Technologies for wind energy use .
Types of technologies
Wind technologies use energy of air masses over the earth surface, that a consequence of the movement, caused by the Solar heat and the movement of the Earth. Air moves the propellers of the wind energy device as a result of the power, that is generated as a result of the difference in the pressure, on the flat surface of the propellers and the low pressure of their opposite site. Their rotation causes direct production of mechanical energy, that can be transformed into electric with the help of electric generator.
Small wind turbines are generally used to generate energy for charging accumulator batteries, that have different application, for example in a remote part of a farm, where it would cost a lot to be connected to the grid. Typical appliances are electric fences for livestock, small electric pumps, and the security system. Standard sizes for wind generators are 50wwith diameter of rotor about 900mm.They can easily be installed without any help from a specialist. The bigger generators for self-standing systems have a capacity of 1 to 10 KW and they are used to supply energy to sites, that are away from the grid.
Systems connected to the grid
In these systems energy , produced by the wind turbine is directly submitted to the grid. They are separate wind generators, or whole wind farms, with power of generators from 50 up to 2000kW.
Can I apply that technology in my enterprise?
The main questions, you should answer at are:
Is there wind potential in the region, where your SME is located?
The answer of this question is given by “Wind energy audit” of specialists.
But before you contact them you can make a conclusion by yourself, as you check data about speed and direction of wind in the nearest meteorological station, as you see landscape features(gorges, hills,) proximity to big water basins(seas, oceans, ) and local features- lying in one direction trees.
You can start as you check the map of winds in Europe whether your region is an appropriate place to introduce Wind energy technology.
Map of winds in Europe
Another important factor is the local winds.
Sea breeze. This is a wind, a result of the temperature difference sea-land, during the day and the night and it is monitored in an area, wide some dozens kilometers off the coast. .
Mountainous -valley winds. The reason that causes them is the same one as with the sea breeze –the temperature contrast. During the clear nights the tops of the mountains and the high hills cool up more and faster than the foot of the mountains.
The cooled and compact air descends down the ridges towards the low land. Favorable relief forms can lead up to its velocity grow up. That is why the mountain winds have different local names. The most famous wind is the one called “bora”. This is a strong cold wind, typical only for winter time. It descends down the rigid slopes towards the low places resembling a water fall but an aerial one.
“Fion” is also a kind of a mountainous wind, but it is caused by absolutely different reason. Less known is the valley wind. , that blows upwards the slopes of the hills and the mountains. It is a result of the strong heating of the mountains tops in the summer, especially of the southern ones. Air above them is getting warmer than the air in the even part at the same
height. Then arises a movement, that when there is humid air, results in clouds forming on the ridge and above the top.
How to choose size of the turbine?
The size of the turbine should correspond to your electricity demand. Wind turbines for sale in the market, have strictly described parameters and you can easily take a solution.
Example: If a wind turbine with power 50 kW , and for a year- 8760 hours is installed in a small medium size enterprise, away from the grid , electric energy production will not be 438 000 kW/h, but at the time of most favorable conditions it will be 87600kW/h.
Every negligible inaccuracy in the wind energy audit or with the choice of the appropriate turbines can result in 200% overestimate of the annual production of electricity. That sensibility towards the choice of wind energy audit and the selection of the relevant wind generator is due to the fact, that the capacity of each wind turbine depends on the third degree of the velocity of wind –etc when there is a double increase of the wind velocity, power is increased 8 times, and when it is triple- 27 times. That is why the preliminary selection of a site is a very important step for seating for each turbine , because if it is even over a small hill , with a height towards the surrounding terrain 50 meters, the velocity of the wind on the hill is 2-2,5 times higher than in an even terrain around it. Etc - over or underestimating of the annual production of electricity of a wind electric generator in the mentioned case can be between 8 up to 14 times!!!!!!!!!!!!!!!!!!!!!
N.B Bear in mind that wind is unstable energy source and the maximum mean annual energy production can reach up to 20 % of the capacity of the used turbine.