Hydroelectric power plant (HPP) is a set of complex hydraulic structures and equipment. Its purpose is to convert energy of water flow into electrical energy. Hydraulic turbine is the main engine for HEP. With its help, the energy of water moving under pressure is transformed into mechanical energy of rotation, which then, via the electric generator is converted into electrical energy.
The most important hydraulic structure – the dam. It is built across the river from shore to shore and overlaps the channel of the river, preventing the free flow of its waters. Blocked river, dam on one of its side holds water at a higher level than the other, creating a differential in the levels and thereby increasing its energy. Because the energy of falling water is much greater than the energy of calmly running water. The dam built to use water power and electricity generation, for the detention of flood water (irrigation fields), for water supply of large cities, improving the navigation of the rivers. Dams are deaf, under any circumstances, not passing water from the high level to the lower, and spillway allowing overflow of water through the dam crest.
The dam, which is part of the hydroelectric – water drain. In her body – water-holes, through which water from the upper level is reset to bottom. The falling water rotates the hydraulic turbine – the main engines of the hydropower plant generates electricity.
Height differential (as experts say – pressure) created by the dam is determined by the requirements of energy, because the energy generated by the hydropower plant depends not only on the amount passed by the dam water, but the height from which it is discharged.
The height of the dam determines the construction material from which its constructed. Dams are earth, stone, rock excavation, concrete and reinforced concrete.
Most common among medium and large dams and reinforced concrete. By design, they are divided into massive (gravitational), arch gravity and arch. Massive dams are opposed by the pressure force of its own weight of water. Arch dams are built curved because of this they transfer the load from the reservoir on the rocky shore. Arched gravity dams, resist loads and its own weight, and focusing on the shore.
The oldest dams were found in Jerusalem and of Java in Jordan. These earthen dam with stone lining was built back in the year 3200 BC.
Today, the highest dam in the world located on the territory of the former USSR: the height of the dam is the Inguri dam – is 271.5 meters, Toktogul HPP – 215 meters, the Sayano Shushenskaya dam is 245 meters. The world’s highest dam, Nurek HPP – 310 meters.
Sayano Shushenskaya dam is the most powerful in the world. It is rated to handle 18 million tons from reservoirs.
The tallest dam in Africa built in 1971 in Egypt the city of Aswan. This dam (Sadd El Ali) allowed to control the annual flood of the Nile. Due to the construction of the dam became possible to cultivate more land. But also I have any other problems. So, for example, changed the composition of the soil around the Nile Delta due to high salt content in water and climate change in the region.
Aswan is a city on the East Bank of the Nile. It is located 966 kilometers South of Cairo. The dam is 13 kilometers upstream, South of Aswan. Approximately six kilometers downstream is the old Aswan dam, which was completed in 1902. In those days it was the biggest dam in the world, and the Arabs called it al Sadd.
The height of the new Aswan dam was 111 meters, the length is 3.8 kilometres. At the base it equal to the width of 975 meters and tapers to the upper edge of 40 meters.
For the construction of the dam went the number of stones, sand, clay and concrete is that this material could be constructed seventeen pyramids of Cheops.
On top of the dam allowed the four-lane road. The channel on the Eastern side of the dam drives the turbines of hydroelectric power. The resulting huge water tank has received the name of Egyptian President Nasser. This is one of the largest artificial lakes in the world. It covers an area of 5244 sq. km and stretches for 510 kilometers to the South, through Nubia to Sudan.
The dam was designed in Germany and built with the help of the Soviet Union. Building it cost the lives of 451 man. Because of its construction lost housing 60,000 Nubians and the Sudanese people. They were forced to move to other places. Water artificial lake was swallowed by the numerous ancient monuments. Only the most important of them were saved by the unprecedented action of UNESCO. Thus, the rock temples of Abu Simbel near the border of Egypt and Sudan were cut and transferred to a safe place.
World’s most powerful hydroelectric power plant is located in South America. October 13, 1982 in Brazil completed construction of the Itaipu dam, which managed to curb the rough waters of the paraná river, or, as it is called, – the “Mother sea”. For the first time in the world so the mighty river was able to implement a unique hydraulic operation. At the bottom of the river dropped twelve huge gates, which are closed hydraulically. The whole operation took exactly eight minutes. Then within two weeks the water in the river rose, stopped a giant concrete wall to make our planned level of 100 meters. From this height began a discharge of water through the special channel, shortly after reaching the planned level of 60,000 cubic meters per hour.
Currently in Brazil, developed an ambitious plan of facilities on the river Parana and its tributaries a system of hydroelectric power plants. He has more than thirty projects, of which a part is still under preparation and some are already under construction. The plan will produce 25 million kWh of electricity, apart from the fact that Itaipu produces already. Generators of hydroelectric power unit the most powerful in the world, each of them produces 700000 kilowatt. The total capacity of hydroelectric power is estimated at 12.6 million kilowatts.
The Itaipu project was born before the oil crisis in 1973. The last only reinforced the intention of the Brazilian government to better harness the immense energy resources of the country. Operation of hydroelectric power leads the company “Itaipu Binacional”, created in 1973. She belongs to Brazil and Paraguay, the countries sharing the generated electricity. The name “Itaipu” means “the Singing stone” and poetically conveys the sound of water rolling through rocky rapids.
The cost of the power plant – eleven billion dollars. Its construction worked 28000 workers. Giant concrete dam, which is five times larger than the Aswan, installed twenty kilometers to the North of the city of Foz do iguaçu. Its length is almost 8 kilometers and a height of 196 meters, width – 400 meters. For the construction of this massive structure was needed to divert the river on a two-kilometer channel width of 150 meters, punched in the rocks. After the river took, it took a while for the drying of the river bed, so the dam was started only in 1979.
Blocking the flow of the river, the dam has formed an artificial lake with an area of 1340 square kilometers. Before flooding this area were taken away everything of any significant archaeological sites – only about three hundred. After the flooding in the reservoir area were re-adaptation of many species of animals that lived there before the flooding. Besides, on the banks of an artificial lake was planted 20 million trees.