As was noted in the discussion of solar energy in an earlier section of The Green Pages, energy from the sun, solar power, arrives on Earth as a mixture of heat and light. Wind is a form of solar energy because it is caused by differences in air temperature, which result from uneven heating of the atmosphere by the sun. The spinning of the earth, the physical features of the land and large bodies of water also affect wind flow patterns.

In the case of a wind turbine, sails or blades are used to convert the kinetic energy of wind into electrical energy. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.

The turning blades turn a shaft inside the box at the top of the turbine called a nacelle. The shaft goes into a gearbox, which increases the rotation speed for the generator. The generator uses magnetic fields to convert the rotational energy into electrical energy like normal power stations. The energy generated goes to a transformer, which converts the electricity to the right voltage - either for use in the home or for distribution throughout the community.

Single, small turbines below 100 kilowatts are used for homes, telecommunication dishes or water pumping. Large-scale generation of electricity uses turbines as large as several megawatts in size, which are grouped together in wind farms. They provide large amounts of electricity to the electrical power grid of a community.

In the newspaper

Symbols on the weather map in The Royal Gazette show the wind direction and speed. The arrow shows the direction, the number of feathers shows the speed (one feather for 10 knots). Look at the weather map in today's edition of The Royal Gazette. In what direction are the winds blowing today? What is the wind speed?

Diagram from British Wind Energy Association website www.bwea.com