The creators of wind turbines have for many decades now been working to harness one of the most powerful forces in nature. They have moved from onshore to offshore locations and have built ever larger rotors with huge wings, each now longer than a row of 10 London buses. And they have stacked these rotors on top of dizzying towers, and they have constantly reached new, windy heights.
In their endless quest to capture the most reliable energetic winds, engineers are now moving further out to sea, to areas of deeper water where especially strong winds is known for blowing. For offshore wind turbines – whose fixed foundations can only extend 60 meters down – such areas have long been banned. But a new generation of floating machines seems to be changing that.
The potential bounty is huge. According to the industry body Wind Europe, 80 percent of the offshore wind resource in European waters is places too deep to make today’s solid bottom turbines an economically sensible choice. Deep water has also prevented the installation of large offshore wind farms off the west coast of the United States, for example.
Floating turbines can open large parts of the ocean for electricity production. But different designs of liquid turbine compete for cost and efficiency. It’s time to start chasing a winner, given many billion of dollars currently investing in the floating offshore wind industry and the war in Ukraine potentially speed up the move away from fossil fuels.
There is also extra pressure because the industry, despite record high offshore wind installations in 2021, is not living up to what is needed to limit climate change, according to a new report from the Global Wind Energy Council (GWEC).
The council states that floating wind is “one of the most important game-changers” in the industry. But the particular technical challenges of placing wind turbines on floating platforms, where they have to contend with the raw forces of stormy seas and unpredictable weather, have given rise to a surprising number of potential solutions.
Take the Norwegian company Wind Catching Systems (WCS). The staff who have spent five years working on their design for a giant waffle-shaped frame adorned with no less than 126 wind turbines with four rotors – like a giant Connect 4 set studded with rotating blades. The entire structure, which stood as tall as the Eiffel Tower, would sit on top of a floating platform, akin to those used by oil platforms.
Norway intends to install 30 GW offshore wind by 2040. It would take between 1,500 and 2,000 floating platforms if each carried a single traditional turbine. “We could do it with 400,” says Ole Heggheim, CEO of WCS. And although the 126 turbines in WCS ‘design only have a capacity of 1 MW each, they are located so close together that they actually help drive each other.