Effects of wind shear and turbulence on wind turbine power curves

Conference · Sat Sep 01 04:00:00 EDT 1990

OSTI ID:6348447

Elliott, D L ^[1]; Cadogan, J B ^[2]

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1. Pacific Northwest Lab., Richland, WA (USA)
2. USDOE, Washington, DC (USA)

It is a common practice to use wind speeds at hub height in determining wind turbine power curves. Although the possible influence of other variables (sub as turbulence and wind shear) is generally neglected in power curve measurements, we discovered the importance of other variables in an analysis of power curves for three 2.5 MW wind turbines. When the power curves were stratified by turbulence intensity. Such a large sensitivity to turbulence was not expected, and further analyses were conducted to determine if other factors accompanying the change in turbulence level could cause or contribute to the observed sensitivity of the power curves to turbulence. In summary, the sensitivity of the observed power curves was largely due to two factors: (1) an actual sensitivity to turbulence in determining the power curve and (2) the deviation of the disk-averaged velocity from the hub-height velocity under low turbulence conditions that were most prevalent at the site. An examination of the wind shear profiles over the height of the rotor disk revealed that low turbulence conditions were characterized by strong shear in the lower half of the rotor disk and weak or negative shear in the upper half. Implications of this analysis are that significant errors in power curve measurements can result if the effects of wind shear and turbulence are ignored. 7 refs., 6 figs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• Sponsoring Organization: DOE/CE
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6348447
• Report Number(s): PNL-SA-18354; CONF-900989--2; ON: DE91004072
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
170602* -- Wind Energy Engineering-- Turbine Design & Operation
170604 -- Wind Energy Engineering-- Site Characteristics
DYNAMIC LOADS
ENERGY SOURCES
MACHINERY
MEASURING METHODS
POWER
RENEWABLE ENERGY SOURCES
SHEAR
SITE CHARACTERIZATION
TURBINES
TURBOMACHINERY
TURBULENCE
WIND LOADS
WIND POWER
WIND TURBINES