Negative impacts of wind energy

Erosions
Erosion can be a concern in certain habitats such as the desert, where a hard-packed soil surface must be disturbed to install wind turbines. Erosion has also been raised as a concern in the eastern U.S., where wind farms typically must be installed on mountain ridgelines.
Solution: Standard engineering practices used by ski areas on the same kind of terrain are adequate to deal with any erosion issues that might be raised by construction of a wind farm and its service road.
Birds and bats kills
Birds occasionally collide with wind turbines, as they do with other tall structures such as buildings. Avian deaths have become a concern at Altamont Pass in California, which is an area of extensive wind development and also high year-round raptor use.
Solution: Wind’s overall impacts on birds are low compared with other human-related sources of avian mortality—see "Avian Collisions With Wind Turbines," for more information.
Affect lives of wild animals
Wind energy can also have negative impact on other wildlife by fragmenting habitat, both through installation and operation of wind turbines themselves. Also, the roads and power lines that are built will do harm to those wild animals.
Solution: This has been raised as an issue in areas with unbroken stretches of forests. More research is needed to better understand these impacts.
Noise
During early times, noise was a serious problem with wind turbine designs as it disturbed people who lived nearby a lot, but it has been largely eliminated as a problem through improved engineering and through appropriate use of setbacks from nearby residences.
Solution: Aerodynamic noise has been reduced by changing the thickness of the blades' trailing edges and by making machines "upwind" rather than "downwind" so that the wind hits the rotor blades first, then the tower
Shadow flicker
Shadow Flicker is often raised as an issue by close neighbors of wind farm projects. A wind turbine's moving blades can cast a moving shadow on a nearby residence, depending on the time of the year (which determines how low the sun is in the sky) and time of day.
Solution: A bit of careful planning, and the use of good software to plan your wind turbine site can help you resolve this problem, however. If you know where the potential flicker effect is of a certain size, you may be able to place the turbines to avoid any major inconvenience for the neighbors.

http://www.awea.org
American wind energy association

(Yeqi)