This new wind turbine concept isn’t like any we’ve seen before!
A Norwegian startup claims that its strange wind turbine design will be able to produce more than double the electricity of the largest unit on the planet. But first they have to test it.
The type of wind turbine you’re used to seeing in stock photos of wind farms is called a horizontal axis wind turbine (or, HAWT). But there is another form of wind power, called a vertical axis wind turbine (VAWT), in which the blades rotate on an axis perpendicular to Earth’s surface. This type of turbine can work better in unstable wind conditions because they don’t need to be pointed into the wind, but still produce much less electricity and durability problems because of the force the wind exerts on them. That’s why you would only see VAWTs in small applications, like homes, and HAWTs in wind power farms.
But a new company claims to have improved on the VAWT design. The invention could create a turbine with a maximum output of 40 megawatts, far surpassing the 15 megawatts of the world’s current largest turbine. That company is called World Wide Wind, a Norwegian startup. The Norwegians—rich, thanks to their oil and gas reserves—want to dramatically increase their wind energy production to 30.000 megawatts by 2040. Their industry’s interest in offshore wind energy is so big that there is a waiting list to test new technologies off its coast, which is on the incredibly windy shores of the North Sea.
In June 2021, company founder Stian Valentin Knutsen wondered if it would be possible to have two sets of rotor blades on a single turbine mast, making them rotate in opposite directions. “The idea was to increase the energy output of the vertical turbines while simultaneously eliminating the increased torsional forces and the inherent problems associated with upscaling traditional HAWTs for increased energy outputs,” company spokesperson Elsbeth Tronstad told me via email. Knutsen looked for scientists to test the possibilities and finally met Hans Bernhoff, a professor at the department of electrical engineering at Uppsala University, in Sweden.
According to the company, Bernhoff had been doing research on vertical wind turbines for more than 20 years, building his own 200 kilowatt (kW), 131-foot-high vertical turbine that was functional for a decade. He was intrigued by Knutsen’s theoretical model and joined the company, developing the idea of the large tilted offshore floating turbine that World Wide Wind is now working on.
HOW IT WORKS
Each rotor has three blades that sweep in an inverted conical area thanks to its V-shape (which remind me of the arms of a mechanical tree). The upper turbine is connected to an inner shaft that serves as the rotor in the electric generator. The lower turbine acts as the stator, the part of the generator that contains the coils and remains static in most generators. In this case, however, the stator moves on the opposite side of the rotor. The result: It doubles the relative speed of the shafts and thus the electrical generating capacity of the system.
Their engineers point out that the generator is not at the top of the mast, like that of a conventional HAWT system. but at the base, next to the ballast and all the other electrical system components, including the cables that connect it to shore. The added weight contributes to the stability of the system, ensuring that the tower does not capsize no matter how much the ocean heaves. This design, they say, also makes it more resistant to the vibration that greatly affects the integrity of HAWT systems, especially under very strong wind conditions.