Introduction

The more capacity of wind power that is commissioned and the larger wind farms grow, the more relevant the integration of intermittent wind power into the power system becomes. In the future, a Wind Farm (WF) will need to act more like a conventional power plant, i.e. complying to stricter grid code requirements and providing ancillary services to ensure safe and reliable operation of the power system. Furthermore, the role of wind power in the electricity markets will likely change, increasingly exposing WFs to the volatility of wholesale electricity prices (Hu et al., 2018). The traditional primal objective of maximising the Annual Energy Production (AEP) is expected to shift to maximising the overall profit instead.

Improved and more coordinated Wind Farm Control (WFC) has the potential to create the flexibility for WFs to participate in electricity markets to a larger extent than today. Balancing power production, load reduction and ancillary service provision will be necessary to maximise WF revenue in the future, while supporting the local grid. For example, curtailing the power generation during periods with low electricity prices, can provide incentives to follow secondary farm control objectives such as reducing structural loads or noise. This can be accomplished through Wind Farm Flow Control (WFFC), where wakes induced by upwind turbines are manipulated to reduce the impact on downwind turbines.

In this way, WFC, in its broadest sense, means the coordinated operation of the different wind turbines within a wind farm to serve a common goal. Within this paper, WFFC refers to the coordination of the actions of individual turbines in a farm for the purpose of improving inter-turbine aerodynamic interaction, to better the overall farm power production and/or reduce or distribute the structural loading among wind turbines. As such, WFFC forms part of the overall WFC strategy along with ancillary service provision, power quality management among other control modes.

In 2019, the European research project FarmConners <https://www.windfarmcontrol.info/>`_ was started with the main goal of providing an overview of the state of the art in wind farm control, identifying consensus of research findings, data sets and best practices, providing a summary of the main research challenges, and establishing a road map on how to address these challenges. One of the challenges identified to the widespread adoption of WFFC was evidence of the positive economic impact that it offers. As such, as part of the FarmConners project, a number of market scenarios have been developed as showcases to allow researchers to evaluate their WFFC strategies against a common baseline to demonstrate the potential benefits of WFFC. This paper introduces these showcases, detailing how they have been developed.

The TotalControl Reference Wind Power Plant (TC-RWP) has been chosen as an example of a large wind farm which may benefit the most from altering their operation based on the electricity markets.

The focus of the showcases lies on the operational phase, i.e. the influence of auction prices and practices as well as the design phase and commissioning are disregarded. The showcases are based on a time series of weather simulations and estimated electricity prices for 2020 and 2030 generated using the DTU Balancing Tool Chain. The weather simulations for the chosen location of the TC-RWP are run using data from 2012. The North Sea region is included in the energy systems modelling, and hourly day-ahead prices in the relevant Danish price region (DK1) are obtained. These market prices are used as fixed inputs for the analysed wind farm in the showcases. The 2020 and 2030 scenarios are both based on the same weather data but are coupled with different energy systems representing the composition in 2020 and 2030 (electric loads, CO2 price, installed generation capacities, etc.).

The showcases consist of three sets: 1) High electricity prices, 2) Low electricity prices, 3) Operation driven by the system operator. Depending on the showcase set, income, reference tracking and load alleviation will be used as performance indicators and compared to the nominal operation without WFFC. Participation in the public showcase study is open for all academic and industrial experts. Every participant will be involved in the final publication which will demonstrate the performance of different WFFC tools in the defined showcases. Instructions on how to participate are provided on How to Participate.

The market showcases provide (future) scenarios in which WFFC should or can contribute to ensure feasible participation of WFs in relevant markets, such as intraday or balancing markets. The developed showcases serve to evaluate the potential benefits of WFFC.