TenneT Netherlands, TenneT Germany, Energinet, Gasunie and Port of Rotterdam joined forces to develop a large scale European electricity system for offshore wind in the North Sea. The North Sea Wind Power consortium partners consider the project to be an important possible alternative path of an internationally coordinated roll-out towards accomplishing the green energy transition and achieving the Paris Agreement. By developing the North Sea Wind Power Hub project, the consortium endevours to make the energy transition both feasible and affordable. Central to the vision is the construction of one or more hubs at a suitable location in the North Sea with interconnectors to bordering North Sea countries. The whole system may function as a hub for transport of wind energy, an interconnection hub to the connected countries, a working hub for offshore wind developers and a location for possible Power to Gas solutions..
Hub and spoke
One or several offshore wind hubs with interconnectors (spokes) linking to energy markets around the North Sea. More wind power and spokes could be added incrementally on a modular basis.
Offshore hubs in the North Sea could each connect up to 30 GW wind power and distribute generated power to European markets through direct current (DC) interconnectors (spokes).
Several wind farms will connect to the hub through alternating current (AC) cables. From the hub, the generated power will be transmitted to markets around the North Sea based on market signals. Thus, the DC cables will be serving two purposes by both distributing the generated wind power as well as bridging power highways for international trade between price zones.
The concept builds on a modular approach where additional wind power and/or spokes could be added step-by-step with limited extra costs.
The modular hub and spoke concept is at the core of the NSWPH project and is an alternative to the current approach of connecting each offshore wind farm directly (radially) to the national grids onshore as well as point-to-point interconnectors.
The project partners are in the process of analysing costs and benefits of the hub and spoke concept and its three main elements (artificial island/hub, wind farms including grid connection and, lastly, interconnectors). First results are positive, yet uncertain in nature due to the assumptions and indicative scope.
2-3,000 wind turbines. A wind power hub of 30 GW equals 2-3,000 future offshore wind turbines. For reference, the total grid connection in one year (2016) of offshore wind in Europe reached 338 wind turbines totalling 1.5 GW.
40 -> 100%. The hybrid nature of the hub will increase the efficient utilisation of a connection to the mainland from roughly 40% (radial) towards 100% (hybrid).
30 GW. One hub could connect up to 30 GW wind power. Several interconnected hubs could potentially connect even larger amounts.
First results from the preliminary studies carried out by project partners are positive and indicate net socio-economic benefits of interconnectors to a North Sea Wind Power Hub with associated uncertainties.
Exploring design, functional and location options of an artificial island hosting a Wind Power Hub.
The vision is to build an artificial island in the North Sea at a central location and in shallow waters, with optimal wind conditions. The island would be a large connection point for thousands of future offshore wind turbines and create a near-shore environment far out at sea.
An island would constitute a permanent base for personnel to undertake construction and maintenance activities at surrounding wind farms as well as host synergy technologies such as Power2Gas. This together may enhance the attractiveness of building far out at sea.
In developing possible locations for large-scale offshore wind and a North Sea Wind Power Hub, the project partners will take due account of expected short-term and long-term ecological impacts.
Power to gas
Power2Gas (P2G) and potentially other technologies look promising in bringing synergies to the project and in strengthening the business case.
With mass scale wind power roll-out and one or several hubs in the North Sea, conversion and storage solutions such at P2G could help balance and stabilise power transmission to onshore markets, limiting investments in interconnectors.
P2G is also likely to lead to an improved business case for offshore wind farms connected to a hub as peak power production could be used for conversion instead of being sold at a low market price or even curtailed due to possible interconnector constraints.
The costs of energy transmission and long-term storage in the form of gas are currently considerably lower per unit of energy than if the energy is transmitted and stored in the form of electricity. Combining the strengths of the power and gas supply systems could provide a boost to the use of hydrogen and could potentially be brought ashore via the existing offshore gas infrastructure.