noise, however, is a steady noise. The turbine makes loud noise while yawing under the changing wind direction. The local noise ordinance must be complied with. There have been cases of noise complaints reported by the nearby communities.

5.8.2Electromagnetic Interference (EMI)

Any stationary or moving structure in the proximity of a radio or TV tower interferes with the signals. The wind turbine towers, being large structures, can cause objectionable electromagnetic interference on the performance of the nearby transmitters or receivers. Additionally, rotor blades of an operating wind turbine may reflect impinging signals so that the electromagnetic signals in the neighborhood may experience interference at the blade passage frequency. The exact nature and magnitude of such EMI depend on a number of parameters. The primary parameters are the location of the wind turbine tower relative to the radio or TV tower, physical and electrical properties of the rotor blades, the signal frequency modulation scheme, and the highfrequency electromagnetic wave propagation characteristics in the local atmosphere.3

In other aspects, the visual impact of the wind farm along with the effect on the wind life can be of concern to some. The breeding and feeding patterns of the birds may be disturbed. They may even be injured and killed if they collide with the blades. Under these concerns, obtaining permission from the local planning authorities can take considerable time and effort.

References

1.Roy, S. 1997. “Optimal planning of wind energy conversion systems over an energy scenario,” IEEE Transaction on Energy Conversion, September 1997.

2.Gijs, van Kuik. 1998. “Wind turbine technology — 25 years’ progress” Wind Directions, April 1998.

3.Spera, D. A. 1994. “Wind Turbine Technology,” American Society of Mechanical Engineers, New York, 1994.

© 1999 by CRC Press LLC