THISTED, Denmark — Standing beneath Europe’s tallest and most powerful wind turbine feels hypnotizing: the three giant blades turn rhythmically with a soft repetitive woosh, sweeping across an area equal to six soccer fields. One turbine alone could power 20,000 European households.

At 918 feet (280 meters) tall, this giant is the biggest of nine turbine prototypes at the Østerild National Test Center in rural northern Denmark, which has some of the best wind conditions in the world. If all goes to plan, hundreds if not thousands of similarly massive turbines could extend beyond the shore and across the North Sea in coming decades.

Right now, Danish turbine manufacturer Vestas is performing hundreds of tests on this 15-megawatt offshore prototype to determine the efficacy and durability of these next-generation turbines. Winds are stronger higher in the atmosphere, so the taller the turbine, the more efficiently it can harness power.

Spanish-German manufacturer Siemens Gamesa and GE Renewable Energy (a division of American company General Electric) are also testing similar prototypes at the center. Despite its technical work, the Østerild center is marked as a tourist attraction on Google Maps, drawing over 30,000 visitors annually.

“The offshore wind turbine is a machine that creates independence, and we need offshore wind if we want to be energy independent from countries such as Russia,” Denmark’s Energy Minister Lars Aagaard, said in Copenhagen in late April during an annual event organized by Europe’s wind industry group, WindEurope.

Europe is betting heavily on offshore wind to decarbonize its energy system and boost its energy security, looking at the North Sea—nestled between seven countries and connected to the Atlantic Ocean—as its next giant green power plant.

Winning that bet will not be easy.

Global supply chain disruptions, higher manufacturing costs and lengthy permitting delays are challenging developers and slowing installation rates. At the same time, plans for novel and sophisticated offshore wind projects spanning borders will require unprecedented cooperation, testing Europe’s ambition and teamwork.

Getting Europe’s North Sea offshore vision right could inspire a model followed by others across the globe, including the United States, which just last week received turbine components for its first large-scale offshore wind farm.

Leaders from nine European countries, including Denmark, Norway and the United Kingdom, pledged in late April to quadruple wind power generated in the North Sea from about 30 gigawatts today to at least 120 GW by 2030, and increase it ten-fold to 300 GW by mid-century.

That’s equivalent to “eight thousand of the largest existing wind turbines in only seven years,” Aagaard told thousands of delegates, a day after the political declaration.

Those targets are “astonishing” with a lot of “complicated work” ahead, said Thomas Egebo, CEO of Energinet, the Danish company in charge of sending energy across the country.

“The wind is blowing nicely in the North Sea, so with 300 GW of capacity you can produce more or less the equivalent of some 50% of European electricity consumption today,” he said.

Getting there will mean charting new waters.

Today, offshore wind farms have point-to-point connections to the shore, delivering renewable electricity generated by the turbines to one landing point. This means only one country taps directly into the green power production from that particular farm.

In the future, the plan is to set up hybrid offshore wind farms. These will connect two or more countries through modern power cables capable of delivering electricity to multiple points. Right now, Europe has one hybrid offshore wind farm, connecting Denmark and Germany through the Baltic Sea.

The ultimate goal—and the most difficult to achieve—is to have so-called energy islands offshore, which would act like power hubs, gathering electricity generated by surrounding turbines and distributing the power to neighboring countries. The islands could also act as sites for electricity storage or for producing renewable hydrogen.

Belgium is planning to build an artificial island 28 miles (45 kilometers) off the Belgian coast in the next couple of years, describing it as “the world’s first international energy hub.”

Denmark has plans for two energy islands: a $34 billion artificial island 62 miles (100 km) off the Danish coast, described as the country’s biggest construction project ever, and another on the Baltic Sea island of Bornholm, which Germany is also eyeing.

Some countries will be net exporters of green energy, others net importers, so agreeing on how to deal with costs, risks and benefits will be key, Egebo said.

Finding win-win solutions will require “good and solid political handcraft” and “unprecedented cross-country cooperation,” he added.

Beyond politics, deploying offshore wind on a large scale also comes with technical challenges.

A big advantage of offshore wind is that one successful project can be technically replicated and scaled up, Pål Coldevin, a high-level executive at the Germany-based energy company RWE, said during a visit to the test site in northern Denmark.

The company operates 19 offshore wind farms worldwide and is currently building Denmark’s largest to date with more than 1 GW of capacity, meant to power over one million Danish households.

Scale is a “big, big plus for offshore,” and is much harder to achieve with onshore wind, said Christian Gjerløv, who leads the offshore products team at Vestas.

That said, challenging weather out at sea makes the installation of offshore turbines more complex, Gjerløv added.

This complexity reverberates across the supply chain as turbines get bigger. Suppliers need to invest in new facilities to accommodate the bigger parts. Only a small number of offshore vessels are currently capable of transporting the bigger turbines, like the ones Vestas is building. Making such big infrastructure adjustments also takes time.

China is developing a giant 18 MW wind turbine prototype (3 MW more powerful than Vestas’), which would be the world’s most powerful turbine.

Europe’s offshore renewable energy industry warned it’s not big enough to deliver governments’ North Sea green power ambition, calling for policy support and funding to get on track.

The average per-megawatt cost of a wind turbine has increased by almost 40 percent over the last two years. Europe invested just €17 billion in new wind farms in 2022, down from €41 billion in 2021 and the lowest investment figure since 2009, according to WindEurope.

“The overall supply chain is now under pressure,” RWE’s Coldevin said. “For us as a developer, it will always be a concern that we get the right product at the right time.”

Source: Wood Mackenzie • The majority of new orders (75-85%) were for onshore wind turbines. Unknown refers to turbine orders in countries or regions not disclosed by the manufacturer.

These challenges did not escape the head of International Energy Agency Fatih Birol, who sent a strong warning to Europe at the wind industry event in Copenhagen.

Developing clean energy technology is like running a marathon, he said. While Europe is currently leading the race in wind energy, the continent was in a similar position with solar power decades ago, before China won out.

“Nobody gives you a gold medal because you were the number one in the first 10 kilometers,” he said. “I really hope that in terms of wind we do not see the same movie [as with solar].”