Bornholm Energy Island is blazing the trail for offshore expansion in the Baltic Sea

Energinet and 50Hertz (Germany’s TSO) have now reached an important next step in their cooperation on Energy Island Bornholm. In November, they expanded their existing cooperation with new agreements on, amongst other things, ownership and costs of the power cables and power installations that is going to breathe life into the very heart of Bornholm Energy Island. At the same time, Energinet’s business case for Bornholm Energy Island’s electricity infrastructure demonstrates that connecting to both Germany and Denmark is a much better idea – to the tune of billions of Danish kroner – than connecting to Denmark alone.

Read Energinet’s business case for Bornholm Energy Island’s electricity infrastructure here

Over the summer, the political parties behind the agreement on the two energy islands in Denmark entered into an agreement to increase the power generation capacity of the offshore wind farms off Bornholm from the originally agreed 2 GW to 3 GW. Similarly, a political agreement (a Memorandum of Understanding) has been entered into between the governments of Denmark and Germany for the interconnection of Bornholm Energy Island with Germany. 

Since then, the two countries’ TSOs – 50Hertz and Energinet – have joined forces to implement the principles of the political agreement concerning the distribution of ownership, costs and earnings in a TSO agreement on the construction and operation of the cables and facilities needed to transmit power from the wind farms to Germany and Denmark. 

Hanne Storm Edlefsen, who is heading up Energinet’s energy islands efforts, says: “Together with our German partner, 50Hertz, we have taken a significant step towards establishing Bornholm Energy Island. The power installations and cables are the heart of Bornholm Energy Island, and these must ensure that Bornholm becomes a hot spot for the development of green energy from offshore wind power throughout the Baltic Sea Region.”

Sound economics in Bornholm Energy Island’s electricity infrastructure 
In cooperation with local authorities, residents, and landowners, Energinet is already in the process of determining exactly where to position the large onshore converter stations and power cables.

The agreements are based on the political terms of reference and ensure that the project moves ahead and comes closer to being realised. In addition, Energinet’s business case for Bornholm Energy Island’s electricity infrastructure makes it possible to get a more accurate idea of the economic implications of the high-voltage substations and power cables to be used to integrate offshore wind into the power grids of multiple countries.   

Energinet has a mandate to invest in facilities and cables for large-scale projects, as the Danish Minister for Climate, Energy and Utilities has issued a so-called Section 4 approval of the project, in this case Bornholm Energy Island’s electricity infrastructure. This approval was issued by the Minister on 4 October 2022, on the basis of the business case.

In accordance with standard practice, Energinet has been working on the business case for quite some time, as it has to some extent informed the decisions by the Minister and the political parties behind the energy islands agreement.

Energinet’s task has been to illuminate the economic value to society of the electricity infrastructure itself for Bornholm Energy Island by comparing two alternatives: an electricity interconnection with both Germany and Denmark compared to an electricity interconnection with Denmark alone.

Energinet’s business case shows that there are economic gains from both solutions, but that the gain is roughly DKK 20 billion greater for a hybrid energy-island interconnection between Denmark and Germany based on the establishment of 3 GW of offshore wind power. A hybrid interconnection is an electricity connection that both brings offshore wind power ashore in the two countries and interconnects their electricity markets. 

At the same time, the business case shows that, by itself, the climate impact of the electricity infrastructure for Bornholm Energy Island is clearly greatest at European level with an estimated carbon emission reduction of just over 3 million tonnes in Europe by 2040. Thus, Bornholm Energy Island assists in making Europe greener.

“I’m pleased that we have now reached a good agreement with our German


Receive notifications directly by e-mail