02/01/2014 - 01:09
Renewable Energy Development Institute - REDI

Not only is a wind turbine an inevitable part of a wind power plant, it is also the heart of its mechanism. Thanks to it, a power plant functions properly and can generate energy from a clean force of wind. Wind turbines are distinct elements of the landscape. With all their majesty, they cause awe and bring us closer to modern, ecological sources of energy.

Wind turbines, known also as wind engines turn the kinetic energy of wind into a mechanical force, namely work of rotating moves of a rotor. Engines that use fore mentioned processes can be divided into two groups: horizontal axis turbines, lateral axis turbines. The first kind is more popular and it comprises of a high tower with a rotor that looks like a helicopter rotor. Such a rotor has three rotor blades, but there may be fewer or more according to the type of a construction. To reach maximum efficiency, a turbine has to be placed in the direction of where the wind blowing, but this may differ substantially. Moreover, various turbines are pointed out when considering horizontal axis engines, due to its location on the tower. They can be located before or behind it. The latter method is applied rarely because the tower hides the rotor.

Lateral axis turbines make up for a small percentage of all wind turbines. The most distinctive models are Darrieus' turbine, invented in France and Savonius' turbine, designed in Finland. They are strictly connected with the wind conditions of an area since an engine cannot move faster than the wind is blowing. Due to its limits they are used not to generate energy, but for grinding grain or pumping water.

Energy produced in such a way has to be converted into electric energy by a special generator, called induction motor. Thanks to its existence the construction can be easily plugged into a grid, but a power converter has to have fast shaft rotation. This is because induction motors generate the most effective power when the speed of rotation is much above the rotor's rotation speed. To make the construction easier transformers can be eliminated and a generator that has alternating rotation speed connected directly to a rotor can be used. This way the velocity is smaller, thus there's less noise and the machine lasts for longer.

Wind power plants are divided into small and big, according to a turbine's size. Bigger ones are clearly visible and they can't be missed – some people like it and others don't. They make substantial noise and are dangerous to birds or bats, but they can create vast amounts of energy. Sometimes such big turbines can't be erected and in such cases smaller ones are applied. They are quieter, they don't impose any danger to animals and they are not detrimental to the landscape but may become an interesting architectonical element. Some places are also more open for smaller turbines, and their application is favourable for habitants of an area by partially satisfying demand for electric energy. Furthermore, their light and transportable construction enables erection of power plants on areas that are difficult to get to.

The worldwide wind energy market is growing annually and scores many successes. Thanks to it, there is a growth in using ecological energy – now it's about 160 GW. The USA (35.2 GW), China (26 GW), Germany (25.7 GW) and Spain (19.1 GW) are the leasers among countries that use wind turbines.

Thanks to technological development, the power of wind is the main source of alternative energy in Europe. Wind engines that are applied can all produce 142 Twh energy annually, making up 4.2% of demand of the EU. It's of paramount importance since this way 108 mln t of carbon dioxide per year don't go to the atmosphere – 50 mln cars produce so much fumes. Poland generates 472 MW of electric power by using wind turbines.

Wind turbines now play a constant part in the electricity bill. Wind is a renewable source of energy that doesn't spoil our environment and is an inexhaustible source of energy. It's worth investing in ecology, and wind energy makes it possible even for an individual user.

People are forever trying to find new sources of renewable energy, so it isn’t surprising that they are especially interested in water and its versatility. Accordingly, much effort has been directed into obtaining energy from tidal and wave power, which are defined as circular movements of water molecules caused by wind that moves water surface through friction.