Wind power is an indirect form of solar power due to the fact that the land, sea and atmosphere all heat up at different rates because of solar radiation. This causes differences in air pressure, therefore resulting winds are created.
Wind power operates by producing mechanical power from the energy in the wind; this energy is converted into electricity through the use of wind turbines. The most common method to get energy from the wind is by setting up a wind farm: although domestic turbines are available and can be used to provide small amounts of electricity to individual dwellings.
Wind energy is an extremely useful resource because it is plentiful, renewable, widely distributed and clean.
The process of converting wind energy into electricity is relatively simple:
- A turbine will generally consist of 3 blades that rotate 10-30 times/minute
- The wind forces the blades the rotate
- As the blades rotate a shaft inside the turbine, which is connected to a generator, will spin therefore producing electricity.
As with all renewable energy sources there are advantages and disadvantages.
The advantages are:
- An infinite source of energy
- Produces no chemical emissions
- The ground surrounding the turbine can still be used for agricultural purposes i.e. grazing sheep
- If the turbine is taken down there will be no environmental damage or residue left behind.
The disadvantages are:
- Concerns that the turbine will ruin the look of the landscape
- Wind farms require a lot of space to produce the same amount of electricity as other methods such as coal-fire powered stations
- Can be costly to maintain
- Flicker effect
- Planning considerations
The power output of a turbine is dependent on the size of the area swept by the blades, therefore there are some necessary factors that need to be considered if wind power is to be fully utilised. For obvious reason the site needs to be windy: and it must be free from obstructions such as buildings and pylons. Another factor that needs to be considered is the migration path of birds; a turbine must be placed so that it will not interfere with local wildlife.
Wind speeds increase at a rapid rate above the ground; so turbines must be built at a safe height, but still high enough to harness as much of the winds energy as possible.
Domestic size turbines are available from numerous sources, and can be used to generate small amounts of energy for individual dwellings. These turbines range in size from 1 kilowatt to 5 kilowatts, and grants are available for installations.