Siemens SWT-7.0-154

Who said that windmills are not able to compete in power with nuclear power plants? Look at the world's largest wind turbine Siemens SWT-7.0-154. With an area of ​​18,600 m², this giant alone generates a maximum power of 7 MW at a wind speed of 13-15 m / s. Several hundred of such windmills - and here you have an atomic power station.



SWT-7.0-154 is Siemens' flagship model. In its name, the generated power (7 MW) and the diameter of the rotor with blades (154 m) are encrypted. It replaced the previous flagship SWT-6.0-154, from which it practically does not differ in technical specifications, but is equipped with more powerful magnets. A stronger magnetic field allows you to generate more electricity with the same diameter. In other words, in this VEN, the parameter of the power removed from a square meter of the area of ​​measurement is approximately 16.7% higher.
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The wind generator starts up at a minimum wind speed of 3-5 m / s, and the generated power increases progressively to a maximum of 7 MW at a wind speed of 13-15 m / s. When the wind speed reaches 25 m / s, the generation stops.

It would seem that at such wind speeds, wind turbine blades should rotate rapidly, but this is absolutely not the case. In fact, they rotate slowly and sedately, making only 5-11 revolutions per minute. That is, a full turn of the three blades make about 5-12 seconds, depending on the wind speed.

A stronger magnetic field in the new model also means that this turbine is harder to spin. To achieve the same rotational speed of 5-11 revolutions per minute and the maximum generated power (7 MW instead of 6 MW), this turbine requires increased wind speed: 13-15 m / s instead of 12-14 m / s. Accordingly, the initial speed of wind generation is higher. That is why this giant model is best suited for placement in areas with relatively strong winds, best in the sea.

Inside the turbine there is no gearbox (gearbox) - there works a direct drive system connected to a synchronous alternator with permanent magnets. Since the speed of the generator determines the voltage and frequency of the current, the “dirty alternating current” is converted to direct current and then converted back to alternating current before being fed into the network.

In recent years, very rapid scientific and technical progress has been occurring in the field of wind energy. Literally every year there are new models of wind turbines of greater power and efficiency. Large and small, designed for entire villages or individual houses, for high wind speeds in the sea or for average wind speed over the roof of a private house.

For example, the world record for the maximum generated power does not belong to Siemens, but to another turbine of another German manufacturer Enercon E126, which produces up to 7.58 MW. The video shows the installation process of such a turbine.


The height of the stand of the Enercon E126 is 135 m, the diameter of the rotor is 126 m, the total height with the blades is 198 m. The total weight of the turbine foundation is 2500 tons, and the wind generator itself is 2800 tons. Only the electric generator weighs 220 tons, and the rotor together with the blades - 364 tons. The total weight of the whole structure with all the details is 6000 tons. The first installation of this type was installed near the German Emden in 2007, although in that modification the maximum power was less.

However, giant wind turbines are quite expensive. One such 7 MW wind turbine will cost $ 14 million along with the installation, if you order all the work from certified German specialists. Of course, if you master the production in your country, the benefit of the metal is enough, then the cost may well be reduced several times. Who knows, maybe such a giant project of national construction would occupy the population of the country and help get out of the economic crisis.

Why windmills will not replace nuclear power plants

One of the most recent nuclear power plants under construction in Belarus - the Belarusian NPP - will receive two power units with VVER-1200 reactors with a capacity of 1200 MW each. It would seem that several hundred Siemens windmills compare with a nuclear power plant. The cost of construction is about the same, but the "fuel" is free. Interestingly, the Belarusian NPP is being built in an area where, according to climatic data for 1962-2000, almost the highest average annual wind speed is in Belarus. But in reality, this “biggest” average annual wind speed is only about 4 m / s (at a height of 10 m), which is barely enough to run a wind turbine at minimum power.

Before installation, it is necessary to check the annual map of the winds in the area of ​​dislocation with the data of the average specific power of the wind flow at an altitude of 100 m and above. It would be good to make such maps for the whole territory of the country in order to find the places for the most optimal construction of wind turbines. It should be borne in mind that the wind speed is highly dependent on the height, which is well known to residents of high-rise buildings. In normal weather forecasts, TV reports wind speeds at a height of 10 meters above the ground, and for a wind turbine, measure speeds at a height of 100-150 meters, where the winds are much stronger.

So the most optimal such giants are suitable for installation in the sea, a few kilometers from the coast, at high altitude. For example, if such installations are installed along the northern coast of Russia with a step of 200 meters, then the maximum capacity of the array will be 690.3 GW (the coast of the Arctic Ocean is 19,724.1 km). The wind speed there should be acceptable, only when pouring foundations will have to deal with permafrost.

True, the stability of the wind turbine never compare with a nuclear power plant or hydroelectric station. Here, power engineers have to constantly monitor the weather forecast, because the generated power is directly dependent on the wind speed. The wind should not be too strong and not too weak. It is good if, on average, wind turbines will produce at least one third of the maximum power.