How Does A Wind Turbine Work?
Humankind has been harnessing the energy of the wind for many thousands of years. Sailing ships and boats make use of the wind’s energy to take people and cargo from one place to another, windmills have been used throughout recorded history to harness wind energy in order to turn corn into flour.
Modern wind turbines do something only slightly different from this. They are used to convert wind energy into a more convenient form, electrical energy.
So how do they work? Well, the wind turns the turbine (‘rotor’, or if you like, ‘windmill’) which then powers an electricity generator, in much the same way that a petrol or diesel engine powers a portable electricity generator. In fact, generators convert the circular movement of an axle into electricity using principles discovered by Faraday in 1831, but we need not delve too deeply into this here.
What it is, perhaps, more important to know, is the kind of wind turbines which exist, and how they perform.
A ‘turbine’, is simply anything which converts the movement of a gas or liquid, into mechanical circular movement. So a traditional windmill or waterwheel, is, in theory, a turbine.
But recently, much research work has gone into the different shapes that the turbine blades must have, in order to maximize their efficiency.
And recent studies have shown that, in a domestic situation in particular, some designs work very much better than others, by a factor of ten even. There are two basic types of ‘rotors’ and therefore of rotor blades.
Horizontal Axis Rotors
These are the traditional ‘windmill’ type. They have a propeller-like rotor, the blades are the propeller blades, usually there are three of these. This kind of rotor, when very large, is efficient for high wind levels, and, when on a small scale, efficient for domestic use.
Vertical Axis Rotors
These are the more modern ‘space-age’ type, with blades that turn about a vertical axis; the whole structure sometimes looking like a large hoop, and sometimes like a waterwheel turned sideways. Rotors of this kind, currently, are only efficient on a large scale, and where the wind is continuous but not at high speeds.
Harnessing wind power is an ancient idea which has now been brought up to date with the latest technological advances.