The use of wind energy is a long history: how old are windmills and sailing ships? Yes, and wind power plants began to be built at the beginning of the last century. It should be noted that one of the leaders in this area in the 1930s-1950s was the Soviet Union. Back in 1931 in Crimea, near Balaklava, was put into operation wind power, which worked until 1941. During the battles for Sevastopol it was completely destroyed. The wind turbine support structure (mast) was built upon the project of Vladimir Grigorievich Shukhov. At that time the wind turbine with the wheel 30 m in diameter and the generator 100 kW was the most powerful in the world. Wind turbines in Denmark and Germany at the time had a wheel diameter of up to 24 meters, and their capacity did not exceed 50-70 kW.
Wind energy is environmentally friendly, inexhaustible energy, and, most interestingly, it is easy to use at home. To convert wind energy into electrical energy are wind power plants or wind turbines.
Wind turbines used to generate electrical energy come in different sizes, types and modifications. Large wind turbines, which are usually used in wind farms (power plants) can produce large amounts of electricity – hundreds of megawatts, which can provide hundreds of homes and dozens of land-based casinos. Small wind turbines, which produce no more than 100 kW of electricity, are used in private homes, farms, subsistence farms, etc., serve as a source of additional electricity, helping to reduce payment for the main source of electricity. Very small wind turbines, the capacity of which is 20-300 watts, are used to recharge batteries and where there is no need for a large amount of electricity.
The efficiency of a wind farm
Small wind farms will be cost effective if the following conditions are met:
- The wind at your location blows steadily and many days a year;
- your electricity costs are high;
- you are not connected to the power grid or it is far away from you.
The place where you are going to install your wind turbine is very important. It should not be placed near trees, houses – you will not get the full benefit of the wind turbine. The strength of the wind is always greater on top of hills, near the shoreline, in the steppes, in places where there are no trees and buildings. Keep in mind that trees can grow, but a wind turbine can’t.
Don’t expect your wind farm to produce enough electricity all the time. The wind speed in the same place can vary greatly and, as a consequence, the amount of electricity generated will also vary. And if the wind speed varies by 10%, the generated electricity will vary by 25%!
Types of wind turbines
There are 2 main types of wind turbines:
- Horizontal Axis Wind Turbine (HAWT – Horizontal Axis Wind Turbine) and Vertical Axis Wind Turbine (VAWT – Vertical Axis Wind Turbine). Horizontal wind turbines must always face the wind. They are designed for this purpose with a pivoting mechanism. Small wind turbines use a vane turning mechanism downwind (the so-called “tail”). There is also a mechanism for turning the blades along the wind in hurricane winds (above 25 m/sec) so that the wind turbine could carry them without losses. Mast for horizontal wind generators should be designed so that the blades do not touch the objects that may be under them. Because of the large diameter of the blades, the complexity of the mechanism of turning and a large number of mechanical joints, the service life of small horizontal wind turbines is 10-15 years. The biggest disadvantage of horizontal wind turbines is a high starting (from 3 m / sec) and nominal (11-1 5 m / sec) wind speed – this makes them ineffective for use in continental areas, where the average wind speed of 3-5 m / sec.
- Vertical wind generators work in any wind direction. They require a lower mast height because their blades are above the mast rather than above and below it. In addition, because the blades are above the mast, a vertical wind turbine generates more power, as the wind speed increases as the distance from the ground increases. In this type of wind turbines there are fewer rotating and other mechanical elements, so the minimum operating life is 20-25 years. Vertical wind turbines are designed for the operating wind speed of 1-25 m/sec. Usually they are not designed for hurricane winds and therefore they must be lowered when a hurricane is approaching. The biggest advantage of vertical wind generators is their low starting (usually from 1-2 m/sec, and some from 0.5 m/sec) and nominal (7-8 m/sec) wind speed. This makes them very effective for use in continental areas where the average wind speed is 3-5 m/sec. Another important advantage of vertical wind turbines over horizontal ones is that they can be easily installed on flat roofs of buildings. This makes it possible to place them on the roofs of industrial facilities and significantly save on energy bills for businesses.
One of the problems in choosing and comparing wind turbines is the lack of a single standard for measuring power output. Manufacturers themselves choose at what wind speed to indicate the output power. To understand which wind turbine is suitable for you and your area, you need to take statistical data on wind speed and its distribution as a percentage of the year. The choice of wind turbine generator should be taken seriously, to explore different models and their capacity, to make calculations whether you pay off such a purchase, because there is no system of luck as in the best online casinos roulette game.
Thus, it is safe to say that with the advent of modern vertical wind turbines, the use of wind energy has become possible and effective not only in coastal, mountain or steppe areas, but also in continental areas.