Wind is the movement of air masses as a result of temperature fluctuations and the resulting pressure differences in the atmosphere. Solar radiation and the earth’s rotation are the mechanisms driving this phenomenon. Wind occurs at different strengths, from gusts to tornadoes. Wind energy has been used throughout human history – in the form of sailing vessels (3,500 years BCE) and windmills (1,700 years BCE), Today wind is one of the most effective renewable, carbon-dioxide-free energy sources. The photo shows a windsock, which is used to measure the wind on land. Information and ideas: The photo is a good way to visualize the renewable energy source of the wind, and it can be used as introduction or for illustration. Information on the use of wind power can be found in the information module “How a wind power plant works and in the graphic “Wind turbine – inside view and elsewhere.