Wind power is generated by moving air. As the sun heats the land, the air above also warms and rises. Cold air then replaces the rising air. This creates the winds that we feel most days of the year. The diagram below shows how this ‘system’ works.
Air tends to warm at a faster rate over land because the land retains its heat. Over the sea the air warms more slowly as heat by the sun is slowly cooled by the cold water. If you visit the seaside or coastal area you will probably find that the weather is more breezy or windy than inland. This is because the warm air rises over the land and cold air over the sea replaces it.

Throughout history people have taken advantage of the power of wind. Sail vessels have been used to travel along and across rivers, seas and lakes. For example, the Vikings used long ships with sail from Europe to England, Scotland, Wales and Ireland. It is also believed that they travelled even as far as North America, all through the use of wind power.
It is also known that the Chinese over 1500 years ago had large sailing vessels and travelled as far as Africa.
It is difficult to think of a time when people have not made great use of the power of the wind.