Frequently Asked Questions

How big are wind turbines?

- The newest wind turbines can reach as high as 150 meters at the top of the blade, but most are in the range of 100 to 120 meters. The generator and blade assemblies are mounted on top of conical steel towers that measure from 4-5 meters across the base.

How long do they last?

- Beyond 25 years and new developments are leading to life expectancies beyond 35 years.

How fast do they spin?

- The blades of most turbines installed in North America rotate at a fixed rate of between 20 and 25 revolutions per minute. Variable speed machines are being introduced that can spin from 14 to 28 revolutions per minute.

How much power do they generate?

- Each megawatt of installed wind capacity can power 200-300 average Canadian homes, depending on the strength of the wind regime where the particular turbine is located. Canada has barely begun to develop its wind potential, but has enough wind resources to supply at least 15% of its entire electricity needs. This is more than all of our nuclear facilities combined. Installing wind power can facilitate more efficient use of Canadas existing hydro resources, avoiding the need to create additional dams.

What happens when the wind doesnt blow?

- Even at the best wind sites, the wind doesnt blow all the time, and there is no wind the turbines dont produce any electricity. Turbines need wind speeds of about 4 meters per second to commence generating, and reach 100% of their rated output at about 11 meters per second. Good wind sites have average wind speeds in excess of 6.5 meters per second.

Are they noisy?

- No, this is a common misperception. Engineering tests indicate that at a distance of 400 meters, the perceived sound level of a modern turbine is less than 45 decibels, which is well below traffic noise (90 decibels) or even normal conversation (60 decibels). Beyond 500 meters, their sound is indistinguishable from normal background noise. Remember, when the air is calm and quiet they dont make any noise at all because they do not move. We offer more information at this page (link)

Do they kill birds?

- Sometimes, but with proper planning, bird mortality is very low and birds and turbines can coexist quite happily together. The blades move relatively slowly (only about 1 revolution every 3 seconds) so birds can quickly learn to avoid them by sight or sound. Studies have shown that cats, buildings and cars present more of a problem for birds than well-sited wind farms.

What about negative environmental impacts?

- Wind turbines leave a very small footprint on the environment. They displace coal and oil-fired electricity, which is the single biggest source of smog, acid rain and greenhouse gas emissions. They have a relatively small impact on wildlife and are compatible with many farming and recreational activities.

Will they fall over? Are they dangerous?

- Wind turbines are highly sophisticated machines and are built to very rigorous standards on engineered foundations. They are designed to automatically shut down at 90 kph, but can withstand winds of up to 180 kph. There have been thousands of turbines in Europe for more than two decades and no member of the public has ever been hurt or killed by a wind turbine.

What about lightning strikes?

- Like all tall structures, each turbine is electrically grounded to limit lightning damage. Any damage that does occur affects the electronics, not the structure itself.

How do turbines help the environment?

- Wind turbines symbolize ecological progress. They help to restore clean air by displacing "dirty" power sources such as coal and oil. Within 3-5 years, they produce more energy than was expended in their creation and they make zero emissions.