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Wind power

The basics on windpower: what is it and how does it work?

wind turbines on a hill

Credit: iStockphoto

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What is wind power and how does it work?

Basically, wind power is a form of renewable energy, a way of generating electricity without burning fossil fuels but using the flow of air instead.

In the simplest terms, electricity is generated from wind by the kinetic energy of the air pushing the blades of a wind turbine. The mechanical energy of the blades turning is then converted into electricity by an electrical generator.

Wind turbines come in many different shapes and sizes, but there are some common features. Each turbine has several blades around a central pivot that turn around in the wind, which are connected to a generator.

What's the difference between a windmill and a wind turbine?

Both windmills and wind turbines use wind to 'do stuff.' The difference is in what they do. For example, windmills harness the movement of the wind to mechanically grind grain or pump water from underground. They do not produce electricity.

Wind turbines on the other hand, use the mechanical energy to generate electricity. That electricity may then be used to power anything electrical, or be fed straight into the national grid.

How big is a turbine?

How long is a piece of string? Small turbines a few metres in height can be installed on farm buildings. The tallest onshore turbines are manufactured by ENERCON, the tallest of which are 198 metres high!

What are wind farms?

When many wind turbines are constructed on one site, they are collectively called a wind farm. The largest wind farm in the world is the Horse Hollow Wind Energy Center in the USA where the 421 wind turbines produce over 700 MW of power. That's enough to power 220,000 homes per year.

There are more than 40 wind farms in Australia that generate one per cent of the nation's electricity supply. The largest is Lake Bonney Wind Farm which generates almost 240 MW of power from its 99 wind turbines.

Sounds great, but does wind have any disadvantages?

Well, one problem is reliability. If there's no wind, there's no power. A 2 MW wind turbine will not produce 2 MW of power unless it's windy enough.

What's more, if it's too windy, many turbines have a built-in mechanism to stop rotating and 'lock down' operation to avoid damage.

When the blades aren't turning, other sources of electricity (or electricity stored up from when the turbines were working) must be used to meet supply demand.

Can I get one installed in my backyard?

In theory, yes. However, wind power is still a relatively new technology, and as such prices are still high.

Furthermore, depending on where you live, there might not be enough wind for it to be worth it. Urban areas often don't have enough wind to power a wind turbine.

However, small wind turbines have been successfully installed on farms in rural areas, where they're often more exposed and therefore more windy. The details of some companies that currently manufacture small turbines can be found here.