The makers of wind turbines have, for many decades now, labored to harness one of the mightiest forces in nature. They’ve moved from onshore to offshore sites, building ever larger rotors with huge blades, each one now longer than a row of 10 London buses. And they’ve stacked those rotors atop dizzying towers, constantly reaching for new, blustery heights.
In their endless quest to capture the most reliably energetic winds, engineers are now moving further out into the ocean, to areas of deeper water where especially strong winds are known to blow. For offshore wind turbines—whose fixed-bottom foundations can only extend down 60 meters—such areas have long been off-limits. But a new generation of floating machines looks set to change that.
The potential bounty is huge. According to industry body Wind Europe, 80 percent of the offshore wind resource in European waters is in places too deep to make today’s fixed-bottom turbines an economically sensible choice. Deep water has also prevented the installation of large offshore wind farms off the western coast of the US, for example.
Floating turbines could open up vast swathes of ocean to generate electricity. But various floating turbine designs are competing over cost and efficiency. It’s time to start hunting for a winner, given the many billions of dollars currently being invested in the floating offshore wind industry and the war in Ukraine potentially hastening the move away from fossil fuels.
There’s also added pressure because, despite record offshore wind installations in 2021, the industry is falling short of what’s needed in order 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 key game-changers” in the industry. However, the special engineering challenges of placing wind turbines on floating platforms, where they must contend with the raw forces of stormy seas and unpredictable weather, have prompted a surprising variety of potential solutions.
Take Norwegian firm Wind Catching Systems (WCS). The staff there have spent five years working on it their design for a giant waffle-shaped frame adorned with no fewer than 126 four-rotor wind turbines—like a giant Connect 4 set studded with spinning blades. The entire structure, standing as tall as the Eiffel Tower, would perch atop a floating platform, similar to the ones used by oil rigs.
Norway intends to install 30 GW of offshore wind by 2040. That would take between 1,500 and 2,000 floating platforms if each one carried a single traditional-style turbine. “We could do it with 400,” says Ole Heggheim, the CEO of WCS. And although the 126 turbines in WCS’s design only have a capacity of 1 MW each, they are placed so closely together that they actually help power one another.