Denmark has approved a plan to build an artificial island in the North Sea that will be a hub to hundreds of offshore wind turbines, 260m tall, that will generate 10GW, enough energy for 10 million households. The first stage will be the size of 18 soccer pitches, for 3GW, costing €29bn ($34bn), and should be operational by around 2033. Writing for the World Economic Forum, Douglas Broom says that the ultimate goal of 10GW should be more than enough for the whole of Denmark. The spare capacity will be used both to sell on to other nations and to create green hydrogen from sea water. Large batteries on the island will also be used to store surplus electricity. The sheer scale of the project can be a driver for multiple technologies and a model for other coastal nations as global offshore wind installations continue to rise. Ambitious projects like this are needed if the EU wants to hit its renewable electricity targets and increase offshore wind energy capacity 25-fold by 2050. Broom ends by quoting the Chairman of Ørsted, the wind farm major, as saying that offshore wind should also be seen as an opportunity to work with other ocean-based sectors like mariculture and fisheries.
Denmark, the nation that built the world’s first offshore wind farm, has agreed to an ambitious plan for another global first – an energy island in the North Sea which could eventually be capable of supplying energy to a history-making 10 million homes. The move will create a critical boost to the world’s offshore wind capacity.
The first “hub and spoke” energy scheme will involve building an island 80 kilometres off the Danish coastline to act as the transmission centre for hundreds of wind turbines surrounding it. At $34 billion, it’s the largest construction project in Danish history.
The project is also a potential blueprint for other coastal nations to develop their own green energy sources. “It’s in Danish waters, yes, but it could conceptually be in any other country,” said Peter Larsen of the North Sea Wind Power Hub Programme.

The first “hub and spoke” energy scheme will involve building an artificial island 80 kilometres out to sea. / Image: Danish Energy Agency
Energy hub for Europe, model for the world
The initial phase for the artificial island is around the size of 18 soccer pitches. Initially, the North Sea hub will be capable of producing 3 gigawatts of electricity, but the plan is to scale up to 10 gigawatts, which is nearly one-and-a-half times Denmark’s current needs.
As well as supplying other European countries with electricity, the goal is to use the new offshore island 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.
Although the Danish government will own a majority stake, private companies will be invited to join a public/private partnership to build the project. Power will be supplied by as many as 600 giant wind turbines, each standing up to 260 metres tall.
Offshore Wind installations rising globally
Such efforts are key given new climate-first commitments from countries around the world. As Reuters has reported, the European Union intends to depend mostly on renewable electricity by 2031, increasing its offshore wind energy capacity 25-fold by 2050.
Offshore wind installations saw a slight dip in the mid-2000s, but have been growing ever since. In fact, 2020 saw record-breaking financial investments into offshore wind, according to new data from The Renewables Consulting Group.

Image: Global Wind Energy Council

Offshore wind capacity additions by country or region, 2016-22 / Image: IEA
A boost to mariculture, fisheries
The scaling up of offshore wind should be the catalyst for other ocean-based economic activities worldwide, according to Thomas Thune Andersen, Chairman of Danish green energy company Ørsted, which built the Vindeby wind farm.
“Setting up wind farms does have an impact on the local environment,” he told the World Economic Forum’s 2021 Davos Agenda virtual event. “But it’s also an opportunity to do other things,” he said.
There is a need “to set ambitions high” when it comes to offshore renewable energy, Andersen said, and to enable other activities in the same area, such as mariculture.
Governments, NGOs and businesses “all need to hold hands in order to do this,” he said. “We have seen very good examples already of seaweed farming, talking to fishermen about how we optimise that, how we build reefs and how we create other kinds of nurseries for fish.”
Andersen is one of more than 65 global leaders from business, civil society, international organisations, science and technology who comprise the Friends of Ocean Action, an initiative convened by the Forum to fast-track solutions to the most pressing challenges facing our oceans.
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Douglas Broom is a Senior Writer at Formative Content, writing for the World Economic Forum
This article is republished in accordance with the Creative Commons Attribution-Non Commercial-No Derivatives 4.0 International Public License
I could understand energy islands if they simultaneously became a hub for the exchange of electricity between the surrounding countries, but that would require the cables to be laid in a different way than directly between a country or region in one country and to another country. Eg. Vikinglink could with advantage be layers via an energy island instead of directly from Denmark to the area around London in the UK at the same time as the cable to the Netherlands was rerouted so that in future it will go via the energy island.
Let’s see, 10 GW nameplate capacity for supplying 10 million homes. That works out to 1 kW per home. Multiply that by a duty factor of 25%, and one gets a whopping 250 W average power. One will be hard pressed to charge an EV battery with that amount of power. A refrigerator requires more power than 250 W. One will be able to keep a few lights on and maybe watch a little TV. The phrase dumber than dirt is applicable.
Resilient? No. Easily overwhelmed in extreme weather, as comes with climate change
Secure? No. Easily captured by terrorists/enemies
Reliable? No. Renewables are intermittent, as Germany begins to understand at last
Long term investment? No. Wind turbines only last 20-25 years.
Could produce hydrogen? Expensively by intermittent low temp electrolysis
Could do worse? Doubtful.
The only way to meet that need is nuclear to provide electricity and the steam generated used to crack water into hydrogen. They’ve been doing it since 2004. The three significant nuclear incidents Chernobyl- Fukashima and Three Mile island have caused less than 200 deaths. They say about 6000 developed thyroid cancer. It is reported that 8 million people die each year from pollution associated with fossil fuels. I don’t know that I agree with that but it’s out there. So we look at the short service life of wind turbines and solar panels and look at the fact that Germany the world leader in solar and wind pay 40% more for their electricity than France who is 75% nuclear power. The fact that rare earth metals mining is extremely polluting and the cast of batteries in electric cars will be a toxic waste nightmare.
Uranium mining is even worse as it pollutes huge amounts of water and soil for just a small amount of usable Uranium. There are different ways of counting deaths from nuclear waste and accidents as radiation has long term effects on mortality and genetics.