World’s Tallest Vertical-Axis Wind Turbine

Here in Canada, there’s a large scale windfarm known as Le Nordais, which as well as having 133 conventional wind turbines, also features one particular design of wind turbine with which you may be unfamiliar.

Le Nordais is split between two locations, and it is at Éole Cap-Chat on the Gaspé Peninsula that we find the Cap-Chat Wind Turbine, which at 110 metres is the tallest vertical-axis wind turbine in the world.

The “vertical axis” refers to the the main rotor shaft which runs vertically. One of the benefits of this arrangement is that the generators and gearboxes can be placed close to the ground, but more importantly, that vertical-axis wind turbines (VAWT) do not need to be pointed into the wind.

The Cap-Chat turbine is actually a Darrieus wind turbine, and the reason we don’t see many of them is that despite the apparent benefits, the constantly changing direction of the forces applied to the spinning blades causes poor performance and reliability.

For these reasons Darrieus designs are no longer developed, but the torque issues were eventually solved by using a development of the Darrieus design that features a helical twist of the blades.

Great shadow though!

Official site, Ground-level pic, VAWTs on Wikipedia. Thanks to Benoit and Eric.