By: Akshat Rathi
Wind farms need a lot of space—not something the world has much to spare. That’s why they’re being pushed out into the sea.
TenneT, the operator of the Netherlands’ electric grid, has come up with an ambitious plan to build an artificial island in the middle of the North Sea that on completion would support the world’s largest wind farm.
The location for the artificial island is a region called the Dogger Bank, about 100 km (60 miles) off the coast of Yorkshire in the UK. During the last Ice Age some 20,000 years ago, when sea levels were 100 meters lower than today, Dogger Bank was actually a landmass called Doggerland, which connected mainland Europe to the British isles. The bank’s shallowness means it won’t require ungodly amounts of sand to build the island, and it will be able to support the thousands of wind turbines that need to be tethered to the sea floor. Its location also puts any electricity generated from the farm within reach of five countries.
Wind power generators are searching for better locations because wind farms are a much less dense form of electricity generation compared to fossil-fuel power or nuclear power. A nuclear power plant can generate 400 times as much energy per unit of area compared to a wind farm.
Sea-based wind farm locations need to be close to land or, as is the case with Dogger Bank, need to use additional equipment to reach the land that wants to use its power. Wind turbines create alternating current, which suffers greater losses when being transported over longer distances than direct current. TenneT plans to build equipment to convert the alternating current to direct current, which can then be transported to the UK, the Netherlands, and later to Belgium, Denmark, and Germany, before being converted back to alternating current for use in homes and industry. Wind power firms like Ørsted and Innogy have shown interest in installing the wind turbines.
The largest offshore wind farm currently is the London Array, which can produce 630 MW of power and covers an area of 122 sq. km (47 sq. miles). TenneT’s proposed plan will create a wind farm capable of producing 30 GW of power over about 6,000 sq. km (2,300 sq. miles). That’s about twice the amount of total offshore wind power installed across Europe today, over an area about eight times the size of New York City. If all goes as planned, the wind farm could be up and running by 2027.
Because it needs additional equipment and more expensive maintenance, offshore wind power is costlier than its onshore cousin. But onshore wind farms aren’t always desirable to locals. Still, the space offered by offshore isn’t limitless—many of the best offshore sites are fast filling up, Rob van der Hage, TenneT’s program manager, told The Guardian. “The big challenge we are facing towards 2030 and 2050 is onshore wind is hampered by local opposition and nearshore is nearly full,” van der Hage says. “It’s logical we are looking at areas further offshore.”