Man has used wind power for centuries with varying degrees of success: school children are well acquainted with Dutch windmills. But they may be unaware that the Germans, Swedes and Danes were also among the world's early users of wind-powered electricity.
The price and supply of fossil fuels worry North Americans less than Europeans as the latter rely heavily on imported oil. It is therefore much more a way of life to conserve electrical energy in Europe than in the US.
Now, certain places like King Mountain in West Texas are seriously considering electrical energy conservation. There are 214 wind turbines installed in Texas to give 278 million Watts (278MW) of power – that is enough for 80,000 really huge Texan homes (or 3% of Denmark's entire electricity requirement). Such installations show what wind power has to offer.
Home-Sized Wind Turbines
There are many wind turbine system manufacturers today and reconditioned or used systems (before the grid came along in the early 1900s) are also available.
The most common question on seeing a wind turbine is "How big is it?" This is the wrong question to ask: turbines are about more than the tower's height or the amount of electricity.
Wind turbines need a more refined assessment to decide the right size than PV modules. Let's try to understand one unit's design and function.
Most homes use horizontal-axis wind turbines with brand-name main components. A wind turbine requires a tower structure to support it; the higher the tower, the greater the wind power. Usually, towers are between 60ft and 100ft tall (18-30 m). They can be either self-supporting or have cheap guy wires to support them.
The tower is placed in a concrete pad which takes the weight of the tower as well as preventing any sideways skidding. Guy wires give all the necessary support with anchors securing them to the ground or concrete foundations. Every guy wire has cable tensioning devices to eliminate slack and tower movement.
The wind turbine's central rotor and blade components are very important to a system where the generator/alternator is placed on the inside. The rotor has a nose cone which causes the wind to flow smoothly over the blades. The nacelle is a protective cover for the generator against adverse weather conditions. A tail vane component keeps the rotor and blade pointed towards the wind. Some models use the tail vane to slow down the blades during high winds through an automatic or manual function called furling; this feature allows the unit to shut down when the weather is too adverse.
A small 1,000W turbine system's rotor component with the blades removed from their sockets allows you to see the generator wiring at the rotor's rear; this leads to a black box called the rectifier bridge which converts AC to DC for the battery bank. The AC is a 3-phase supply at the rectifier's top. This gets connected to the tower assembly. The spinning turbine at the tower's top would twist the power cables down the tower to the house: this is prevented by wiring