North Sea Energy Hub (Photo by EUDP)

Energy hubs in the North Sea require new digital solutions

Energy technology
Energy hubs in the North Sea, that can collect and distribute energy from offshore wind farms to the European countries, are challenging the usual way of designing electricity grids. A project led by Technical University of Denmark is now developing new solutions.

An international consortium, called the North Sea Wind Power Hub, is currently investigating how to optimize and utilize wind energy from the North Sea. The potential for wind energy in the North Sea is up to 180 GW.

"This is equivalent to replacing all coal-fired power plants in Europe with wind energy from the North Sea," says Jacob Østergaard, Professor and Head of Center for Electric Power and Energy at DTU Elektro.

In order to be able to harvest the many sustainable gigawatts from the stormy sea between the Netherlands, Germany, the UK, Denmark and Norway, the vision is to increase the number of offshore wind turbines connecting to so-called energy hubs, for example in the form of an artificial island. This allows the wind energy to be collected from the surrounding offshore wind farms and transmitted across Europe - primarily in the form of electricity.

At the Techinical University of Denmark the multiDC project develops intelligent, digital solutions for controlling long distance power flows in order to avoid blackouts and severe failure. The project also looks into how to design the power flows in the Nordic grid with connections to Europe.

"When we get the energy hubs in the North Sea, we will have even more HVDC lines and connection points in the Nordic grid, which must be controlled and coordinated," says Asso. Prof.Spyros Chatzivasileiadis, Techinical University of Denmark and Project Manager for multiDC.

Gigantic offshore power plants

In addition to a greater number of HVDC lines and connection points, the energy islands have to be in balance so that blackouts will not occur on the islands themselves. This is important as they - in conjunction with the connected offshore wind farms - will function as gigantic power plants in the future.

Between 17.00 and 20.00 on weekdays when pots and pans are at use in the kitchen, the washing machine spins and the television entertains the children inside the living room, the Danish consumption reaches 5-6 GW, explains Chatzivasileiadis.

“Each of the planned energy hubs will be able to integrate 10-15 GW of wind energy into the electricity grid. Imagine we lost one of these hubs due to power failure. Denmark could suffer a complete blackout. We are working to prevent this at any time,” he says.

At the same time, the project is working to achieve even better control of the power flows in the high-voltage lines connecting to our neighboring countries. In this way, the countries can to a greater extent exchange the reserves that are available in each country to help the grid prevent imbalances and power failure, for example in the form of power plants ready to increase their production.

“It can be a measure to safeguard against blackouts. The neighboring countries can immediately help each other to balance consumption and production,“ says the project manager.

This will significantly reduce the cost of operating the power system, as you can share the reserves and have a common emergency response.

With intelligent, digital control and coordination methods, Denmark can also save many millions of Euros a year in the Danish electricity system by taking into account the energy losses that arise when dealing with energy across national borders via foreign connections. This requires advanced market algorithms, which the researchers at DTU have developed in the multiDC project.

"In this way, those responsible for the losses will pay, instead of the bill ending up with the Danish system operator and thus the Danish electricity consumers," says Chatzivasileiadis.