Wind Turbine Noise
Your neighbours' concerns relating to wind turbine noise are important. No matter the size of the wind turbine, the potential for turbine noise to bother other people always exists. Even if a wind turbine does not emit enough sound to violate any noise regulations, the noise it produces may still be objectionable to other people. Before building a wind turbine, familiarize yourself with the types of noise your wind turbine could make:
Aerodynamic noises may be made by the flow of air over and past the blades of the turbine. Such noises tend to increase with the speed of the rotor. For blade noise, lower blade tip speed results in lower noise levels. Of particular concern is the interaction of wind turbine blades with atmospheric turbulence, which results in a characteristic "whooshing" sound.
Mechanical noises may also be produced by components of a wind turbine. Normal wear and tear, poor component designs or lack of preventative maintenance may all be factors affecting the amount of mechanical noise produced.
Aerodynamic noises may be made by the flow of air over and past the blades of the turbine. Such noises tend to increase with the speed of the rotor. For blade noise, lower blade tip speed results in lower noise levels. Of particular concern is the interaction of wind turbine blades with atmospheric turbulence, which results in a characteristic "whooshing" sound.
Mechanical noises may also be produced by components of a wind turbine. Normal wear and tear, poor component designs or lack of preventative maintenance may all be factors affecting the amount of mechanical noise produced.
 |
| Wind turbine noise |
How Loud Might a Wind Turbine Be?
At a distance of 250 m, a typical wind turbine produces a sound pressure level of about 45 dB(A) (decibels). As following figure shows, this sound level is below the background noise level produced in a home or office. Most small wind turbines, in fact, make less noise than a residential air conditioner.
Small Wind Turbines
The blades rotate at an average range of 175-500 revolutions per minute with some as high as 1150 rpm. Large turbines turbine blades rotate in the range of at 50-15 rpm at constant speed, although an increasing number of machines operate at a variable speed.
 |
| Comparison of decibel levels from a hypothetical wind turbine (from 250 m away) with other sources of noise. |
Maintenance
A wind turbine requires periodic maintenance such as oiling and greasing, and regular safety inspections. Check bolts and electrical connections annually; tighten if necessary. Once a year check wind turbines for corrosion and the guy wires supporting the tower for proper tension.
If the turbine blades are wood, paint to protect from the elements. Apply a durable leading edge tape to protect the blades from abrasion due to dust and insects in the air. If the paint cracks or the leading edge tape tears away, the exposed wood will quickly erode. Moisture penetrating into the wood causes the rotor to become unbalanced, stressing the wind generator. Inspect wooden blades annually, and do any repairs immediately.
After 10 years, blades and bearings may need to be completely replaced. With proper installation and maintenance, your turbine can last 20-30 years or longer. Proper maintenance will also minimize the amount of mechanical noise produced by your wind turbine.
If the turbine blades are wood, paint to protect from the elements. Apply a durable leading edge tape to protect the blades from abrasion due to dust and insects in the air. If the paint cracks or the leading edge tape tears away, the exposed wood will quickly erode. Moisture penetrating into the wood causes the rotor to become unbalanced, stressing the wind generator. Inspect wooden blades annually, and do any repairs immediately.
After 10 years, blades and bearings may need to be completely replaced. With proper installation and maintenance, your turbine can last 20-30 years or longer. Proper maintenance will also minimize the amount of mechanical noise produced by your wind turbine.
 |
| Maintenance |
Safety Concerns
All wind turbines have a maximum wind speed, called the survival speed, at which they will not operate above. When winds over this maximum occur, they have an internal brake and lock to prevent them from going faster than this survival speed.
For turbines operating in cold winter conditions, be prepared to de-ice as required, and store batteries in an insulated place.
Mounting turbines on rooftops is generally not recommended unless a wind turbine is very small (1 kW of rated output or less). Wind turbines tend to vibrate and transmit the vibration to the structure on which they are mounted. As a result, turbines mounted on a rooftop could lead to both noise and structural problems with the building and rooftop.
For turbines operating in cold winter conditions, be prepared to de-ice as required, and store batteries in an insulated place.
Mounting turbines on rooftops is generally not recommended unless a wind turbine is very small (1 kW of rated output or less). Wind turbines tend to vibrate and transmit the vibration to the structure on which they are mounted. As a result, turbines mounted on a rooftop could lead to both noise and structural problems with the building and rooftop.
 |
| Safety Concerns |
Posts
0 Comments :
Post a Comment