

Figure 30: Average wind speed profiles for the Oak Creek tower and sodar, for NNW 50 m sodar speeds > 5 m/s, excluding the high wind speed event of days 177-179 58

Figure 31: Oak Creek sodar vertical velocity, at 50 m (positive upward) 59

Figure 32: Profiles of Oak Creek flow inclination by wind direction sector. 59

Figure 33: Time-height section of the Oak Creek sodar wind profile during the shift in flow regimes from S to NW on day 175. 60

Figure 34: Geyserville tower site 62

Figure 35: Map showing locations of Mayacamas sodar and tower sites 63

Figure 36: Mayacamas sodar site, looking east 64

Figure 37: Mayacamas sodar site, looking south 64

Figure 38: Calpine sodar site, looking east 65

Figure 39: Calpine sodar site, looking south 65

Figure 40: Calpine sodar site, looking west 66

Figure 41: Mayacamas sodar hodograph, at 50 m. 66

Figure 42: Calpine sodar hodograph, at 50 m. 67

Figure 43: Wind roses for Mayacamas sodar and Geyserville tower during the Mayacamas sodar study. 69

Figure 44: Hourly average wind speeds for the Mayacamas sodar and Geyserville tower at 60 m, for all speeds and directions. 70

Figure 45: Hourly average wind speeds for the Mayacamas sodar and Geyserville tower at 60 m, for all directions, and 50 m sodar speeds > 5 m/s. 70

Figure 46: Mayacamas sodar 80 m speed and 80/50 m shear, by hour of day. 71

Figure 47: Average wind speed profiles for the Mayacamas sodar and the Geyserville tower, for all speeds and directions. 72

Figure 48: Average wind speed profiles for the Mayacamas sodar and the Geyserville tower, for all directions, and 50 m sodar speeds > 5 m/s. 73

Figure 49: Average wind speed profiles for the Mayacamas sodar and the Geyserville tower, for 50 m sodar speeds > 5 m/s, and wind from the NW 73

Figure 50: Average wind speed profiles for the Mayacamas sodar and the Geyserville tower, for 50 m sodar speeds > 5 m/s, and wind from the NE 74

Figure 51: Average wind speed profiles for the Mayacamas sodar and the Geyserville tower, for 50 m sodar speeds > 5 m/s, and wind from the SW 74

Figure 52: Mayacamas sodar vertical velocity, 50 m (positive upward) 75

Figure 53: Scatter plot of Mayacamas sodar 80 m wind speeds compared to Calpine Unit 17 met stations wind speeds, during the Mayacamas sodar study 75

Figure 54: Wind roses for Calpine sodar site and Geyserville tower during the Calpine sodar study. 77

Figure 55: Hourly averaged Calpine sodar and Geyserville tower wind speeds at 60 m, during the Calpine sodar study. 78

Figure 56: Average wind speed profiles for the Calpine sodar and Geyserville tower. 78

Figure 57: Average Calpine sodar, Geyserville tower, Calpine Unit 17 speed profiles, for 50 m sodar speeds > 5 m/s. 79

Figure 58: Average Calpine sodar, Geyserville tower, and Calpine Unit 17 wind speed profiles, for 50 m sodar wind speed > 5 m/s, in the E direction sector. 79

Figure 59: Average Calpine sodar, Geyserville tower, and Calpine Unit 17 wind speed profiles, for 50 m sodar wind speeds > 5 m/s, with NE winds 80

Figure 60: Calpine sodar mean 80 m speed and 80/60 m shear, by hour of day 80

Figure 61: Calpine sodar vertical velocity (positive upward) 81

Figure 62: Scatter plot of Calpine sodar 80 m wind speeds with Calpine Unit 17 wind speeds during the Calpine sodar study period 81

Figure 63: Mojave sodar site, looking west 82

Figure 64: Mojave sodar site, looking south 82

Figure 65: Wind rose for the Mojave sodar. 84

Figure 66: Mojave sodar mean 80 m speed and 80/50 m shear, by hour of day 84

Figure 67: Mojave sodar hodographs, for days 220 to 260. 85

Figure 68: Average wind speed profiles for the Mojave sodar, for all speeds and directions. 85

Figure 69: Average wind speed profiles for the Mojave sodar, for all directions, with 50 m speeds > 5 m/s. 86

Figure 70: Average wind speed profiles for the Mojave sodar, for 50 m speeds > 5 m/s, and wind from the SW 86

Figure 71: Average wind speed profiles for the Mojave sodar, for 50 m speeds > 5 m/s, and wind from the W 87

Figure 72: Mojave sodar vertical velocity rose (positive upward) 87

Figure 73: San Gorgonio sodar site, looking west 88

Figure 74: San Gorgonio sodar site, looking south 88

Figure 75: San Gorgonio sodar site, looking north 89

Figure 76: San Gorgonio mean 80 m speed and 80/50 m shear, by hour of day 91

Figure 77: Wind rose for San Gorgonio sodar study. 91

Figure 78: Average wind speed profiles for the San Gorgonio sodar, for all speeds and directions. 92

Figure 79: Average wind speed profiles for the San Gorgonio sodar, for all directions, and 50 m sodar speeds > 5 m/s 92

Figure 80: Average wind speed profiles for the San Gorgonio sodar, for 50 m sodar speeds > 5 m/s, and wind from the W 93

Figure 81: Average wind speed profiles for the San Gorgonio sodar, for 50 m sodar speeds > 5 m/s, and wind from the NW 93

Figure 82: Time series of temperature and San Gorgonio sodar 80 m wind speed. 94

Figure 83: Shasta sodar site, looking east 94

Figure 84: Time-height image of wind speed during the Weed Airport sodar study. 95

Figure 85: Wind rose for the Shasta sodar study at 50 m. 96

Figure 86: Hourly-averaged wind vectors at 50 m for an undisturbed period (days 113 to 120) at the Weed Airport. 97

Figure 87: Average wind speed profile during the Shasta sodar study period, for all speeds and directions. 98

Figure 88: Average wind speed profile during the Shasta sodar study period, for 50 m sodar speeds > 5 m/s 98

Figure 89: Average wind speed profile during the Shasta sodar study period, for 50 m sodar speeds > 5 m/s and wind from the SE 99

Figure 90: Average wind speed profile during the Shasta sodar study period, for 50 m sodar speeds > 5 m/s and wind from the S 99

Figure 91: Shasta sodar mean 80 m speed and 80/50 m shear, by hour of day 100

Figure 92: Meteorological station operated by the California Department of Water Resources, located at the Weed, CA airport 101

Figure 93: Comparison of sodar 80 m daily mean speeds (m/s) with the Weed Airport met station speeds 102


List of Tables

Table 1: Locations and dates of the Oak Creek and Antelope Valley sodar studies. 12

Table 2: Mean statistics for coincident data from the Antelope Valley sodar and Rosamond tower, for 50 m sodar speeds > 5 m/s. 13

Table 3: Profile statistics by wind direction for the Antelope Valley sodar and Rosamond tower, for 50 m sodar speeds >5 m/s 14

Table 4: Profile statistics by wind direction for the Antelope Valley sodar site and Rosamond tower, for 50 m sodar speeds >8 m/s 14

Table 5: Antelope Valley sodar wind speeds compared to the 21 m speeds from the Munz Ranch mast. 15

Table 6: Mean statistics for coincident data from the Oak Creek sodar and tower. 15

Table 7: Mean statistics for coincident data from the Oak Creek sodar and tower, excluding the high wind event of days 177-179. 16

Table 8: Profile statistics by wind direction sector for the Oak Creek site, with 50 m sodar speeds >5 m/s 16

Table 9: Profile statistics by wind direction sector for the Oak Creek site, for 50 m sodar speeds >8 m/s 17

Table 10: Locations and dates of the Mayacamas and Calpine sodar studies. 19

Table 11: Mean statistics for coincident data from the Mayacamas sodar and Geyserville tower, for 50 m sodar speeds > 5 m/s. 20

Table 12: Profile statistics by wind direction sector at the Mayacamas sodar site, for 50 m sodar speeds >5 m/s 20

Table 13: Profile statistics by wind direction sector at the Mayacamas sodar site, for 50 m sodar speeds >8 m/s 21

Table 14: Mean statistics for coincident data from the Calpine sodar site and Geyserville tower, for all speeds and 50 m sodar speeds > 5 m/s. 22

Table 15: Profile statistics by direction for the Calpine sodar site and Geyserville tower, for 50 m sodar speeds >5 m/s 22

Table 16: Location and dates of the Mojave sodar study 24

Table 17: Mean statistics for the Mojave sodar study by wind direction sector 24

Table 18: Mean statistics for the Mojave sodar study, for 50 m sodar speeds > 5 m/s, by wind direction sector. 25

Table 19: Mean statistics for the Mojave sodar study by direction, for 50 m sodar speeds > 8 m/s. 25

Table 20: Location and dates of the San Gorgonio sodar study 26

Table 21: Mean statistics for the San Gorgonio sodar study, by wind direction sector. 27

Table 22: Mean statistics for the San Gorgonio sodar study by direction, for 50 m sodar speeds > 5 m/s. 27

Table 23: Mean statistics for the San Gorgonio sodar study by direction, for 50 m sodar speeds > 8 m/s 28

Table 24: Location and dates of the Shasta Valley sodar study 29

Table 25: Shasta sodar mean speeds (“U”) and shear parameters (m) at specified heights by direction 30

Table 26: Shasta sodar mean speeds (“U”) and shear parameters at specified heights (m) by wind direction sector, for 50 m sodar speeds > 5 m/s 30

Table 27: Shasta sodar mean speeds (“U”) and shear parameters at specified heights (m) by direction, for 50 m speeds > 8 m/s 30

Table 28: Tall Tower anemometer information 34

Table 29: Tall Tower data summary 36

Table 30: Tall Tower monthly mean wind speeds 36

Table 31: Tall Tower mean wind shear at top monitoring height, as a function of wind speed 37

Table 32: Tall Tower reference site summary 38

Table 33: Tall Tower reference site regression summary 38

Table 34: Tall Tower long-term wind speed projections 38

Table 35: Locations and types of sensors on the Rosamond and Oak Creek towers. 44

Table 36: Mean statistics at specified heights (m) for the Antelope Valley sodar study, by speed (m/s). 54

Table 37: Oak Creek sodar mean speeds (“U”) and shear parameters at specified heights (m) by speed (m/s). 61

Table 38: Locations and types of sensors on the Geyserville tower. 61

Table 39: Mayacamas sodar and Geyserville tower mean speeds (“U”, m/s) and shear parameters for designated 50 m sodar speed intervals, during the Mayacamas sodar study. 68

Table 40: Calpine sodar and Geyserville tower mean speed (“U”, m/s) and shear parameters for designated 50 m sodar speed intervals, during the Calpine sodar study period 76

Table 41: Mojave mean speeds and shear parameters by 50 m wind speed. 83

Table 42: Mean speeds and shear parameters at San Gorgonio by 50 m wind speed. 90

Table 43: Shasta sodar mean speeds (“U”) and shear parameters at specified heights (m) by 50 m speed bin. 103