Wind Shear and Wind Veer Effects on Wind Turbines

Lundquist, Julie K.

doi:10.1007/978-3-030-05455-7_44-1

Cited by 3 publications

(2 citation statements)

References 86 publications

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“…It is usually characterized based on its core height, wind speed and wind direction. With clear links to various processes such as advection, wind shear and turbulent mixing, the LLJ core characteristics can have a series of practical implications with respect to, e.g., air quality (Wei et al, 2023;Klein et al, 2019), changes in precipitation patterns (Algarra et al, 2019;Chen et al, 2022), aviation safety (Gultepe et al, 2019;Liu et al, 2014), the potential of, and risk to, wind energy production (Lundquist, 2021;Luiz and Fiedler, 2022;Rubio et al, 2022), urban ventilation (He et al, 2022), as well as the heat spatial distribution and intensity of the UHI effect (Kallistratova and Kouznetsov, 2012;Hu et al, 2013;Ulpiani, 2021;Lin et al, 2022). The LLJ is highly relevant for meteorology because its core characteristics are associated with the turbulent mass exchange in the ABL (Blackadar, 1957).…”

Section: Introductionmentioning

confidence: 99%

The Paris Low-Level Jet During PANAME 2022 and its Impact on the Summertime Urban Heat Island

Céspedes,

Kotthaus,

Preissler

et al. 2024

Preprint

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Abstract. The Low-Level Jet (LLJ) and the Urban Heat Island (UHI) are common nocturnal phenomena in the atmospheric boundary layer. While the canopy layer UHI has been studied extensively, interactions of the LLJ and the urban atmosphere in general (and the UHI in particular) have received less attention. In the framework of the PANAME initiative in the Paris region, continuous measurements of wind speed and vertical velocity profiles were recorded with two Doppler Wind Lidars (DWL) – for the first time allowing for a detailed investigation of the summertime LLJ characteristics in the region. Jets are detected for 70 % of the examined nights, often simultaneously at an urban and a suburban site highlighting the LLJ regional spatial extent. Emerging at around sunset, the mean LLJ duration is ∼10 h, the mean wind speed is ∼9 ms−1, and the average core height is 400 m above the city. For many jets, results show signatures in the temporal evolution that indicate the inertial oscillation mechanism plays a role in the jet development: a clockwise veering of the wind direction and a rapid acceleration followed by a slower deceleration. The LLJ core induces variance in the vertical velocity (σ2w) above the urban canopy layer. It is shown that σ2w is a powerful indicator for the air temperature spatial contrasts as UHI intensity decreases exponentially with increasing σ2w and strong values only occur when σ2w is very weak. This study demonstrates how DWL observations in cities provide valuable insights into near-surface processes relevant to human and environmental health.

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Section: Introductionmentioning

confidence: 99%

The Paris Low-Level Jet During PANAME 2022 and its Impact on the Summertime Urban Heat Island

Céspedes,

Kotthaus,

Preissler

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…There have been wind veer studies, which can be categorized as follows: wind veer characteristics (Abkar et al, 2018;Bodini et al, 2019;Brugger et al, 2020;Churchfield and Sirnivas, 2018;Shu et al, 2020b), its impacts on turbine power production Gao et al, 2021;Lundquist, 2020a, 2020b;Wagner et al, 2010) and turbine wake deflection (Brugger et al, 2019;Gadde and Stevens, 2019;Howland and Dabiri, 2020;Lundquist, 2022;Narasimhan et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

An Effect of Wind Veer on Wind Turbine Performance

Tumenbayar

2022

Int. J. Renew. Energy Dev.

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An investigation was performed to identify the wind veer impact on wind turbine power performance at a wind farm located on Jeju Island, South Korea. A 2 MW wind turbine was used as a test turbine. An 80 m-tall met mast was located 220 m away from the test wind turbine and a ground lidar was installed close to the met mast. The wind veer conditions were divided into four types: veering in upper and lower rotor (VV), veering in upper and backing in lower rotor (VB), backing in upper and lower rotor (BB) and backing in upper and veering in lower rotor (BV). The frequency of the four types was identified at the wind farm. The characteristics of wind veer was analysed in terms of diurnal variation and wind speed. In addition, the power curves of the four types were compared with that under no veer condition. Also, the power deviation coefficient (PDC) derived from the power outputs was calculated to identify the effect of the four types on the turbine power performance. As a result, the frequencies of the types, VV, VB, BB and BV were 62.7 %, 4.9 %, 9.2 % and 23.1 %, respectively. The PDCs for the types VV and BV were 3.0 % and 4.2 %, respectively, meaning a power gain while those for the types VB and BB were -2.9 % and -3.9 %, respectively, meaning a power loss.

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Investigation of wind veer characteristics on complex terrain using ground-based lidar

Tumenbayar,

2023

Int. J. Renew. Energy Dev.

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The wind direction shift with height significantly influences wind turbine performance, particularly in relation to terrain conditions. In this work, wind conditions at 12 measurement heights ranging from 40 m to 200 m using a ground lidar, Windcube V2, installed on a 16 m tall building were analysed to examine the characteristics of wind veer angles in complex terrain. The measurement campaign was carried out from January 1st to December 31st, 2022, in the southeastern part of South Korea. The terrain complexity around the ground lidar system was evaluated using the ruggedness index (RIX), whose result was 14.06 percent corresponding to complex terrain. The ground lidar measurements were compared with mesoscale data, EMD-WRF South Korea, for the data accuracy check. Wind veer frequencies and wind roses were derived to identify directional shifts with height. Furthermore, diurnal, monthly, and seasonal variations of wind veer characteristics were analysed. Wind shear exponent factor (WSE) and turbulence kinetic energy (TKE) were calculated, and wind veer profiles were constructed based on these parameters. The relative errors of wind speeds were analysed for rotor equivalent wind speed (REWS) and hub height wind speed (HHWS), with REWS with wind veer correction, REWSveer, as a reference. Additionally, atmospheric stability conditions were classified using WSE and TKE, and the vertical changes in wind veering were analysed according to the stability conditions. The findings reveal lower wind speeds exhibited larger wind veer values and fluctuations. The relative errors for the REWS and the HHWS were 0.04 % and 0.20 % on average, respectively. The study demonstrates that terrain conditions significantly impacted wind veer angles at heights below 100 m, whereas the influence diminished with increasing height above 100 m. The results could be helpful for wind farm developers to make decisions on the siting as well as the hub height of wind turbines on complex terrain

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Wind Shear and Wind Veer Effects on Wind Turbines

Cited by 3 publications

References 86 publications

The Paris Low-Level Jet During PANAME 2022 and its Impact on the Summertime Urban Heat Island

The Paris Low-Level Jet During PANAME 2022 and its Impact on the Summertime Urban Heat Island

An Effect of Wind Veer on Wind Turbine Performance

Investigation of wind veer characteristics on complex terrain using ground-based lidar

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