Denmark, the country that built the world’s first offshore wind farm, is set to execute another ambitious plan for its next global first—an artificial island capable of handling 10 GW of offshore wind energy in the North Sea. Currently, around 12 GW of energy is supplied by offshore wind capacity across Europe. Given that the European Union (EU) intends to depend entirely on renewable energy by 2031, this move to launch an artificial offshore wind island will be a critical boost to the world’s offshore wind capacity.

The island is currently in its initial phase of construction, involving the installation of approximately 200 wind turbines with a combined capacity of 3 GW. The island, which is expected to be operational at full capacity by around 2033, will act as a major renewable energy hub and will supply energy to a staggering 10 million homes. In addition, once fully developed, the energy island will provide enough green fuel to supply all ship and aircraft refuelling in Denmark.

The power transmission system from the energy hub to Denmark will be built and owned by the national transmission system operator (TSO) Energinet. The project is being considered as a potential blueprint for other coastal nations to develop their own green energy sources as it can easily be replicated in any other country.

The Nordic country, with its favourable wind speeds, was a pioneer in both onshore and offshore wind, building the world’s first offshore wind farm almost 30 years ago. With another massive project like this, Denmark is making steady headway in utilising the abundant potential of offshore wind energy in the country. It is strengthening its position in the European energy market via power generation from large-scale offshore wind and engaging in power trade with its neighbouring countries.

Denmark plans to add up to 7.2 GW of offshore wind capacity between 2027 and 2030. The plan is part of a COVID-19 recovery stimulus originally outlined in May 2020, but the agreed capacity exceeds the targets laid out. With such ambitious targets to achieve, the Nordic country also decided to halt its search for oil and gas in the North Sea in December 2020. Such efforts are key given new climate-first commitments from countries around the world. 

About the hub

The energy island will be based on a platform and will serve as a hub for electricity generation from surrounding offshore wind farms. The energy hub will serve as an offshore power plant gathering green electricity from hundreds of wind turbines surrounding the island and distributing it directly to consumers in countries surrounding the North Sea. The long-term ambition is to be able to store green electricity on the island, convert it to liquid green fuel and send it via subsea cables to Denmark and neighbouring countries.  The final location of the energy island and the associated areas for offshore wind farms will be decided by spring 2021.

The project will be developed through the public private partnership route between the Danish state and private companies. The State will own the majority of the island, but private companies will be crucial for the project to fulfil the potential with regard to innovation, flexibility, cost-effectiveness and business potentials. Details about the ownership of the island are expected to be specified in order for a tender for private partnerships to be opened.


In 2020, Denmark, the largest oil producer in the EU (Norway and UK are not in the bloc), committed to ceasing all oil and gas extraction activities in the North Sea by 2050, the same year the EU has targeted for bloc-wide climate neutrality (which slates achieving net zero carbon dioxide emissions). According to Denmark’s Ministry of Climate and Energy, offshore wind energy in the North Sea has immense potential, and by 2040, regional nations expect the total capacity of regional windfarms to reach 150 GW, which would be enough meet the electricity demand of 150 million households.

With this background, in February 2021 the Danish government approved the plan to build an artificial island in the North Sea as part of its effort to switch to green energy. The idea is to connect and distribute power between Denmark and neighbouring countries. In February 2021, Belgium’s TSO Elia and Energinet signed an agreement to assess by the end of 2021 whether it would be possible and advantageous to connect Belgium and Denmark with an electricity interconnection via the future energy island in the North Sea. Following the signing of the agreement between Elia and Energinet, the energy island in the North Sea is now central to assessing three possible electricity interconnections to Germany, the Netherlands and Belgium. Energinet is already cooperating with German and Dutch colleagues on looking into similar international connections. If the electricity interconnection between Denmark and Belgium becomes a reality, it will pass through the offshore waters of four different nations, and will probably be the world’s longest high voltage direct current (HVDC) cable.

Figure 1: Connecting link for Denmark and Belgium in North Sea
Source: Energinet

Earlier, in June 2020, the Danish Parliament decided to initiate the construction of two energy islands, which will export power to mainland Denmark and neighbouring countries. One of these islands is the aforementioned project in the North Sea and the second island, called the island of Bornholm, will be located in the Baltic Sea. The move came after the EU announced its plans to transform its electricity system to rely mostly on renewables within a decade. It is also an important part of Denmark’s legally binding target to cut greenhouse gas emissions by 70 per cent by 2030 from 1990 levels, one of the world’s most ambitious of such targets.

In January 2021 Germany’s TSO 50Hertz and Energinet signed a Letter of Intent to collaborate on the Bornholm Energy Island project in the Baltic Sea. The Bornholm Energy Island would connect Germany and Denmark to an offshore hub with around 2,000 MW of wind power capacity that is planned on the island of Bornholm. The German and Danish grids would be connected by means of an interconnector during the first phase of the development. The electricity from the offshore wind farms surrounding Bornholm would be fed into this interconnector on the island. In the following phases, connections to other littoral states and offshore wind farms of the Baltic Sea would be developed gradually.

The two TSOs plan to carry out feasibility studies before the end of 2021. In the future, other partners from the Baltic area are expected to join this initially bilateral cooperation.

An advantage of the Bornholm project, compared to other planned offshore hubs in the North Sea, is that a natural island is already available. This makes it possible to efficiently and flexibly construct the installations. As a result, they will become an example for other hybrid projects and further offshore development.

According to the Danish Energy Agency, as part of the Climate Agreement for Energy and Industry, Denmark wants to become the first country in the world to begin working on such energy islands, which are expected to be completed by 2030.

Scale of the project 

The scale of the project, which will be located in waters almost 80 km off the coast of Jutland, the large peninsula which contains the Danish mainland, is massive. It will act as the transmission centre for hundreds of wind turbines surrounding it.

The initial phase for the artificial island will cover an area around the size of 18 soccer pitches. Initially, approximately 200 offshore wind turbines will send electricity to the hub. It will be capable of producing 3 GW of electricity, but the plan is to scale up to 10 GW, which is nearly one-and-a-half times Denmark’s current needs and would be enough to power 10 million homes in Europe. Depending on its final capacity, the island will cover an area between 120,000 and 460,000 square metres.

The estimated cost of building the artificial island with 10 GW of capacity and the required transmission grid is USD33.97 billion. With this it is being considered as the largest construction project in Danish history. Apart from supplying power to other European countries, the project also aims to  produce green hydrogen from seawater, which can also be exported. Large batteries on the island will store surplus electricity for use when demand is high.

Summing up

Denmark’s landmark agreement on the construction of an energy hub in the North Sea is a significant step in the green transition. This decision marks the start of a new era of sustainable energy production in Denmark and the world and it links very ambitious climate goals with growth and green jobs.