Wind energy is a renewable source of energy that will never run out and that doesn’t have any by-products. This makes it a far superior form of energy when compared to fossil fuels which are in short supply and which are gradually contributing to the effects of global warming. As it stands, 2% of the world’s electrical energy comes from wind turbines, but a lot more wind energy is also used for other purposes – for powering sail boats and kites, for powering windmills and for operating wind pumps. Meanwhile many households are these days also using miniature wind turbines in order to power their home appliances and other utilities. Every time a company, county or household – or even boat – decides to use wind energy as opposed to fossil fuels, they are saving a huge amount of money on utility bills, and at the same time decreasing the amount of damage they do to the planet by reducing their ‘carbon footprint’.
Well essentially wind energy is kinetic energy. In other words, wind is really made from fast moving air particles and when these strike against things this is enough to transfer that kinetic energy and push propellers or lift kites. This works in the same way as tidal energy essentially then, with the propellers of wind turbines providing the same role as a hydroelectric dam.
But why are these air particles moving so fast in the first place? Well like much of the Earth’s energy, it is really the sun that is responsible. This is because the sun heats up areas of land and these areas then absorb that heat. Once they get to a certain temperature however this then causes hot air to start to rise (because hot air weighs more than cooler air – due to the fact that faster moving air particles exert more pressure). In this way, heat energy from the sun and the ground has been converted into kinetic energy in the air.
So this causes the hot air to rise, but as we know wind doesn’t just go up – it travels in various directions with some force. At the same time wind isn’t hot – so where do those cold gusts come from? Well essentially this comes from the cold air that was previously on top of that hot air – when the warmer air moves up, this leaves a void and the colder air rushes down to fill that and that’s what causes the wind that we feel on our face and in our hair. Crucially that is also what powers wind turbines and windmills.
This then gives us energy in the form of fast moving air particles, and when they collide with the rotors on a wind turbine this causes them to turn and to power the generators that utilise electromagnetic induction in order to convert that movement into electric voltage by turning a conductor (usually coiled wire) quickly between magnets, thus giving us energy that we can use in our homes or businesses for any application.