*What are the advantages of wind-generated electricity?
*How does a wind turbine make electricity?
*How much of the time do wind turbines produce electricity?
*How long do wind turbines last?
*How strong does the wind have to blow for the wind turbines to work?
*What happens when the wind stops blowing?
*Could I put a turbine in my garden or on the roof of my house?
*How many turbines to power a household or farm?
*Are wind turbines noisy?
*What about electrical interference?
*Are there problems facing wind power?
What are the advantages of wind-generated electricity?
Numerous public opinion surveys have consistently shown that the public prefers wind and other renewable energy forms over conventional sources of generation. Wind energy is a free, renewable resource, so no matter how much is used today, there will still be the same supply in the future. Wind energy is also a source of clean, non-polluting, electricity. Back to Top
How does a wind turbine make electricity?
The simplest way to think about this is to imagine that a wind turbine works in exactly the opposite way to a fan. Instead of using electricity to make wind, like a fan, turbines use the wind to make electricity. Almost all wind turbines producing electricity consist of rotor blades, which rotate around a horizontal hub. The hub is connected to a gearbox and generator, which are located inside the nacelle. The nacelle is the large part at the top of the tower where all the electrical components are located. Most wind turbines have three blades, which face into the wind. The wind turns the blades around, this spins the shaft, which connects to a generator, and this is where the electricity is made. A generator is a machine that produces electrical energy from mechanical energy, as opposed to an electric motor, which does the opposite. Back to Top
How much of the time do wind turbines produce electricity?
A modern wind turbine produces electricity 70-85% of the time, but it generates different outputs depending on wind speed. Over the course of a year, it will generate about 40% of the theoretical maximum output. This is known as its load factor. Back to Top
How long do wind turbines last?
A wind turbine typically lasts around 15-20 years. During this time, as with a car, some parts may need replacing. Back to Top
How strong does the wind have to blow for the wind turbines to work?
Wind turbines start operating at wind speeds of 3 to 5 m/s and reach maximum power output between 7 to 15 m/s. Back to Top
What happens when the wind stops blowing?
When the wind stops blowing, electricity continues to be provided by other forms of generation in an isolated system (e.g. batteries, diesel generator), and by the grid in a grid-connected system. Consequently, it is possible to have at least 10% to 20% of the country's electrical demand met by intermittent energy sources such as wind energy, without having to make any significant changes to the way the system operates. Back to Top
Could I put a turbine in my garden or on the roof of my house?
More and more householders, communities and small businesses are interested in generating their own electricity by using small-scale wind turbines, either on their roofs or in their back gardens. Back to Top
How many turbines to power a household or farm?
For a home or farm, one turbine is normally installed. The turbine's size is chosen to meet the energy requirements given the available wind resource. Back to Top
Are wind turbines noisy?
The evolution of wind technology over the past decade has rendered mechanical noise from turbines almost undetectable, with the main sound being the aerodynamic swoosh of the blades passing the tower. There are strict guidelines on wind turbines and noise emissions to ensure the protection of residential amenity. It is possible to stand underneath a turbine and hold a conversation without having to raise your voice. As wind speed rises, the noise of the wind masks the noise made by wind turbines. Back to Top
What about electrical interference?
Small wind turbines are unlikely to have any detrimental effects on aviation and associated radar or navigation systems. In general, turbines with small diameters are unlikely to have effects on television and radio reception. If this occurs it is likely to be highly localised and technically easy to overcome. It is also unlikely that small rooftop wind turbines will effect either mobile phone reception or fixed radio or microwave communications links. Back to Top
Are there problems facing wind power?
The major challenge to using wind as a source of power is that it is intermittent and it does not always blow when electricity is needed. Wind cannot be stored (unless batteries are used); and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities). Finally, wind resource development may compete with other uses for the land and those alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming. Although wind power plants have relatively little impact on the environment compared to other conventional power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and sometimes birds have been killed by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants. Avian mortality remains an issue to be better understood and resolved.Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being the site preparation and installation. If wind-generating systems are compared with fossil-fueled systems on a "life-cycle" cost basis (counting fuel and operating expenses for the life of the generator), however; wind costs are much more competitive with other generating technologies because there is no fuel to purchase and minimal operating expenses. Back to Top