Together, the four transmission system operators form a partnership that studies and investigates the possible development of a large-scale, sustainable European energy supply system in the North Sea. The collaboration is a key step towards the realization from 2030-2050 of a North Sea Wind Power Hub which will make a major contribution towards achieving the objectives of the Paris climate agreement (COP21). In order to achieve the climate targets for Europe alone, approx. 230 gigawatts (GW) of offshore wind energy capacity needs to be developed, of which 180 GW in the North Sea.
The volumes of offshore wind energy required for the energy transition are so large that gas-based transmission and storage solutions shall be deployed in addition to electricity connections. The costs of energy transmission and long-term storage in gas form are considerably lower per unit of energy than if the energy is transmitted and stored in the form of electricity. In addition, combining the strengths of the electricity and gas supply system can provide a key boost to the use of hydrogen as a sustainable solution in numerous applications in industry, transportation, and the built environment.
Power Link Islands in the central North Sea
By developing the North Sea Wind Power Hub – which will be able to support offshore wind farms with a total capacity of 100 GW – the consortium wants to make the European objectives feasible as well as affordable. It will supply a substantial part of Europe’s future sustainable power. The basic idea of the plan calls for the construction of one or more so-called ‘Power Link Islands’ in the central North Sea (possibly the Dogger Bank), with interconnections to the countries bordering the North Sea. Such artificial islands will be situated at a location that offers ideal wind conditions, i.e. frequent high wind speeds. It will be possible to connect a large number of offshore wind farms to a Power Link Island. The location facilitates the distribution and transmission of wind generated electricity via direct-current connections to the North Sea countries (the Netherlands, Belgium, the United Kingdom, Norway, Germany, and Denmark). The electricity transmission cables (‘Wind Connectors’) will not only transmit wind energy to the connected countries, but will simultaneously serve as interconnectors between the energy markets of the aforementioned countries, enabling them to trade electricity across their borders. In addition, the expected power surpluses can be converted to hydrogen for large scale transport to shore, storage or buffering purposes.
Transmitting and storing renewable electricity in the form of hydrogen
Gasunie will contribute expertise in the transport and storage of gas via interconnected international grids, and managing the balance between the supply of and demand for energy. The company is also developing knowledge about the use of renewable gases such as hydrogen, and is looking into various conversion processes, including power-to-gas (hydrogen) conversion. This process uses electrolysis to store and transport (internationally) large quantities of renewable energy in the form of gas. Conversion into hydrogen is expected to play an important role in the North Sea Wind Power Hub system. It will enable wind-generated energy to be stored in the form of gas close to remote off-shore sources, and then brought ashore via the existing offshore gas infrastructure, for instance.
North Sea Wind Power Hub vision: member states can only realize energy transition by joining forces
Large-scale solar and wind energy generation is necessary because achievement of the European CO2 emissions reduction targets is mainly dependent on sustainable electricity production. Wind and solar energy complement each other: there is more sun from spring to autumn, and more wind in the colder and darker months of the year. So a future-proof sustainable and stable energy system will need solar as well as wind energy, both on a large scale. This requires close collaboration and synergy because such a system cannot be realized by individual EU member states on their own.
In short, one or more Power Link Islands in a central location in the North Sea will fulfil all the criteria to ensure the success of wind energy generated far out at sea:
- Large wind farms far out at sea will be connected to a Power Link Island, effectively turning ‘far shore’ into ‘near-shore’; economies of scale will also reduce costs.
- Direct-current connections will double as cross-border electricity connections (interconnectors), significantly increasing the efficiency of these connections, which generally amounts to approx. 40 percent.
- Personnel, components, assembly workshops and installations for power-to-gas conversion can be stationed on the islands, thus optimizing and simplifying complex offshore logistics as well as the conversion of electricity.
- An area which has frequent strong winds will optimize the yield.
- The water in this area is relatively shallow. The shallower the water, the lower the construction costs of the offshore wind farms and artificial islands.
- An island in an area with a lot of space will provide the scale necessary to reduce costs (through economies of scale).