Title: Loads assessment of a fixed-bottom offshore wind farm with wake steering

Abstract

Wake steering via deliberate yaw offset is an emerging wind farm control technique that has the potential to mitigate wake losses and further increase wind farm energy yield. The loads impact of this technique has been studied, but there is limited insight into wind-farm-wide impacts of wake steering. Understanding such impacts is crucial to determining the feasibility of using wake steering in commercial wind farms. To that end, this work investigates the impacts of wake steering on the loads of all turbine components across all turbines in a wind farm operating under a broad set of inflow conditions, including inflow velocity, shear exponent, turbulence class, and inflow angle. This was done by performing FAST.Farm simulations of a 12-turbine wind farm array, excerpted from a larger hypothetical wind farm. The International Energy Agency Wind 15-MW reference wind turbine was modeled atop a monopile substructure, an open-source model that closely approximates the properties of similar commercial options. Wake steering was included via yaw offsets that were computed using an offline optimization with the National Renewable Energy Laboratory tool FLORIS. For each inflow case, the 12-turbine array was simulated with and without wake steering. Results were compared in terms of time-averaged means, standardmore » deviations, ultimate loads, and damage-equivalent loads. The findings show that because wake steering is generally applied at rated wind speeds and below, it is unlikely to drive ultimate loads. For fatigue loads, wake steering does increase the overall fatigue accumulation for some load channels, such as blade-root and shaft bending. This is to be expected when overall power yield increases but may cause the damage accumulation to be more uniform throughout the array. The significance of the added fatigue loading is dependent on how frequent wake steering is utilized in the overall set of inflow conditions across the wind rose.« less

Authors:

Shaler, Kelsey  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-7563-3377"

Jonkman, Jason  ^[1];

• Search DOE PAGES for author "Jonkman, Jason"
• Search DOE PAGES for ORCID "0000-0003-2990-7362"

Barter, Garrett E.  ^[1];

• Search DOE PAGES for author "Barter, Garrett E."
• Search DOE PAGES for ORCID "0000-0001-7757-8853"

Kreeft, Jasper J. ^[2]; Muller, Jelle P. ^[2]

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+ Show Author Affiliations

1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
2. Shell Global Solutions International B.V., The Hague (Netherlands)

Publication Date:

Wed Jul 20 00:00:00 EDT 2022

Research Org.:

National Renewable Energy Lab. (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE); Shell Global Solutions International B.V.

OSTI Identifier:

1881297

Report Number(s):

NREL/JA-5000-81621
Journal ID: ISSN 1095-4244; MainId:82394;UUID:bc8ce9c7-c4a2-4289-b0df-aeec0b575baf;MainAdminID:64299

Grant/Contract Number:  

AC36-08GO28308

Resource Type:

Accepted Manuscript

Journal Name:

Wind Energy

Additional Journal Information:

Journal Volume: 25; Journal Issue: 9; Journal ID: ISSN 1095-4244

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

17 WIND ENERGY; FAST.Farm; turbine structural loads; turbine wakes; wake steering; wind farm