Radical plans for artificial islands connecting a series of mega windfarms in the North Sea have inched closer to reality after an initial assessment concluded the idea is technically feasible. The scheme鈥檚 backers say the bold project is needed because the rate offshore windfarms are being built in Europe is not enough to deliver the goals of the Paris climate agreement, and space is running short near coastlines to cheaply connect turbines.
The North Sea Wind Power Hub, backed by a consortium including Dutch energy network firm TenneT, previously envisaged the scheme as . But Michiel Muller of TenneT says the consortium鈥檚 research, , suggests a series of smaller islands would be better than the 鈥済rand vision鈥� of a single big one mooted two years ago.
鈥淭he main message is that we have looked in detail on how we could facilitate a very large scale roll-out of offshore wind as required to combat climate change. And we believe that the concept we present is both technically feasible and economically feasible,鈥� says Muller.
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鈥淚t would be very transformative,鈥� says Kees van der Leun of Dutch consultancy Navigant, which contributed to the research. The proposed scale of the windfarms are 鈥渃ompletely beyond鈥� what is happening off the waters of the UK and Germany today, he says.
The first island hub, one of as many as eight, could built by the early 2030s. Each hub is seen as ideally having a series of windfarms with up to 15 gigawatts of capacity, enough to power more than 12 million UK homes. By comparison, the biggest single windfarms being built in the region today are just over 1GW. The project would not get the benefits of economies of scale if the hubs were less than 10-15GW, while bigger would see long construction times and more financial risk, says Muller.
The windfarms could utilise turbines much bigger than the largest around UK waters today. Today the largest being installed are around 8 megawatts and taller than London鈥檚 鈥楪herkin鈥� skyscraper, but 12MW ones have already been unveiled by turbine makers and 15MW ones are expected by 2030.
Dogger Bank
The proposed island hubs could be connected to Germany, the Netherlands, and the UK, as well as Norway and Denmark (see graphic). However, as the first three countries have the furthest to go in terms of decarbonising their energy supplies, they would probably be focussed on initially, the consortium says.
A future configuration could also use the electricity to produce hydrogen 鈥� seen as crucial for sectors such as industry to decarbonise 鈥� onshore, and later offshore too using desalinisation. The islands would host equipment to convert power supplies in alternating current to direct current for transmitting back to shore with little losses.
The island could be a steel structure, a gravity-based platform or made from sand. Sand is the cheapest in most scenarios, says Muller, but would take up to eight years to construct. Moreover, the consortium says: 鈥渓arge volumes of deposited sand will put strain on the existing seabed and may have reduced stability.鈥�
Four illustrative locations were examined in the region of Dogger Bank, the patch of shallow sand that is a relic of Doggerland, thought to have once connected the UK to continental Europe.
Van der Leun says the scheme鈥檚 success will hinge on whether it gets enough support from governments. 鈥淲hether the project will happen depends largely on policy makers. If they set the right targets, appoint sufficient clustered offshore wind areas, set the right boundary conditions from a market and regulatory perspective the project is likely to go through,鈥� he says.
While the hub might seem a long way off, there is an urgency to get started, he says. 鈥淔or this kind of major infrastructure, lead times are long, and 2030 is around the corner.鈥�
