Advantages and disadvantages of hydropower, including its impact on the environment

Rivers flow for thousands of miles, containing huge energy. The development and utilization of natural water energy into electricity is called hydropower. The two basic elements that constitute hydraulic energy are flow and head. The flow is determined by the river itself, and the kinetic energy utilization rate of directly using the river water will be very low, because it is impossible to fill the entire section of the river with water turbines.
Hydraulic utilization mainly utilizes potential energy, and there must be a drop in the use of potential energy. However, the natural fall of rivers generally gradually forms along the river flow, and within a relatively short distance, the natural fall of water flow is relatively low. Appropriate engineering measures need to be taken to artificially increase the drop, which is to concentrate the scattered natural fall to form a usable water head.

Advantages of hydropower
1. Regeneration of water energy
Water energy comes from natural river runoff, which is mainly formed by natural gas and water circulation. The circulation of water enables water energy to be recycled and reused, so water energy is called “renewable energy”. “Renewable energy” has a unique position in energy construction.
2. Water resources can be comprehensively utilized
Hydroelectric power uses only the energy in the water flow and does not consume water. Therefore, water resources can be comprehensively utilized, and in addition to power generation, they can simultaneously benefit from flood control, irrigation, shipping, water supply, aquaculture, tourism, and other aspects, and carry out multi-objective development.
3. Regulation of water energy
Electric energy cannot be stored, and production and consumption are completed simultaneously. Water energy can be stored in reservoirs, which are produced according to the requirements of the power system. The reservoirs act as energy storage warehouses for the power system. The regulation of reservoirs improves the ability of the power system to regulate loads, increasing the reliability and flexibility of power supply.
4. Reversibility of hydropower generation
A water turbine that directs water from a high place to a low place can generate electricity and convert water energy into electrical energy; In turn, the water bodies located at the lower levels are absorbed by electric pumps and sent to reservoirs at the higher levels for storage, converting electrical energy into water energy. Using the reversibility of hydropower generation to build pumped storage power stations has a unique role in improving the load regulation ability of the power system.
5. Flexibility of unit operation
Hydroelectric power generation units have simple equipment, flexible and reliable operation, and are very convenient to increase or decrease loads. They can be quickly started or stopped according to the needs of users, and are easy to achieve automation. They are most suitable for undertaking peak shaving and frequency modulation tasks of the power system, as well as serving as emergency standby, load adjustment, and other functions. They can increase the reliability of the power system, with outstanding dynamic benefits. Hydroelectric power stations are the main bearers of dynamic loads in the power system.
6. Low cost and high efficiency of hydropower production
Hydropower does not consume fuel, and does not require a large number of manpower and facilities invested in the exploitation and transportation of fuel. The equipment is simple, with fewer operators, less auxiliary power, long service life of equipment, and low operation and maintenance costs. Therefore, the production cost of electric energy of hydropower stations is low, only 1/5 to 1/8 of that of fossil-fuel power station. In addition, the energy utilization rate of hydropower stations is high, reaching more than 85%, while that of fossil-fuel power station is only about 40%.
7. It is conducive to improving the ecological environment
Hydroelectric power generation does not pollute the environment. The vast water surface area of the reservoir regulates the microclimate of the region and the temporal and spatial distribution of water flow, which is conducive to improving the ecological environment of the surrounding areas. For coal-fired power plants, every ton of raw coal needs to emit about 30kg of SO2, and more than 30kg of particulate dust is emitted. According to the statistics of 50 large and medium-sized coal-fired power plants nationwide, 90% of the power plants emit SO2 with a concentration of more than 860mg/m3, which is very serious pollution. In today’s world where more and more attention is being paid to environmental issues, accelerating the construction of hydropower and increasing the proportion of hydropower in China are of great significance for reducing environmental pollution.

6666

Disadvantages of hydropower
Large one-time investment – huge earthwork and concrete works for the construction of hydropower stations; Moreover, it will cause considerable flooding losses and require huge resettlement costs to be paid; The construction period is also longer than the construction of thermal power plants, affecting the turnover of construction funds. Even if some of the investment in water conservancy projects is shared by various beneficiary departments, the investment per kilowatt of hydropower is much higher than that of thermal power. However, in future operations, the savings in annual operating expenses will be offset year by year. The maximum allowable compensation period is related to the country’s development level and energy policy. If the compensation period is less than the allowable value, it is considered reasonable to increase the installed capacity of the hydropower station.
Risk of failure – Due to flooding, dams block a large amount of water, natural disasters, man-made damage, and construction quality, which can have catastrophic consequences for downstream areas and infrastructure. Such failures may affect the power supply, animals and plants, and may also cause significant losses and casualties.
Ecosystem damage – Large reservoirs cause extensive flooding upstream of dams, sometimes destroying lowlands, valley forests, and grasslands. At the same time, it will also affect the aquatic ecosystem around the plant. It has a significant impact on fish, waterfowl, and other animals.


Post time: Apr-03-2023

Send your message to us:

Write your message here and send it to us