Abstract
In order to study the effect of vertical staggering in large wind farms, large eddy simulations (LES) of large wind farms with a regular turbine layout aligned with the given wind direction were conducted. In the simulations, we varied the hub heights of consecutive downstream rows to create vertically staggered wind farms. We analysed the effect of streamwise and spanwise turbine spacing, the wind farm layout, the turbine rotor diameter, and hub height difference between consecutive downstream turbine rows on the average power output. We find that vertical staggering significantly increases the power production in the entrance region of large wind farms and is more effective when the streamwise turbine spacing and turbine diameter are smaller. Surprisingly, vertical staggering does not significantly improve the power production in the fully developed regime of the wind farm. The reason is that the downward vertical kinetic energy flux, which brings high velocity fluid from above the wind farm towards the hub height plane, does not increase due to vertical staggering. Thus, the shorter wind turbines are effectively sheltered from the atmospheric flow above the wind farm that supplies the energy, which limits the benefit of vertical staggering. In some cases, a vertically staggered wind farm even produced less power than the corresponding non vertically staggered reference wind farm. In such cases, the production of shorter turbines is significantly negatively impacted while the production of the taller turbine is only increased marginally.
| Original language | English |
|---|---|
| Pages (from-to) | 189-204 |
| Number of pages | 16 |
| Journal | Wind energy |
| Volume | 22 |
| Issue number | 2 |
| Early online date | 12 Oct 2018 |
| DOIs | |
| Publication status | Published - 1 Feb 2019 |
Keywords
- atmospheric boundary layer
- large eddy simulation
- power production
- turbulence
- vertically staggered wind farm
- wake model
Cite this
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Large eddy simulations of the effect of vertical staggering in large wind farms. / Zhang, Mengqi; Arendshorst, Mark G.; Stevens, Richard J. A. M. (Corresponding Author).
In: Wind energy, Vol. 22, No. 2, 01.02.2019, p. 189-204.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Large eddy simulations of the effect of vertical staggering in large wind farms
AU - Zhang, Mengqi
AU - Arendshorst, Mark G.
AU - Stevens, Richard J. A. M.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - In order to study the effect of vertical staggering in large wind farms, large eddy simulations (LES) of large wind farms with a regular turbine layout aligned with the given wind direction were conducted. In the simulations, we varied the hub heights of consecutive downstream rows to create vertically staggered wind farms. We analysed the effect of streamwise and spanwise turbine spacing, the wind farm layout, the turbine rotor diameter, and hub height difference between consecutive downstream turbine rows on the average power output. We find that vertical staggering significantly increases the power production in the entrance region of large wind farms and is more effective when the streamwise turbine spacing and turbine diameter are smaller. Surprisingly, vertical staggering does not significantly improve the power production in the fully developed regime of the wind farm. The reason is that the downward vertical kinetic energy flux, which brings high velocity fluid from above the wind farm towards the hub height plane, does not increase due to vertical staggering. Thus, the shorter wind turbines are effectively sheltered from the atmospheric flow above the wind farm that supplies the energy, which limits the benefit of vertical staggering. In some cases, a vertically staggered wind farm even produced less power than the corresponding non vertically staggered reference wind farm. In such cases, the production of shorter turbines is significantly negatively impacted while the production of the taller turbine is only increased marginally.
AB - In order to study the effect of vertical staggering in large wind farms, large eddy simulations (LES) of large wind farms with a regular turbine layout aligned with the given wind direction were conducted. In the simulations, we varied the hub heights of consecutive downstream rows to create vertically staggered wind farms. We analysed the effect of streamwise and spanwise turbine spacing, the wind farm layout, the turbine rotor diameter, and hub height difference between consecutive downstream turbine rows on the average power output. We find that vertical staggering significantly increases the power production in the entrance region of large wind farms and is more effective when the streamwise turbine spacing and turbine diameter are smaller. Surprisingly, vertical staggering does not significantly improve the power production in the fully developed regime of the wind farm. The reason is that the downward vertical kinetic energy flux, which brings high velocity fluid from above the wind farm towards the hub height plane, does not increase due to vertical staggering. Thus, the shorter wind turbines are effectively sheltered from the atmospheric flow above the wind farm that supplies the energy, which limits the benefit of vertical staggering. In some cases, a vertically staggered wind farm even produced less power than the corresponding non vertically staggered reference wind farm. In such cases, the production of shorter turbines is significantly negatively impacted while the production of the taller turbine is only increased marginally.
KW - atmospheric boundary layer
KW - large eddy simulation
KW - power production
KW - turbulence
KW - vertically staggered wind farm
KW - wake model
UR - http://www.scopus.com/inward/record.url?scp=85049672695&partnerID=8YFLogxK
U2 - 10.1002/we.2278
DO - 10.1002/we.2278
M3 - Article
VL - 22
SP - 189
EP - 204
JO - Wind energy
JF - Wind energy
SN - 1095-4244
IS - 2
ER -