Wind - Wind Power
What is wind? Can I apply his energy and count on his help if it is perhaps the most delicate and a little predictable natural phenomenon? As he emerges, which is aimed, whether it could be «trust»? Because of how constant its nature depends on the efficiency of any wind energy plant.
Under the rays of the sun warmed the Earth's surface is heated and air. The intensity of heating UEMOA mainly from the state and properties of the earth's surface For example, the air in a desert of hot sand gets 130 times more heat than from the sea surface at the same latitude. The heated air reduces its density - are changing the atmospheric pressure, temperature increases, it decreases with decreasing - on the contrary. The masses of air with high pressure moving to where the pressure is lower, there is no wind. At the latitude of the equator due to the strong heating of the Earth's surface form a stable area of low pressure. It attracts air masses from the north and south - the winds are constant priority areas - trade winds. Under the influence of the Earth's rotation, they deviate slightly, in the northern hemisphere right in the course of air masses in the South - to the left.
At a height of 5- 7 km winds blow the opposite direction - counter trade. To the north and south of the equator there is a fairly narrow zone of sustained calm. Approximately at the latitude of 30 degrees on either side of the equator are observed second zone of calm, where replenished and down the cold currents from the equator, passed at the height of several kilometers - counter trade. You receive high-pressure zone, there are generated by trade winds. From this same area, winds blow toward the poles, the so-called prevailing west. Compared with the trade winds are much more volatile. This is a band between 30 and 60 ° north and south has long, thin, and the glory of the sailors nicknamed roaring forties. District of Bermuda at latitude 30, located in the zone of calm, sometimes called the horse latitudes. It is a strange and a bit gloomy name survived from the time of sailing ships. Many ships of that time were transported from Europe to the West Indies horses. Getting in the zone of calm, the court rendered immobile sag sail, dwindling reserves of fresh water and food supplies. First of all, with the dying horse. Thrown overboard, their bodies have long hovered over the waves.
At the poles due to the strong cooling there are two high-pressure areas from which the equator blows of polar easterly winds.
Under the action of sunlight land heats and cools faster than water, which has resulted in different seasons on the coasts of seas and oceans are formed seasonal winds blowing to the shore or from shore - the monsoons.
So, it turns out, the winds - a phenomenon not as natural as it may seem at first glance. At their persistence can be expected, their energy can be used without the fear that one, or more precisely, it is not perfect moment they will disappear altogether.
On the globe there are huge spaces over which winds blow from the permanent preferential direction and approximately the same force. Our country is due to its geographical position in this regard is in favorable conditions. It has unlimited resources of wind energy. There are huge areas in Russia , where wind energy can be used with maximum efficiency. Apply. For example, the Arctic coast of the Kola Peninsula to Chukotka, north of approximately sixty-seventh parallel, and Kamchatka . Duration of the wind in these areas, approximately 300-320 days per year.
What obstacles stand in the way of widespread use of wind? They are mainly two: the volatility of its direction and strength and the need for energy storage, in case no wind or small its power. First of all, perhaps, we should consider wind power as one way to get more energy, would reduce the consumption of fossil fuels.
Naturally, the greatest wind potential is observed on the sea coasts, on hills and mountains. Nevertheless, there are many other areas with potential wind, sufficient for use in wind energy. As a source of energy, wind is less predictable in contrast to, for example, the Sun, but at certain times of the presence of wind is observed throughout the day. At wind resources affects the Earth's terrain and obstructions located at an altitude of 100 meters . Therefore, the wind is largely dependent on local conditions than the energy of the sun. In hilly terrain, for example, two sites may have similar solar potential, but it is quite possible that their wind potential will be different, primarily because of differences in topography and direction of wind flows. In connection with this plan of room for windmills to be carried out more carefully than the installation of the solar system. Wind energy is also subject to seasonal changes in the weather: a more effective operation of wind turbines in the winter and less - in the hot summer months (in the case of solar systems, the opposite situation). In the climatic conditions of Denmark photovoltaic system is effective for 18% in January and 100% in July. The effectiveness of wind turbines in July - 55%, and in January - 100%. The best option is to combine in one system of small wind turbines and solar system. Such hybrid systems provide higher performance power than a standalone wind or photovoltaic installations.
It is also important to remember that the amount of energy produced by wind, depends on the density of air from the area covered by wind-turbine blades during rotation, as well as the cube of wind velocity. We know from physics course, that the kinetic energy of the moving body (e.g., air) is proportional to its mass, so wind power depends on the density of air. Density depends on the number of molecules per unit volume. At normal atmospheric pressure and temperature 15oC air density is 1,225 kg/m3. Due to the fact that the winter air is denser, wind generator will produce more energy in winter than in summer, at the same wind speed. The territory, located high above sea level, for example, in the mountains, atmospheric pressure is less and, consequently, less air density.