Wind farm power optimization through wake steering

Michael F Howland; Sanjiva K Lele; John O Dabiri

doi:10.1073/pnas.1903680116

Wind farm power optimization through wake steering

Proc Natl Acad Sci U S A. 2019 Jul 16;116(29):14495-14500. doi: 10.1073/pnas.1903680116. Epub 2019 Jul 1.

Authors

Michael F Howland¹, Sanjiva K Lele^{1

2}, John O Dabiri^{3

4}

Affiliations

¹ Department of Mechanical Engineering, Stanford University, Stanford, CA 94305.
² Department of Astronautics and Aeronautics, Stanford University, Stanford, CA 94305.
³ Department of Mechanical Engineering, Stanford University, Stanford, CA 94305; jodabiri@stanford.edu.
⁴ Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305.

Abstract

Global power production increasingly relies on wind farms to supply low-carbon energy. The recent Intergovernmental Panel on Climate Change (IPCC) Special Report predicted that renewable energy production must leap from [Formula: see text] of the global energy mix in 2018 to [Formula: see text] by 2050 to keep global temperatures from rising 1.5°C above preindustrial levels. This increase requires reliable, low-cost energy production. However, wind turbines are often placed in close proximity within wind farms due to land and transmission line constraints, which results in wind farm efficiency degradation of up to [Formula: see text] for wind directions aligned with columns of turbines. To increase wind farm power production, we developed a wake steering control scheme. This approach maximizes the power of a wind farm through yaw misalignment that deflects wakes away from downstream turbines. Optimization was performed with site-specific analytic gradient ascent relying on historical operational data. The protocol was tested in an operational wind farm in Alberta, Canada, resulting in statistically significant ([Formula: see text]) power increases of 7-[Formula: see text] for wind speeds near the site average and wind directions which occur during less than [Formula: see text] of nocturnal operation and 28-[Formula: see text] for low wind speeds in the same wind directions. Wake steering also decreased the variability in the power production of the wind farm by up to [Formula: see text] Although the resulting gains in annual energy production were insignificant at this farm, these statistically significant wake steering results demonstrate the potential to increase the efficiency and predictability of power production through the reduction of wake losses.

Keywords: data science; turbulence; wind energy.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.