What are Windmills?
Windmills harness the movement of the wind to generate useful energy. The earliest windmills had large ‘sails’ which they used to trap wind and to turn a central wheel. This in its turn could turn a grinding mechanism for corn or wheat, turning it into flour.
Modern windmills have the same basic structure in that they consist of sails rotating and elevated on a central stem in locations that are nice and windy. But, they contain electrical components that transform wind energy straight into electrical energy.
Green and sustainable, windmills (or wind turbines as they are also known) are a good source of renewable energy that does not contribute to climate change.
Windmills have captured the imagination of humans for centuries. They feature in the paintings of Van Gogh, for example, but also in the writings of Cervantes, author of Don Quijote (whose eponymous hero famously launches into battle with a group of windmills, believing them to be giants).
How windmills work ?
You can pretty much guess how windmills work by looking at the name: they use the motion of the wind to turn a central ‘mill’. However, there are some finer distinctions to make here: windmills can be divided into two different categories:
- Traditional windmills and
- Electric wind turbines – each of which works in a slightly different way.
Let’s take a look at each of these types of windmill to see how they work.
How traditional windmills work?
Traditional windmills consist of a set of rotating ‘sails’ attached to a wheel which are pushed round and round in a circle by the motion of the wind. These sails need to be elevated somehow so that they can capture the best of the wind, and this means that windmills usually take the form of a pillar or similar structure for elevating the sails. As they move, the sails turn a central spindle which in its turn moves a mill stone or pump. Traditionally, windmills were used as an effortless mechanism for grinding corn or wheat into flour – something that, when done by human hands, or by means of a treadmill for long suffering humans or animals such as donkeys or horses, can be really hard work.
This traditional windmill design started way back in ancient Babylonia and Alexandria. The earliest mechanical windmills rotated on a horizontal plane like a helicopter, however after some centuries had passed, engineers began to favour windmills that rotated in a vertical plane – like the classic windmills that you will see often on picture postcards from Amsterdam. This design on a vertical plane most probably originated in the Middle East as well.
How electric wind turbines work?
Look out of the window as you take a train or drive a car through the countryside or past the sea shore and you may well see a wind farm which consists of several electric wind turbines. These turbines mimic the design of a traditional windmill – they have a central pole atop which you can see a set of rotating blades. These blades turn when the wind blows and this turns kinetic energy (which means energy relating to movement) into electric energy by means of a conversion mechanism inside. By this means, they can harness the sustainable, renewable source of energy that is the wind and turn it into electrical energy which can be used for anything that we desire, from providing light and heating to the community to powering industrial machinery. Wind turbines are self regulating and self powering, too, as they use a small percentage of the electrical energy that they generate in order to produce the energy needed to keep their circuits working.
The wonderful world of windmills.
Fascinating and useful, windmills are an ancient structure that could nevertheless provide us with a greener way to generate energy for the human race in the present and future. Both traditional mechanical windmills and electric wind turbines are in use throughout the world in the present day.
Also read: Uses of Windmills