The wind is a free energy resource, until governments put a tax on it, but the wind is also a very unpredictable and an unreliable source of energy as it is constantly changing in both strength and direction. To produce useful amounts of power, wind turbines generally need to be large and tall, but to work efficiently they also need to be well designed and engineered which makes them expensive too.

Most wind turbines designed for the production of electricity have consisted of a two or three bladed propeller rotating around a horizontal axis. It’s obvious to say that these propeller like wind turbine blade designs convert the energy of the wind into usable shaft power called torque. This is achieved by extracting the energy from the wind by slowing it down or decelerating the wind as it passes over the blades. The forces which decelerate the wind are equal and opposite to the thrust type lifting forces which rotates the blades.

Just like an aeroplane wing, wind turbine blades work by generating lift due to their curved shape. The side with the most curve generates low air pressure while high pressure air beneath pushes on the other side of the blade shaped aerofoil. The net result is a lifting force perpendicular to the direction of flow of the air over the turbines blade. The trick here is to design the rotor blade in such a way as to create the right amount of rotor blade lift and thrust producing optimum deceleration of the air and therefore better blade efficiency.