Norwegian “Windcatchers” could revolutionize offshore wind energy
Rather than one tall turbine, Windcatchers are comprised of a grid of 120 mini turbines.
What looks like little box fans are stacked on top of each other, and side-by-side, to form a giant floating “sail” as tall as the Eiffel Tower.
Their tiny blades produce 2.5 times more electricity per square foot than conventional wind turbine blades because they spin faster and turn more rotors.
Just five Windcatchers produce the same amount of electricity as 25 wind turbines, while taking up less of the ocean’s surface area.
“Tests have shown several small rotors close to each other, in sum, produces more power than if you have each one standing individually,” Ronny Karlsen, CFO of Wind Catching Systems, told IFLScience.com.
Because they have less distance to travel, the small blades spin faster than large blades, generating more energy.
Windcatchers can also handle higher wind-speeds than turbines without getting damaged, and can therefore be tethered farther offshore.
“Utilizing the full energy in higher wind speeds and the multi-rotor effect, the Windcatcher generates 2.5x more annual energy per swept area than a conventional turbine,” says WindCatching.com.
“Our goal is for customers to be able to produce electricity that competes without subsidies with other energy sources. Simply put, we will deliver floating offshore wind with the costs of bottom-fixed solutions,” said Ole Heggheim, CEO of Wind Catching Systems.
One windcatcher is expected to power 80,000 European homes and last for 50 years, compared to 30 years for traditional turbines.
The Norwegian start-up company also believes its invention will kill fewer birds than conventional turbines.
“What we’ve been told – and it needs to be verified – is that since this is almost like a wall of turbines, a bird wouldn’t … fly straight through it. It would be very visible,” Karlsen said.
“One of the problems you have with … conventional rotors is that it seems like they’re spinning around slowly, but they’re not. They’re spinning around really fast, so the bird thinks, “oh I can fly through here, I see nothing” – and then suddenly a blade comes around.”
The company hopes to have Windcatchers on the ocean by 2023.