Frequently Asked Questions

We have listed below some often asked questions about wind turbines but should you have any further questions please just contact us.

Are wind turbines noisy?

Wind turbines are not noisy. The evolution of wind farm 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. Why not visit a wind farm and experience it for yourself?

Do wind turbines frighten livestock?

Wind farming is popular with farmers, because their land can continue to be used for growing crops or grazing livestock. Sheep, cows and horses are not disturbed by wind turbines.

The first wind farm built in the UK, Delabole, has an adjacent stud farm and riding school.

How popular is wind energy?

Wind energy is one of the most popular energy technologies. Opinion surveys regularly show that just over eight out of ten people are in favour of wind energy, and less than one in ten (around 5%) are against it. The rest are undecided.

How safe is wind energy?

Wind energy is one of the safest energy technologies. It is a matter of record that no member of the public has ever been injured during the normal operation of a wind turbine, with over 25 years operating experience and with more than 70,000 machines installed around the world.

What are wind turbines made of?

The towers are mostly tubular and made of steel, generally painted light grey. The blades are made of glass-fibre reinforced polyester or wood-epoxy. They are light grey because this is the colour which is most inconspicuous under most lighting conditions. The finish is matt, to reduce reflected light.

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 round, 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.

How strong does the wind have to blow for the wind turbines to work?

Wind turbines start operating at wind speeds of 4 to 5 metres per second (around 10 miles an hour) and reach maximum power output at around 15 metres/second (around 33 miles per hour). At very high wind speeds, i.e. gale force winds, (25 metres/second, 50+ miles/hour) wind turbines shut down.

How long do wind turbines last?

A wind turbine typically lasts around 20-25 years. During this time, as with a car, some parts may need replacing.

Why do some wind turbines have two whilst others have three blades?

The majority of modern wind turbines have three blades, as this design has been found to have a greater aesthetic appeal. The disadvantage is that each blade will add to the overall cost and weight and can be more difficult to install, particularly offshore.

Two bladed machines are cheaper and lighter, with higher running speeds, which reduces the cost of the gearbox, and they are easier to install. However two bladed machines can be noisier and are not as visually attractive, appearing 'jerky' when they turn. The engineering ideal would be to have only one blade, and some one bladed early prototypes were developed, but didn't stand the test of time.

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 dependent on wind speed. Over the course of a year, it will generate about 30% of the theoretical maximum output. This is known as its load factor. The load factor of conventional power stations is on average 50%.