The Norwegian world wide wind has a radically different approach to offshore wind energy. It is based on a system of vertical-axis floating wind turbines (VAWTs) featuring two sets of blades oriented in opposite directions, which promise to produce more than double the energy of today's largest turbines.
With VAWT turbines using the same principle, they have been testing in Japan for almost 3 years systems for obtaining energy from typhoons.
Bringing wind farms into the open sea, "off shore", certainly helps to make them less intrusive and more scalable. As the ocean gets deeper, however, traditional horizontal-axis wind turbines (HAWTs) start to make less and less sense. HAWTs must hold many heavy components (gearboxes, generators, huge blades, etc.) on top of a long pole. Mounting everything on tip-proof floating platforms is a huge challenge (not to mention the maintenance costs of a turbine so far from land).
VAWT, the wind boundary is widening
Given the problems of traditional turbines, more and more engineers and operators in the energy sector they believe that VAWT turbines could be much more efficient.
Their blades extend upward, sure, but all the other heavy parts are at the base. For those who remember the game, I'm almost like one of those Subbuteo players who always stay up.
If you then consider that they can capture wind energy from any direction, you will understand that it is possible to place many of them next to each other. Although individually they are less efficient than a normal three-bladed HAWT turbine, combined in certain scenarios VAWTs can do much, much more than traditional systems.
How is the World Wide Wind system made?
The Norwegian company has proposed a completely new type of floating VAWT, designed specifically for offshore installation and massive scalability.
In fact, these are two VAWTs in one: the lower one is fixed to the outer casing of the wind tower, and is set to rotate in one direction, while the upper one is mounted on a shaft that runs right down the center of the tower and is set to rotate in the opposite direction.
The company calls this system vertical counter-rotating turbine, or CRVT.
Again, the heaviest parts and those that require more maintenance are located at the bottom. And just like a Subbuteo player, this “double VAWT” system isn't designed to always stand perfectly straight: these massive towers will tilt in the wind, which will help them resist violent gusts and damaging vibrations.
How many VAWT turbines will you need?
We are not hiding: to get the best from wind energy, important numbers are needed. To give you an idea, the largest wind turbine in the world is mammoth MingYang Smart Energy. It is 242 meters high and has a nominal capacity of 16 MW.
For World Wide Wind this VAWT project is much easier to climb, and could reach the monstrous height of 400m, with a capacity of 40 megawatts per unit.
What about the costs? Company representatives estimate a Levelized Cost of Energy (LCoE) of less than $50 per megawatt. That's less than half the LCoE of traditional, best-performing offshore wind projects due to go live in 2027.
And the World Wide Wind system? The company is working to accelerate the development of the CRVT through rapid prototyping. The goal is to have a 3 MW model in operation by 2026, and the large 40 MW machine in 2029.
Will it work? It's hard to tell
The startup does not provide any supporting research or testing on microscale prototypes. Since all VAWT blades are subjected to strong forces from every angle, I wonder what their longevity will be.
How would you replace the gigantic bearings needed to support and spin a 400 meter long shaft inside a 400 meter long counter-rotating tube? And with the mass tilted off-center most of the time, too. And immersed in sea water for decades.
Doubts destined to remain until new updates
I hope to be able to update you as soon as possible, as soon as World Wide Wind provides more data on its VAWT turbines and its CRVT system.
As with all clean energy projects, though, I desperately want to believe in them. Expanding and simultaneously decarbonizing the world's energy networks is a pulse-pounding undertaking. We have already lost the battle to contain the increase in temperature, but we absolutely must avoid worse troubles, or we will have huge disasters and billions of people on the run like climate refugees.
Gigantic 40 megawatt offshore coaxial towers at lower cost could make a huge contribution to the next century's existential battle. You don't need renderings, diagrams and promises, but tangible results.
And they are needed now.
