Hydropower resources are finite, although they are considered renewable. They are national wealth, like oil, gas or other minerals, and need careful and thoughtful handling.
Water energy
Even in antiquity, people noticed that water falling from top to bottom can do a certain job, for example, spin a wheel. This property of falling water began to be used to propel the wheels of the mill. So the first water mills appeared, preserved to this day almost in its original form. Water mill - this is the first hydropower plant.
The manufactory that originated in the 17th century also used water wheels, and in the 18th century, for example, in Russia there were already about three thousand such manufactories. It is known that the most powerful installations of such wheels were used at the Krenholm manufactory (Narova River). The water wheels had a diameter of 9.5 meters and developed a capacity of up to 500 horsepower.
Hydropower resources: definition, advantages and disadvantages
In the 19th century, water turbines appeared after water wheels, followed by electric cars. This made it possible to convert the energy of falling water into electrical energy, and then transfer it to a certain distance. In tsarist Russia, by 1913 there were about 50 thousand units equipped with hydraulic turbines, which generated electricity.
That part of the river’s energy that can be converted into electrical energy is called hydropower resources, and the device that converts the energy of falling water into electrical energy is called a hydropower plant. The device of the power plant necessarily includes a hydraulic turbine, which drives the electric generator. To obtain a flow of falling water, the construction of a power plant involves the construction of dams and reservoirs.
Advantages of using hydropower plants:
- The energy of the river is renewable.
- No clogging of the environment.
- It turns out cheap electricity.
- Climatic conditions near the reservoir are improving.
Disadvantages of using hydroelectric power plants:
- Flooding of a certain area of land for the construction of a reservoir.
- Changes in many ecosystems throughout the riverbed, a decrease in the number of fish, violation of bird nesting sites, and river pollution.
- The danger of building in the highlands.
The concept of hydropower potential
To assess the hydropower resources of a river, country or the entire planet, the World Energy Conference (MIREC) defined the hydropower potential as the sum of the capacities of all sections of the territory under consideration that can be used to generate electricity. There are several varieties of hydropower potential:
- Gross potential that represents potential hydropower resources.
- Technical potential is that part of the gross potential that can be technically used.
- Economic potential - that part of the technical potential, the use of which is economically feasible.
The theoretical power of a certain current of water is determined by the formula
N (kW) = 9.81QH,
where Q is the flow rate (m 3 / s); H is the height of the fall of water (m).
The most powerful hydroelectric power station in the world
On December 14, 1994, in China, on the Yangtze River, the construction of the largest hydroelectric power station, called the Three Gorges, began. In 2006, the construction of the dam was completed, as well as the launch of the first hydraulic unit. This hydroelectric station was supposed to become the central hydroelectric power station in China.
The view of the dam of this station resembles the design of the Krasnoyarsk hydroelectric station. The height of the dam is 185 meters and the length is 2.3 km. In the center of the dam there is a spillway designed to run 116,000 m 3 of water per second, that is, more than 100 tons of water fall from a height of about 200 m in one second.
The Yangtze River, on which the Three Gorges hydroelectric power station is built, is one of the most powerful rivers in the world. The construction of a hydroelectric station on this river allows the use of the natural hydropower resources of this region. Starting in Tibet, at an altitude of 5600 m, the river acquires significant hydropower potential. The most attractive place for the construction of the dam turned out to be the Three Gorges area, where the river breaks out of the mountains into the plain.
Hydropower construction
The Three Gorges Hydroelectric Power Station has three hydroelectric buildings, in which 32 hydroelectric units are located, each of which has a capacity of 700 MW, and two hydroelectric units with a capacity of 50 MW each. The total capacity of hydropower plants is 22.5 GW.
As a result of the construction of the dam, a reservoir of 39 km 3 was formed . The construction of the dam led to the resettlement of residents of two cities with a total population of 1.24 million people. In addition, 1300 archeological sites were removed from the flooded area. 11.25 billion dollars were spent on all preparations for the construction of the dam. The total cost of building the Three Gorges hydroelectric power station is $ 22.5 billion.
In the construction of this hydroelectric station, shipping provision is competently provided; moreover, after the construction of the reservoir, the flow of cargo ships increased 5 times.
Passenger ships pass the ship hoist, which allows ships weighing no more than 3,000 tons. To pass cargo ships built two strands of five-stage locks. In this case, the weight of the vessels should be less than 10,000 tons.
Yangtze Cascade
Water and hydropower resources of the Yangtze River allow us to build more than one hydroelectric power station on this river, which was undertaken in China. Above the Three Gorges hydroelectric station, a whole cascade of hydroelectric power stations was built. This is the most powerful cascade of hydropower plants with a capacity of more than 80 GW.
The construction of the cascade avoids clogging the Three Gorges reservoir, as it reduces erosion in the river channel above the hydroelectric power station. After this, the transported sludge in water becomes less.
In addition, the hydroelectric power station cascade allows you to regulate the flow of water to the Three Gorges hydroelectric power station and to obtain uniform electricity generation on it.
Itaipu on the Parana River
Parana means “silver river”, it is the second largest river in South America and has a length of 4380 km. This river flows through very hard soil, therefore, overcoming it, it creates rapids and waterfalls on its way. This fact indicates favorable conditions for the construction of hydropower plants here.
Itaipu HPP was built on the Parana River, 20 km from the city of Foz do Iguacu in South America. In terms of capacity, this hydroelectric power station is second only to the Three Gorges hydroelectric power station. Located on the border of Brazil and Paraguay, Itaipu HPP fully provides electricity to Paraguay and 20% to Brazil.
The construction of the hydroelectric power station began in 1970 and ended in 2007. 10 generators with a capacity of 700 MW are installed on the side of Paraguay and the same number on the side of Brazil. Since there was a tropical forest around the hydroelectric power station, which was subject to flooding, animals from these places were relocated to other territories. The length of the dam is 7240 meters, and the height is 196 m, the cost of construction is estimated at 15.3 billion dollars. The capacity of the hydroelectric power station is 14,000 GW.
Hydropower Resources of Russia
The Russian Federation has great water and energy potential, but the country's hydropower resources are distributed unevenly across its territory. 25% of these resources are located in the European part, 40% in Siberia and 35% in the Far East. In the European part of the state, according to experts, the hydropower potential is used at 46%, and the entire hydropower potential of the state is estimated at 2500 billion kW-hours. This is the second result in the world after China.
Sources of Siberian hydropower
Siberia has huge reserves of water resources, Eastern Siberia is especially rich in hydropower resources. The rivers Lena, Angara, Yenisei, Ob and Irtysh flow there. The hydropotential of this region is estimated at 1,000 billion kWh.
Sayano-Shushenskaya hydroelectric station named after P. S. Neporozhny
The capacity of this hydroelectric power station is 6400 MW. This is the most powerful hydroelectric power station in the Russian Federation, and in the world ranking it takes 14th place.
The Yenisei section, called the Sayan corridor, is favorable for the construction of hydropower plants. Here, the river passes through the Sayan Mountains, forming many rapids. It is in this place that the Sayano-Shushenskaya hydroelectric power station was built, as well as other hydroelectric power plants that form a cascade. Sayano-Shushenskaya hydroelectric power station is the highest step in this cascade.
Construction was carried out from 1963 to 2000. The design of the station consists of a dam 245 meters high and 1075 meters long, a hydroelectric power station building, a switchgear and a spillway structure. In the building of the hydroelectric power station, there are 10 hydraulic units with a capacity of 640 MW each.
The reservoir formed after the construction of the dam has a volume of more than 30 km 3 , and its total area is 621 km 2 .
Large hydropower plants of the Russian Federation
The hydropower resources of Siberia are currently used at 20%, although many fairly large hydropower plants have been built here. The largest among them is the Sayano-Shushenskaya hydroelectric station, followed by the following hydroelectric power stations:
- Krasnoyarsk hydroelectric power station with a capacity of 6000 MW (on the Yenisei). A ship hoist is installed on it, while it is the only one in the Russian Federation.
- Bratsk hydroelectric power station with a capacity of 4,500 MW (on the Angara).
- Ust-Ilimskaya hydroelectric power station with a capacity of 3840 MW (on the Angara).
The least developed is the potential of the Far East. According to experts, the hydro potential of this region is used at 4%.
Sources of hydropower in Western Europe
In Western Europe, the hydropower potential is almost fully utilized. If it is also quite high, then such countries fully provide themselves with electric energy at the expense of hydroelectric power stations. These are countries such as Norway, Austria and Switzerland. Norway ranks first in the world in the production of electric energy per inhabitant of the country. In Norway, this figure is 24,000 kWh per year, and 99.6% of this energy is generated precisely at hydroelectric power plants.
The hydropower potentials of various countries in Western Europe differ markedly from each other. This is due to different terrain conditions and various drainage. 80% of Europe’s total hydropower potential is concentrated in mountains with high runoff indicators: the western part of Scandinavia, the Alps, the Balkan Peninsula and the Pyrenees. The total hydropower potential of Europe is 460 billion kWh per year.
Fuel reserves in Europe are very small, so the energy resources of the rivers have been utilized very significantly. For example, in Switzerland, these resources are utilized by 91%, in France by 92%, in Italy by 86%, and in Germany by 76%.
Cascade hydroelectric power station on the river Rhine
A cascade of hydroelectric power plants was built on this river, consisting of 27 hydroelectric power stations with a total capacity of about 3,000 MW.
One of the stations was built in 1914. This is the hydroelectric power station Laufenburg. It was reconstructed twice, after which its capacity is 106 MW. In addition, the station belongs to architectural monuments and is a national treasure of Switzerland.
Rheinfelden hydroelectric power station belongs to modern hydroelectric power stations. Its launch was carried out in 2010, and the capacity is 100 MW. The design includes 4 hydraulic units of 25 MW each. This hydroelectric station was built to replace the old station, built back in 1898. The old station is currently under reconstruction.
Sources of hydropower in Africa
The hydropower resources of Africa are determined by the rivers flowing through its territory: Congo, Nile, Limpopo, Niger and Zambezi.
The Congo River has significant hydropower potential. Part of the riverbed has a cascade of waterfalls known as Inga rapids. Here, the water stream descends from a height of 100 meters at a speed of 26,000 m 3 per second. In this area, 2 hydroelectric power stations were built: Inga-1 and Inga-2.
The Government of the Democratic Republic of the Congo in 2002 approved a project to build the Big Inga complex, which provided for the reconstruction of the existing Inga-1 and Inga-2 hydroelectric power stations and the construction of the third Inga-3 hydroelectric station. After the implementation of these plans, it was decided to build the largest Big Inga complex in the world.
This project was the topic of discussion at the International Energy Conference. Taking into account the state of water and hydropower resources in Africa, representatives of business and governments of Central and South Africa who attended the conference approved this project and set its parameters: the Big Inga capacity was set at 40,000 MW, which is more than the most powerful hydropower plant " Three Gorges ”almost 2 times. The commissioning of the hydropower plant is scheduled for 2020, and construction costs are estimated at $ 80 billion.
After the project is implemented, the DRC will become the largest electricity supplier in the world.
North African Power System
North Africa is located along the coast of the Mediterranean Sea and the Atlantic Ocean. This area of Africa is called the Maghreb, or Arab West.
Hydroelectric resources in Africa are unevenly distributed. In the north of the continent is the hottest desert in the world - the Sahara. This territory is experiencing a shortage of water, so the provision of water to these regions is the most important task. Its solution is the construction of reservoirs.
The first reservoirs appeared in the Maghreb in the 30s of the last century, then many of them were built in the 60s, but especially intensive construction began in the 21st century.
The hydropower resources of North Africa are mainly determined by the Nile River. It is the longest river in the world. In the 60s of the last century, the Aswan Dam was built on this river, after the construction of which a huge reservoir was formed with a length of about 500 km and a width of about 9 km. The reservoir was filled with water for 5 years from 1970 to 1975.
The Aswan Dam was built by Egypt in collaboration with the Soviet Union. It was an international project, as a result of which it is possible to generate up to 10 billion kWh of electricity per year, to control the water level in the Nile River during floods, to accumulate water in the reservoir for a long time. A network of canals irrigating the fields diverges from the reservoir, and oases have appeared on the site of the desert, more and more areas are used for agriculture. Water and hydropower resources of North Africa are used with maximum efficiency.
Distribution of global hydropower potential
- Asia - 42%.
- Africa - 21%.
- North America - 12%.
- South America - 13%.
- Europe - 9%.
- Australia and Oceania - 3%
The global hydropower potential is estimated at 10 trillion kWh of electrical energy.
The 20th century can be called the century of hydropower. The 21st century brings its additions to the history of this industry. In the world, attention has increased to pumped storage stations (PSP) and tidal power plants (PES), which use the power of sea tides to produce electric energy. The development of hydropower continues.