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Wind Power
Frequently Asked Questions

1. How do wind turbines work?
2. Will a wind turbine help the environment?
3. How much money will a wind turbine save?
4. Are wind turbines safe?
5. Do wind turbines kill birds?
6. Do wind turbines make noise or interfere with electronic devices?


1. How do wind turbines work?

A wind turbine, which is installed on top of a tower, collects kinetic energy from the wind and converts it to electricity that is compatible with a building's electrical system.

In a normal small-scale application, a building is served simultaneously by the wind turbine and a local utility. Generally, if the wind speeds are below 7 mph there will be no output from the turbine and all of the needed power is purchased from the utility. As wind speeds increase, turbine output increases and the amount of power purchased from the utility is proportionately decreased. When the turbine produces more power than the facility needs, the extra electricity is sold to the utility. All of this is done automatically. There are no batteries in a modern wind system.

2. Will a wind turbine help the environment?

Yes. Wind turbines produce no pollution. Wind power offsets pollution that would have been generated by a utility company. Over the course of a year, a 100 kw wind turbine can offset approximately 76 tons of greenhouse gases (carbon dioxide and other gases which cause global warming).

3. How much money will a wind turbine save?

A wind turbine can reduce energy costs by 50% to 90% for an average household 10-30% for larger buildings. The exact amount of money a small wind turbine saves in the long run will depend upon its cost, the amount of electricity used, the average wind speed at the site, and other factors.

A wind system will usually recoup its investment through utility savings within 6 to 15 years and after that the electricity it produces will be virtually free. Over the long term, a wind turbine is a good investment because it insulates property owners against unpredictable rising energy costs.

4. Are wind turbines safe?

Falling tower: Over 2000 wind turbines are installed in the U.S., and their safety track record is excellent. Trees are much more likely to fall than a properly installed wind turbine, but no setbacks or minimum property sizes are required for trees.

Safety of utility repair personnel during a power outage: Small wind systems shut down automatically in the event of a power outage, and will not energize a dead power line.

Ice throw from rotor blades: Ice buildup makes wind turbine blades less aerodynamic, so that they turn more slowly, making only a few revolutions per minute. Ice will melt and drop to the base of the turbine tower so there is no risk of the ice being thrown.

More reading: http://www.awea.org/smallwind/toolbox/TOOLS/fs_safety.asp

5. Do wind turbines kill birds?

While no studies have been done of this question, anecdotal evidence indicates that birds occasionally collide with small wind turbines, as they do with any other type of structure. However, such events are rare and very unlikely to have any impact on bird populations. House cats in the U.S., by contrast, are estimated to kill roughly one billion birds each year. Statistically, a single house cat is a much greater threat to birds than a small wind turbine.

6. Do wind turbines make noise or interfere with electronic devices?

Small wind turbines are usually barely audible above other ambient noise. A 100 kw small wind system registers about 56 decibels 140 feet away - about the noise level of a quiet restaurant interior.

Most modern windmill blades are made of fiberglass or other composite materials which do not interfere with electronic devices.

More reading: http://www.awea.org/smallwind/toolbox/TOOLS/fs_noise.asp

Source: American Wind Energy Association, www.awea.org