Above: Schematic view of the energy island.
Below: Facility with Power-to-X technology.

Denmark aims to build world’s first energy island

An artificial island, with wind power and installations to convert excess energy into fuel, is planned in the North Sea. When completed it may provide electricity for 10 million households.

Energy islands like this will allow wind turbines to be placed significantly further from land and be more efficient at distributing the generated electricity to multiple countries. The island will be situated 80 km off the west coast of Jutland. The energy hub will serve as an offshore power plant, gathering and distributing green electricity from thousands of wind turbines surrounding the island directly to consumers in countries around the North Sea.

The island is expected to have a total area of 150,000 square metres and a depth of 20–30 metres. Political agreement on the construction of an energy hub in the Danish North Sea was reached in February 2021, with the aim of installing 200 wind turbines with a combined capacity of 3 GW in the first phase of the project (by 2033), and expanding this to 10 GW in the second phase (by 2040). The electricity will be distributed between Denmark, Germany and the Netherlands.

The project is only the latest step in Denmark’s push for sustainability. Last year the nation pledged to reduce greenhouse gas emissions by 70 per cent from 1990 levels and to achieve carbon neutrality by 2050. In late 2020 it also ended oil and gas exploration in its North Sea territory. Denmark has the highest proportion of wind power in Europe and globally. It was the first country in the world to construct an offshore wind farm, in 1991. And in 2019, Denmark generated 47 per cent of its total electricity needs from wind power. In the same year the Danish wind power industry employed roughly 32,000 people full-time. Danish Vesta, one of the world’s largest wind power companies, had a turnover of just over €15 billion in 2021.

The Danish Energy Agency has selected the Swedish engineering consultancy Sweco as the adviser on the North Sea Energy Island for the next nine years. Under the €54 million contract, which is capped at around €81 million, Sweco will provide the Danish Energy Agency with technical advice throughout the remaining phases of the North Sea Energy Island project, including tendering, design, construction and the final handover. “The energy island is at the forefront of technology development and it will be interesting to follow the development of energy transmission and storage in the future,” says Tore Lucht, head of the ocean and geological department at Sweco in Copenhagen.

The energy island will be built using Power-to-X technology, which is considered a key factor in reliable wind power supply. This means that when there is a lot of wind, but low demand for electricity, the surplus can be converted into hydrogen and climate-neutral fuels, which can be used by aircraft, ships and heavy industry.

The artificial island is one of two energy islands that Denmark will establish as part of the green transformation of the energy sector. The Danish parliament has also decided to build a smaller energy island for wind power on Bornholm in the Baltic Sea, but the energy island west of Jutland is significantly larger. When fully developed, this energy island will produce 45 TWh (terawatt hours) per year. Other countries are also looking to build similar energy islands.

The innovators behind the energy islands hope their project is only the beginning. As offshore wind technology matures, it could tap into tremendous unrealised potential. And if this experiment succeeds, the model it tests in the North and Baltic seas could soon be imitated by coastal nations around the world.

Emilia Samuelsson


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