PO187

Multi-terminal Offshore Grid for the North Sea Region for 2030 and 2050 Scenarios

Matti Koivisto 1, Poul Sørensen1, Petr Maule1, Thure Traber2
1Technical University of Denmark (DTU), Department of Wind Energy, Roskilde, Denmark, 2Technical University of Denmark (DTU), Department of Management Engineering, Kgs. Lyngby, Denmark

Abstract

Offshore interconnectors to neighboring countries are already a crucial element in the Nordic electricity markets. Previous research suggests that offshore grids can significantly reduce the overall socio-economic costs of the transition to a sustainable energy system, especially with offshore wind. This paper considers a multi-terminal offshore grid with wind farms connected to offshore hubs in different wind power scenarios. The newest Wind Europe scenario for offshore wind installations is used as the 2030 scenario, and as the basis for a 2050 scenario.

The multi-terminal grid means that a single offshore hub can, for example, be connected to United Kingdom, Denmark and Norway. Such a hub is a connection point for nearby offshore wind farms. In contrast to connecting each wind farm to onshore (a two-terminal radial connection), such multi-terminal grid allows the generated wind power at a hub to be transformed to different countries based on the spot market without the need to transfer it first to onshore. Also, when wind generation at a hub is low, the multi-terminal grid can be used as an additional interconnection between the different countries.

In addition to proposing an offshore grid and the hub locations, this paper describes the expected variability in offshore wind generation in the different scenarios. The use of these simulations and other presented results in further studies is discussed.

Method

An extensive offshore wind farm database with current and planned farms is used to pin point the most likely locations for wind farms so that the aggregate installed capacities in the different scenarios are reached for each analysed country in the North Sea Region. With the expected spatial wind farm positions in the scenarios, offshore hubs are considered for the major offshore wind farm clusters. A multi-terminal offshore grid is then proposed based on these hubs.

The CorWind software is used to simulate wind generation time series representing the generation at the offshore hubs and at the offshore wind farms connected radially to onshore. CorWind provides representative wind generation times series with detailed modelling of both temporal and spatial dependencies.

Results

The geographical distributions of the offshore wind farms and the offshore hubs are presented for the analysed scenarios. The planned offshore wind farms are connected either to these hubs or to onshore based on the distance to the closest hub and to onshore. A multi-terminal offshore grid is then proposed, and compared to previous studies on the North Sea offshore grid. The multi-terminal grid is compared to the traditional set-up of radial interconnections between countries and only radial connections from offshore wind farms to onshore.

The expected variability in offshore wind generation in the different scenarios is presented, and the use of the CorWind simulations in system operation (including spot market and power system balancing analyses) and power system adequacy and reliability studies is discussed.

Conclusions

This paper considers a multi-terminal offshore grid for 2030 and 2050 scenarios, where the offshore wind farms are allocated to offshore hubs or connected radially to onshore depending on the distance to the closest hub and to onshore. The presented scenarios are based on the newest Wind Europe scenarios. The differences between such multi-terminal grid and a traditional set-up with only radial connections are showcased, and the advantages of the multi-terminal set-up are discussed.

The paper also describes the expected variability in offshore wind generation in the different scenarios, and discusses the use of the presented simulations and other results in system operation and power system adequacy and reliability studies.

Objectives

The delegates will learn about the advantages of a multi-terminal offshore grid with offshore hubs compared to a traditional set-up with only radial connections. A detailed geographical view of the offshore wind farms and the offshore grid is presented based on 2030 and 2050 scenarios.

The delegates will also learn about the expected variability in offshore wind generation in the different scenarios, and about using the presented results in system operation and power system adequacy and reliability studies.