: :  Renewable Energy   : :  Wind Farms

Wind Turbines

The basic concept behind a wind turbine is a simple one.  Turbines mounted on to a tower capture the wind’s energy with their rotor blades (usually two or three).  By being mounted high above ground (say 30 metres or more) they are directly exposed to faster, less turbulent wind.  Each rotor blade behaves in a similar way to an airplane wing.  As the wind blows past the blade, a low-pressure air pocket forms on the downwind side of the blade.  This low-pressure air pocket will pull the blade towards it and thus the rotor will turn.  As with an airplane wing, this force is called lift and is significantly stronger than the drag force caused by the wind against the front side of the blade.  The net effect of these forces results in the propeller-like spinning of the blades.  The rotating shaft then, in turn, spins a generator and thus produces electricity.

Wind turbines can be deployed on varying scales; from residential microgeneration, to large scale wind farms used to supplement the energy grid.  These wind farms are, at times, criticised as being unsightly or noisy; this, of course, is subjective and they are considered by others as tourist attractions.  To counter negative connotations, they are often located away from residential areas, and improvements in aerodynamic design mean the noise is minimal (certainly quieter than traditional power stations).  Wind turbines have, on occasion, been known to kill birds but this is rare and they do in fact have an exemplary industrial safety record: no members of the wind industry or the public have ever been killed by a wind turbine (worldwide).  A few more advantages include: they produce no waste or greenhouse gases, need no fuel, the land beneath can normally still be used for farming, and they are a good method of supplying energy to remote areas.  Overall, the benefits of wind turbines far outweigh  the drawbacks.