Water is one of the most precious resources in nature. Water energy is one of the precious energies endowed by nature to human beings. The galloping rivers, towering dams, wide reservoirs, and dense power grids not only show the abundance of hydropower resources, but also the great achievements of human beings in the development and utilization of hydropower resources. Water energy is the only renewable conventional energy used in today's society. The water cycle on the earth provides the necessary material and energy guarantee for water energy. Thousands of endless rivers on the earth provide human beings with abundant water resources. The formation of river water energy has its basic conditions, mainly flow and drop. The greater the flow of the river and the greater the drop, the more abundant the hydropower resources.
China's "Eleventh Five-Year Plan for Energy Development" clearly stated in the energy base construction plan that hydropower bases should be actively developed. The development of hydropower resources does not produce "three industrial wastes" and other environmental impacts. Hydropower directly converts primary energy into secondary energy (electricity), utilizes the potential energy of water, and utilizes river flow and drop to obtain electricity. It is a completely physical process, in which neither consumes a A cubic meter of water does not pollute a cubic meter of water, does not emit a cubic meter of harmful gases, and does not emit a kilogram of solid waste. It is a clean energy source. As long as the water cycle on the earth does not stop and the rivers do not dry up, the water resources are eternal. is renewable.
Water energy resources, also known as hydraulic resources, are energy resources that exist in the water bodies of rivers, lakes and seas in the form of potential energy and kinetic energy. The meaning of hydropower resources can be divided into narrow sense hydropower resources and narrow sense hydropower resources.
In a narrow sense, water energy resources only refer to the energy resources such as kinetic energy, potential energy and pressure energy of water bodies, which are the output and energy of free-flowing natural rivers, which are called potential water energy resources of rivers, or hydraulic resources.
In a broad sense, water energy resources include river water energy, tidal water energy, wave energy, ocean current energy and other energy resources. Hydropower is a renewable energy source. By the early 1990s, river water energy was a large-scale use of water energy resources; tidal water energy had also been used successfully; wave energy and ocean current energy resources were being developed and researched.
Humans have a long history of using water energy, but in the early days, only water energy was converted into mechanical energy. It was not until the development of high-voltage power transmission technology and the invention of hydraulic alternators that water energy was developed and utilized on a large scale. At present, hydropower is almost the main way to utilize water energy, so hydropower is usually used as a synonym for water energy.
The most basic conditions for the formation of water energy resources are water flow and drop. The larger the flow, the larger the energy contained in the drop, that is, the larger the hidden water energy resources. The theoretical hydropower resources of the world's rivers are 48.2 trillion kWh/year, and the technically exploitable hydropower resources are 19.3 trillion kWh. The theoretical reserves of river hydropower in China are 691 million kilowatts, which can generate more than 6 trillion kilowatt-hours of electricity every year.
Hydropower is a clean and renewable energy source, but compared with the world's energy demand, hydropower resources are still very limited. Even if the world's hydropower resources are fully utilized, they will not be able to meet 10% of their demand at the end of the 20th century.
Humans have a long history of using water energy, but in the early days, only water energy was converted into mechanical energy. It was not until the development of high-voltage power transmission technology and the invention of hydraulic alternators that water energy was developed and utilized on a large scale. At present, hydropower is almost the main way to utilize water energy, so hydropower is usually used as a synonym for water energy.
The most basic conditions for the formation of water energy resources are water flow and drop. The larger the flow, the larger the energy contained in the drop, that is, the larger the hidden water energy resources. The theoretical hydropower resources of the world's rivers are 48.2 trillion kWh/year, and the technically exploitable hydropower resources are 19.3 trillion kWh. The theoretical reserves of river hydropower in China are 691 million kilowatts, which can generate more than 6 trillion kilowatt-hours of electricity every year.
Hydropower is a clean and renewable energy source, but compared with the world's energy demand, hydropower resources are still very limited. Even if the world's hydropower resources are fully utilized, they will not be able to meet 10% of their demand at the end of the 20th century.
Characteristics of hydropower and advantages and disadvantages of its development and utilization
The most notable feature of hydropower resources is that it is renewable and non-polluting. The development of water energy has a positive effect on the comprehensive management and comprehensive utilization of rivers, and is of great significance to promoting the development of the national economy, improving the energy consumption structure, and alleviating the environmental pollution caused by the consumption of coal and oil resources. can be placed at the top of the energy development strategy.
The biggest advantage of developing hydropower is low cost, continuous regeneration, and no pollution.
1. Hydropower is a renewable energy source that can be recycled year after year, while coal. Oil and natural gas are both consumable energy sources, which are exploited year by year, and the remaining ones are less and less, or even completely depleted.
2. Hydropower uses free fuel, low power generation cost, high accumulation, and quick investment recovery. Generally, large and medium-sized hydropower stations can recover all investment in 3-5 years.
3. Water energy has no pollution and is a clean green energy.
4. Hydropower stations generally have comprehensive economic benefits such as flood control and irrigation, shipping, breeding, beautifying the environment, and tourism.
5. Hydropower investment is similar to thermal power investment, and the construction period is not long, which is a short-term and instant benefit project.
6. There are few operation and management personnel, generally less than one third of thermal power personnel is enough.
7. Low operating cost and high efficiency
8. Power on demand
9. Can effectively control flooding;
10. Can provide irrigation water
11. Can improve river navigation
12. The relevant projects can simultaneously improve the transportation, power supply and economic development of the region, especially the development of tourism and aquaculture. The comprehensive development plan of the Tennessee River in the United States is the first large-scale water conservancy project, driving the overall economic development of the region.
The development of water energy has many advantages, but it also has its disadvantages: the distribution of water energy is greatly restricted by natural conditions such as hydrology, climate and landform. Water is easily polluted and easily affected by various factors such as terrain and climate.
1) Ecological damage, intensified erosion of water flow below the dam, changes in rivers and impacts on animals and plants, etc.;
2) The construction of a hydropower station requires dam construction and resettlement, etc. The infrastructure investment is large and the relocation task is arduous;
3) In areas where the precipitation season changes greatly, the power generation is low or even must be stopped in the rainy season;
4) The fertile land downstream of the hydropower station is impacted, and its accumulation gradually decreases.
If you want to know more about what hydropower is, you can read our other details on What is hydropower? Reading this article will deepen your understanding of it.