frequently asked questions about Wind Energy

Q: How do I tell if I have enough wind to use a small wind turbine?

A: The best place to start is with a regional wind map.  This can show you typical annual wind speeds for your area.  You will need a minimum average wind speed of 10 miles per hour for a small turbine to be viable. See our Wind Maps section for more on this.  You can also use a device called an anemometer to measure wind speed.  But keep in mind that the wind speed at ground level will be much slower then wind speed at the top of the tower where your turbine will be. 

Q. What do I do on days when the wind isn't blowing?

A: If you have a grid-connected system then you don't need to worry about it.  You would simply use the energy off of the electrical grid until the wind starts blowing again.  If you are off of the grid then you have several options. The most common approach is to use a battery bank to store the energy the wind turbine is creating. You could also use a backup generator. Yet another option is to use a hybrid system using solar panels.  One of the great things about this type of approach is that on the days when the wind is not blowing it is usually sunny. The two approaches to generating energy compliment each other.

Q: Are wind turbines noisy?

A: Despite what many people believe wind turbines are not particularly noisy. Modern residential wind turbine designs have eliminated most of the noise by going to direct drive generators which have few moving parts. Most of the sound is aerodynamic noise caused by the blades passing through the air. While this will generate some noise it is usually not much more than the noise generated by the wind itself.

Q: How big a wind turbine will I need to power my home?

A: This depends upon a number of factors, the most critical being the amount of energy you normally consume. If you use around 800 kilowatt hours per month then you would need a wind turbine in the range of 5-15 kilowatts assuming you have acceptable wind speed.

Q: What happens if we get a really high wind?  Could it break the wind turbine?

A: Modern wind turbines have special features which are designed to handle excessively high winds.  Wind turbines have a wind cut-out speed.  If this speed is exceeded the turbine will take action to prevent damage to the turbine. There are a number of approaches to doing this.  In some machines an automatic brake is activated by a wind speed sensor. Some machines twist or "pitch" the blades to spill the wind. Still others use "spoilers," drag flaps mounted on the blades or the hub which are automatically activated by high rotor rpm's, or mechanically activated by a spring loaded device which turns the machine sideways to the wind stream. Normal wind turbine operation usually resumes when the wind drops back to a safe level.

Q: How Do Small Wind Systems Affect Property Values?

A: Most research on this subject has tended to show that residential wind turbines tend to increase, not decrease property values.  They also do not appear to diminish property values for nearby residents. A 2002 survey of 300 California homeowners, conducted for the California Energy Commission by a market research firm, found that 50% of homeowners surveyed "would be willing to pay more for a home equipped with solar and wind technology."

Q: How long will it take for the wind turbine to pay for itself in energy savings?

A: The time to recoup the investment depends upon a number of factor including the cost of electricity in your area, the local wind speed, turbine size, and the nature of state and federal incentives.  Most current wind turbine users have been able to recoup their investment in 6 to 15 years. Wind turbines require minimal maintenance and will last anywhere from 20 to 30 years.

Q: Do Small Wind Systems Kill Birds?

A: Birds can collide with any number of man-made structures including wind turbines.  However, keep in mind that for every wind turbine out there you will find thousands of telephone poles which have about the same level of risk. Most bird collisions are from moving vehicles. Reports of residential-scale wind turbines killing birds are very rare.

Q: How much space will I need in order to have a wind tower?

A: Very small wind turbines can be placed close to your home but will not generate a great deal of electricity. If you are going to put up a tower you will probably want to have at least an acre of land for it.

Q: Could I mount the wind turbine on my roof instead of having to put up a tower?

A: As a general rule wind turbines should not be mounted on homes because the vibration from the turbine could be transferred to the building and damage both the mounting and the building.  In addition most turbines need to be mounted higher than the typical roof in order to get good wind speed and avoid turbulence.

Q: How much electricity can one wind turbine generate?

A: Wind turbines being manufactured now have power ratings ranging from 250 watts to 5 megawatts (MW). Example: A 10-kW wind turbine can generate about 10,000 kilowatt hours annually at a site with wind speeds averaging 12 miles per hour, or about enough to power a typical household.

Q: How much does a wind system cost?

A: A small turbine can cost anywhere from $6,000 to $22,000 installed, depending upon its size, features and service agreements.  However, most states provide tax breaks and other incentives which can help to reduce the cost.

Q: Will I have to perform much maintenance?

A: Most small turbines have very few moving parts and do not usually require significant maintenance. They are designed for a long life (up to 20 years) and operate completely automatically. It is a good idea to inspect your wind turbine once per year to look for any damage from wind born particles or excessive wear.  Rather than climb a tower you may want to arrange to have your supplier do this as part of your service agreement.