Vertical or horizontal wind turbine comparison

What works better?

There is no difference between the lift effect over an upright wing or a wing lying flat. There are big differences when that wing goes around, though. The horizontal axis of rotation then gives the advantage of constant airflow. With an upright axis of rotation, the wind is constantly changing. That makes a vertical axis wind turbine more complicated.

The flag turbine and a horizontal axis wind turbine in 1 shot.

Click on the image for the video

But what works better? Complex systems can function well, and perhaps even better, than simple systems. Writing with pen and paper is easier than memory storage in computer chips ;-).

For a properly functioning wind turbine, 3 aspects are important;

1. A lift force must be generated by the blades
2. The drag of the blades must be minimal
3. The lift forces must be perpendicular to the turbine axis to generate torque

In the FLAG TURBINE, these 3 aspects are optimally realized. The large blaeds provides high lift forces. The variable pitch mechanism ensures proper direction of force. The placement on a long arm provides high torque, and the low speed ensures low drag.

All other turbines direct the lift forces by velocity vectoring. Since the rotational speed must be faster than the wind speed for this to happen, the lift force is lower and the drag is higher.

A vertical axis wind turbine, with variable blade pitching, such as the flag turbine, is therefore the best functioning wind turbine.