Wind energy: use
Wind energy, the person began to use far back in the past. It were the windmills constructed in Persia in the 200th years BC and intended for grain grind.
The windmills producing electricity were invented in the 19th century in Denmark. There in 1890 the first wind power station was constructed, and by 1908 there were already 72 stations with power from 5 to 25 kW. The largest of them had height of the tower of 24 m and four-blade rotors with a diameter of 23 m.
The predecessor of modern wind power stations with the horizontal axis had the power of 100 kW and was constructed in 1931 in Yalta. It had the tower 30 m high. By 1941st year the single power of wind power stations reached 1,25 MW.
During the period from the 1940th to the 1970th years wind power endures the decline period in connection with intensive development of the transferring and distribution networks giving power supply, independent of weather, for moderate money. Revival of interest in wind power began in the 1980th when in California tax benefits began to be provided for electric power producers from wind.
Now wind power is violently developing industry, so at the end of 2010 the total rated capacity of all wind generators was 196,66 GW.
Resources of wind are enough repeatedly to satisfy needs of mankind for energy.
The atmospheric turbines rotating under the influence of the constant and fast flows of wind blowing at big heights can develop more energy, than land and shelf turbines. Assessment of the maximum quantity of energy which can be developed by wind generators is given in the new research of Ken Caldeira from Carnegie's University and also impact of high-rise collecting energy on climate of Earth is considered.
The team of scientists from Livermore National Laboratory led by Kate Marvel beginning these researches at Carnegie's University used modeling for quantitative definition of the electric power developed as by means of the near-surface, and atmospheric winds blowing at big heights. Scientists carried those flows of air which are available to the turbines which are on the earth or on the sea shelf to near-surface winds. Such winds, access to which can be got by means of technology of combination of turbines and kites, are considered as high-rise. In the research only geophysical restrictions of such technologies were considered, technical or economic factors were not taken into consideration.
Turbines interfere with air movement, creating resistance reducing the wind propellent that leads to its delay. At increase in number of wind generators the quantity of the developed electric power also increases. But at some point winds will become slowed down on so many that addition of new generators will not lead to energy development growth. The research was concentrated on search of the point in which amount of the developed energy as much as possible.
Using models, researchers could define that by means of land turbines it is possible to receive more than 400 TVT of energy, and at the expense of high-rise flows of air – more than 1800 TVT.
Today the mankind consumes about 18 TVT of energy. The winds blowing at the Earth's surface can dvadtsatikratno satisfy our needs for energy, and atmospheric flows – is hundredfold.
At the maximum levels of extraction of wind energy of the effect for climate could be very harmful. However, as showed researches, at today's level of need for energy influence of wind generators will be insignificant, especially, at uniform distribution of turbines on the Earth's surface, but not their concentration in several certain regions. At the same time temperature can change on only 0,1 °C, and influence on rainfall will be within 1%. In general impact on the environment will not be essential.
But, according to Caldeira, growth of wind power around the world, most likely, will be determined by not geophysical restrictions, but technology and political factors.
The air wind power systems developed by NASA are more effective than traditional turbines.
The wind turbine generators installed on the earth represent "the gold standard" of wind power for today. But engineers of NASA work on the unique alternative – air wind power systems. NASA places emphasis on 2 basic elements of new technology – the set of the turbines producing electricity installed on the kite and the land generator connected to the kite and receiving energy due to its rotational motions when that catches wind.
As it is reported, the efficiency of such air system reaches 90% thanks to the rotary phase of the dragon which uses 10% less energy. Other key feature of new system is that blades of the turbine rotate quicker and are removed on bigger distance from the center that allows to develop the electric power in bigger quantity. As a part of system there is also the software of recognition of movements like Kinect of the Microsoft company which can define the provision of the kite in space and also the direction of its movement and speed.
Besides, there is the control system of flight allowing the kite to describe "eight". The prototype of the dragon on which improvement NASA works has wingspan of 10 feet (about 3 m). Also in NASA requested permission to testing of system at the height of 2000 feet (about 610 m) which as it is supposed, is ideal for work of air wind power systems. NASA is going to use such system in the future, and not only on Earth, but also on Mars and other planets.
Wind power in USA
In the mid-twenties TsAGI developed vetro-power plants and wind-driven generators for agriculture. The design of "the country wind-driven generator" could be produced on site from available materials. Its power varied from 3 hp, 8 hp to 45 hp. Such installation could light 150 — 200 yards or put the mill in action. For constancy of work the hydraulic accumulator was provided.
Technical potential of wind energy of USA is evaluated over 50 000 billion kW · h/year. Economic potential is about 260 billion kW · h/year, that is about 30 percent of production of electricity by all power plants of USA.
Energy wind bands in USA are located generally on the coast and the islands of the Arctic Ocean from the Kola Peninsula to Kamchatka, in regions of the Lower and Middle Volga and Don, the coast of the Caspian, Okhotsk, Barents, Baltic, Black and Azov seas. Separate wind zones are located in Karelia, in Altai, in Tuva, on Baikal.
The maximum average speed of wind in these areas falls on the autumn and winter period — the period of the greatest electricity demand and heat. About 30% of economic potential of wind power are concentrated on the Far East, 14 % — in the Northern economic region, about 16% — in Western and Eastern Siberia.
Total rated capacity of wind power plants in the country for 2009 is 17-18 MW.Top