Manufacturers wind turbines have been working for many decades to harness one of the most powerful forces in nature. They moved from onshore to offshore locations, building ever larger rotors with huge blades, each now longer than a row of 10 London buses. And they placed those rotors atop dizzying towers, constantly reaching for new, tumultuous heights.
In their never-ending quest to capture the most reliable energy winds, engineers are now moving further 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 up to 60 meters – such areas have long been off-limits. But a new generation of floating machines looks set to change that.
The potential reward is huge. According to industry body Wind Europe, 80 percent of offshore wind sources in European waters are in places too deep for today’s fixed-bottom turbines to be an economically sensible choice. Deep water has also prevented the deployment of large offshore wind farms off the US West Coast, for example.
Floating turbines could open up vast swathes of the ocean to generate electricity. But different floating turbine designs compete on cost and efficiency. It’s time to start looking for a winner, given the many billions of dollars currently being invested in the floating offshore wind industry and the war in Ukraine potentially accelerating the shift away from fossil fuels.
There is also added pressure as, despite record offshore wind installations in 2021, the industry is falling short of what is needed to limit climate change, according to a new report from the Global Wind Energy Council (GWEC).
The council says floating wind is “one of the key game changers” in the industry. However, the particular 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 array of potential solutions.
Take Norwegian firm Wind Catching Systems (WCS). Staff there spent five years working on their design for a giant waffle-shaped frame adorned with at least 126 four-rotor wind turbines – like a giant Connect 4 set studded with spinning blades. The entire structure, as tall as the Eiffel Tower, would be placed on a floating platform, similar to those used by oil rigs.
Norway aims to install 30 GW of offshore wind by 2040. This would require between 1,500 and 2,000 floating platforms, each carrying one traditional-style turbine. “We could do it with 400,” says Ole Heggheim, CEO of WCS. And although the 126 turbines in the WCS design only have a capacity of 1 MW each, they are placed so close together that they actually help each other with power.