Introduction 2
© EMD International • www.emd.dk • windPRO 4.1 • September 2024
8b.1 Introduction
Wind farms must comply with noise regulations, and two approaches are being used to ensure compliant noise
immission levels at noise receptors emitted by wind turbines: control the turbine position (Cao et al. 2020) or
control the turbine operation modes (Nyborg et al. 2023). When wind turbines are already installed or the planned
positions are decided upon, the remaining option is, therefore, curtailing the operation modes of the turbines.
The curtailment of wind turbine modes comes with reduced noise emission but also reduced energy production
(Steurer et al. 2017). The purpose of noise curtailment optimization in the context of wind farm planning is to
satisfy acoustic constraints while maximizing the usual benefits, e.g., energy production or profit.
The Noise Curtailment Optimizer (NCO) adds such functionality to the Optimizer module in windPRO to the
Layout Optimizer. The objective of the NCO is to suggest a curtailment strategy for wind farms to comply with
noise receptor thresholds around the wind farm with the lowest production loss possible. If a noise curtailment
is insufficient to comply with defined noise regulations, the tool can also propose to shut turbines down for
specific conditions as a last resort.
The NCO facility in windPRO was developed as part of the Decowind project, supported by the Danish Innovation
Fund.
8b.1.1 Noise Curtailment vs. Layout Optimizer
The Noise Curtailment Optimizer is designed to resemble the Layout optimizer, and a lot of the structure of the
optimizer will look and feel similar. In both cases the objective is to maximize production output of a wind farm,
but the degrees of freedom are different. The Layout Optimizer reaches its objective by moving the turbines
within a set of constraints, while the NCO does the same through changing the operation mode on the turbines.
The constraints of the NCO are controlled by the noise code it must comply with and the possibilities the turbine
type offers. For these reasons, the GUI must diverge from that of the Layout Optimizer as described in the
following. The result of the NCO is not a new layout but a Noise Curtailment Matrix for each turbine.
8b.1.2 The GUI tree-structure
The GUI of the Noise Curtailment Optimizer uses a tree structure like that of the Layout Optimizer with three
levels: Site, Layout and Strategy (Figure 1).
Figure 1: The three hierarchy levels of the GUI tree: Site, Layout, and Strategy.
When the NCO is opened for the first time, a first Site will be available and set with default settings for the country
of the project. The optimizer allows creating several sites, where each site can contain several layouts, and a
layout can have several strategies. Each hierarchy level can be expanded or collapsed and if highlighted, the
options for the level become visible to the right.
New levels can be added, deleted or copied. Sites can be cloned by right-clicking on the Site level: