Hydropower resources have a finite value, although they are considered renewable. They are national we alth, like oil, gas or other minerals, and need to be handled carefully and thoughtfully.
Water Power
Even in ancient times, people noticed that water falling from top to bottom can do certain work, such as turning a wheel. This property of falling water began to be used to set the wheels of the mill in motion. This is how the first water mills appeared, which have survived to this day almost in their original form. The water mill is the first hydroelectric power plant.
Manufactory production, which originated in the 17th century, also used water wheels, and in the 18th century, for example, there were already about three thousand such manufactories in Russia. It is known that the most powerful installations of such wheels were used at the Krenholm manufactory (Narova River). The water wheels were 9.5 meters in diameter and developed up to 500 horsepower.
Hydropower resources: definition, advantages and disadvantages
In the 19thcentury after the water wheels appeared hydraulic turbines, and after them - electric machines. This made it possible to convert the energy of falling water into electrical energy, and then transmit it over a certain distance. In Tsarist Russia, by 1913, there were about 50,000 units equipped with hydro turbines that generated electricity.
That part of the energy of rivers 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 hydroelectric power station (HPP). The device of the power plant necessarily includes a hydraulic turbine, which drives an electric generator in rotation. To obtain the flow of falling water, the construction of a power plant involves the construction of dams and reservoirs.
Benefits of using hydropower:
- The river's energy is renewable.
- No environmental pollution.
- It turns out cheap electricity.
- Climatic conditions near the reservoir are improving.
Disadvantages of using hydropower:
- Flooding some area of land to build a reservoir.
- Changing many ecosystems along the riverbed, decreasing fish populations, disturbing bird nesting sites, polluting rivers.
- Danger of building in mountainous area.
The concept of hydropower potential
To assess the hydropower resources of a river, country or the entire planet on the WorldEnergy 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, which represents potential hydropower resources.
- Technical potential is that part of the gross potential that can be technically used.
- Economic potential is that part of the technical potential, the use of which is economically feasible.
The theoretical power of some water current is determined by the formula
N (kW)=9, 81QH, where Q is the water flow rate (m3/sec); H is the height of the water fall (m).
The world's most powerful hydroelectric power plant
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, and the first hydroelectric unit was launched. This hydroelectric power plant was to become the central hydroelectric power plant in China.
The view of the dam of this station resembles the design of the Krasnoyarsk hydroelectric power 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 release 116,000 m3 of water per second, that is, from a height of about 200 m, more than 100 tons of water falls in one second.
The Yangtze River, on which the Three Gorges Hydroelectric Power Plant is built, is one of the mostpowerful rivers of the world. The construction of a hydroelectric power station on this river makes it possible to use the natural hydropower resources of the area. Starting in Tibet, at an altitude of 5600 m, the river acquires a 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.
HPP design
The Three Gorges Hydropower Plant has three powerhouses containing 32 hydroelectric units, each with a capacity of 700 MW, and two hydroelectric units with a capacity of 50 MW. The total capacity of the HPP is 22.5 GW.
As a result of the construction of the dam, a reservoir with a volume of 39 km was formed3. The construction of the dam entailed the resettlement of residents of two cities with a total population of 1.24 million people. In addition, 1,300 archeological objects were removed from the flood zone. 11.25 billion dollars were spent on all the preparations for the construction of the dam. The total cost of construction of the Three Gorges hydroelectric power plant is $22.5 billion.
The construction of this hydroelectric power station correctly provides for navigation, moreover, after the construction of the reservoir, the flow of cargo ships increased 5 times.
Passenger ships pass the ship lift, which allows ships weighing no more than 3,000 tons to pass. Two lines of five-stage locks were built for the passage of cargo ships. In this case, the weight of the vessels must be less than 10,000 tons.
Yangtze HPP Cascade
The water and hydropower resources of the Yangtze River make it possible to build on thisthe river has more than one hydroelectric power station, which was undertaken in China. Above the Three Gorges hydroelectric power station, a whole cascade of hydroelectric power stations was built. This is the most powerful cascade of hydroelectric power plants with a capacity of over 80 GW.
The construction of the cascade avoids clogging of the Three Gorges reservoir, as it reduces erosion in the riverbed upstream of the hydroelectric power station. After that, there is less sludge to carry in the water.
In addition, the HPP cascade allows you to regulate the flow of water to the Three Gorges HPP and obtain uniform electricity generation at it.
Itaipu on the Parana River
Paraná 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 ground, therefore, overcoming it, it creates rapids and waterfalls on its way. This circumstance indicates favorable conditions for the construction of hydroelectric power plants here.
The Itaipu HPP was built on the Parana River, 20 km from the city of Foz do Iguacu in South America. In terms of power, this hydroelectric power plant is second only to the Three Gorges HPP. Located on the border of Brazil and Paraguay, the Itaipu HPP provides full electricity to Paraguay and 20% to Brazil.
The construction of the hydroelectric power plant began in 1970 and ended in 2007. Ten 700 MW generators have been installed on the Paraguay side and the same number on the Brazilian side. Since there was a tropical forest around the hydroelectric power station, which was subject to flooding, the 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. HPP capacity is 14,000 GW.
Russian hydropower resources
The Russian Federation has a large water and energy potential, but the country's hydropower resources are distributed extremely 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 by 46%, and the entire hydropower potential of the state is estimated at 2500 billion kWh. This is the second result in the world after China.
Sources of hydropower in Siberia
Siberia has huge reserves of hydropower, Eastern Siberia is especially rich in hydropower resources. The rivers Lena, Angara, Yenisei, Ob and Irtysh flow there. The hydro potential of this region is estimated at 1,000 billion kWh.
Sayano-Shushenskaya HPP named after P. S. Neporozhny
The capacity of this hydroelectric power plant is 6400 MW. This is the most powerful hydroelectric power plant in the Russian Federation, and it ranks 14th in the world ranking.
The section of the Yenisei, which is called the Sayan corridor, is favorable for the construction of hydroelectric power plants. Here the river passes through the Sayan Mountains, forming many rapids. It was in this place that the Sayano-Shushenskaya HPP was built, as well as other HPPs that form a cascade. The Sayano-Shushenskaya HPP is the highest step in this cascade.
Construction was carried out from 1963 to 2000. Station designconsists of a dam with a height of 245 meters and a length of 1075 meters, a power plant building, a switchgear and a spillway structure. There are 10 hydraulic units with a capacity of 640 MW each in the HPP building.
The reservoir formed after the construction of the dam has a volume of more than 30 km3, and its total area is 621 km2.
Large HPPs of the Russian Federation
The hydropower resources of Siberia are currently used by 20%, although many fairly large hydroelectric power stations have been built here. The largest among them is the Sayano-Shushenskaya HPP, followed by the following hydroelectric power plants:
- Krasnoyarskaya HPP with a capacity of 6000 MW (on the Yenisei). It has a ship lift, the only one in the Russian Federation so far.
- Bratskaya HPP with a capacity of 4500 MW (at the Angara).
- Ust-Ilimskaya HPP with a capacity of 3840 MW (at the Angara).
The Far East has the least developed potential. According to experts, the hydro potential of this region is used by 4%.
Sources of hydropower in Western Europe
In Western European countries, the hydropower potential is almost completely used. If it is also quite high, then such countries fully provide themselves with electricity from hydroelectric power plants. These are countries such as Norway, Austria and Switzerland. Norway ranks first in the world in the production of electricity per inhabitant of the country. In Norway, this figure is 24,000 kWh per year, and 99.6% of this energy is produced by hydroelectric power plants.
Hydropower potentialsdifferent countries of Western Europe differ markedly from each other. This is due to different terrain conditions and different runoff formation. 80% of Europe's total hydropower potential is concentrated in mountains with high flow rates: 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 are developed very significantly. For example, in Switzerland these resources are developed by 91%, in France - by 92%, in Italy - by 86%, and in Germany - by 76%.
HPP Cascade on the Rhine River
A cascade of hydroelectric power plants has been built on this river, consisting of 27 hydroelectric power plants with a total capacity of about 3,000 MW.
One of the stations was built in 1914. This is HPP Laufenburg. It underwent reconstruction twice, after which its capacity is 106 MW. In addition, the station belongs to the architectural monuments and is a national treasure of Switzerland.
HPP Rheinfelden is a modern hydroelectric power plant. 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 power station was built to replace the old station built in 1898. The old station is currently under renovation.
Sources of hydropower in Africa
Africa's hydropower resources are due to the rivers flowing through its territory: the Congo, the Nile, the Limpopo, the Niger and the Zambezi.
Congo Riverhas significant hydroelectric potential. Part of the course of this river has a cascade of waterfalls known as the Inga Rapids. Here, the water stream descends from a height of 100 meters at a speed of 26,000 m3 per second. In this area, 2 hydroelectric power plants were built: "Inga-1" and "Inga-2".
The Government of the Democratic Republic of the Congo in 2002 approved the project for the construction of 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. After the implementation of these plans, it was decided to build the largest Bolshaya Inga complex in the world.
This project was the topic of discussion at the International Energy Conference. Taking into account the state of Africa's water and hydropower resources, representatives of business and governments from Central and South Africa, who were present at the conference, approved this project and set its parameters: the capacity of the "Big Inga" was set at 40,000 MW, which is more than the most powerful hydroelectric power station " Three Gorges "almost 2 times. Commissioning of the HPP is scheduled for 2020, and construction costs are expected to be $80 billion.
Once the project is completed, the DRC will become the largest electricity supplier in the world.
North African power grid
North Africa is located along the coast of the Mediterranean Sea and the Atlantic Ocean. This region of Africa is called the Maghreb, or the Arab West.
Hydropower 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 providing these regions with water is a major task. Its solution is to build reservoirs.
The first reservoirs appeared in the Maghreb back in the 30s of the last century, then a lot of them were built in the 60s, but especially intensive construction began in the 21st century.
The hydropower resources of North Africa are determined mainly by the Nile River flowing here. This 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, about 500 km long and about 9 km wide. The filling of the reservoir with water took place over 5 years from 1970 to 1975.
The Aswan Dam was built by Egypt in cooperation with the Soviet Union. This was an international project, as a result of which it is possible to generate up to 10 billion kWh of electricity per year, control the water level in the Nile River during floods, and accumulate water in the reservoir for a long time. A network of canals irrigating fields diverges from the reservoir, and oases appeared on the site of the desert, more and more areas are used for agriculture. The water and hydropower resources of North Africa are used with maximum efficiency.
Sharing the world's hydropower potential
- Asia - 42%.
- Africa - 21%.
- North America - 12%.
- South America - 13%.
- Europe - 9%.
- Australia and Oceania – 3%
Global hydropower potential estimated at 10 trillion kWh of electricity.
The 20th century can be called the century of hydropower. The 21st century brings its own additions to the history of this industry. The world has increased attention to pumped storage power plants (PSPPs) and tidal power plants (TPPs), which use the power of sea tides to generate electrical energy. Hydropower development continues.
