Vertical Axis Wind Turbine May Add To Performance, Sustainable Development

Guangdong Yatu Industry Investment Company (GYII) has been working on renewable energy since 2006, and manufactured its first 750KW conventional (or horizontal axis) wind-powered electrical generation turbine in 2007.

Now the company has compiled 33 patents and thousands of hours of advanced design and engineering work in support of an advanced concept for a vertical axis wind-powered turbine.

The difference is significant. Horizontal axis wind turbines are what you see along the highways in certain areas of the nation. They consist of tall towers supporting large rotors that spin like an airplane propeller. But these designs have inherent limitations and problems. For example, horizontal axis wind turbines (HAWT) require those tall towers to support blades up to 45 meters long. These components are difficult and expensive to transport, which is why transportation can now eat up as much as 20% of a wind turbine's equipment costs.

In addition, these tall HAWTs are expensive to install, requiring heavy, large cranes. To support the heavy blades, gearbox, and generator, the tall towers must also be very strong and heavy, further adding to the overall expense.

A more subtle problem emerges when the turbine is allowed to spin: each windmill creates a "wind shadow" that carries turbulence downwind toward other windmills in the array. Whenever a windmill's blade passes through this "wind shadow" from an adjacent windmill, the turbulence induces stresses and forces that lead to fatigue and ultimately structural failure. To reduce this fatigue from wake turbulence, arrays of HAWTs are usually spread out so they stand at least 5 rotor diameters away from each other.

And because the HAWTs point only in one direction at a time, they require yaw control mechanisms to turn the axis so the blades and generator nacelle point toward the wind.

GYII's vertical axis turbine (VAWT) design eliminates or minimizes all of these problems, and more, to be exceptionally efficient.

For one thing, VAWT designs take advantage of wind power coming from all 360 degrees, all at once, and some variations on the basic design can gain extra powered from wind that blows from the top to the bottom or from the bottom to the top of the vertical axis. Because of this inherent versatility, VAWT designs are likely to prove ideal not only for high-wind areas, but also for situations where wind conditions are relatively inconsistent.

At first, GYII concentrated on designing multi-tower, high-power VAWTs to take advantage of various geophysical phenomena that influence the power of wind. More recently, however, the company has discovered that multiple electrical generating systems can be "stacked" on a single vertical axis.

By stacking several generating systems onto one vertical turbine, these advanced VAWT systems can generate 2 to 5 times more power at significantly reduced costs, compared with coventional HAWT designs.

More later ...

Photo credit: GYII