Hydropower is a form of renewable energy generation. Hydropower is now mostly used for hydroelectric power generation, as well as one part of a pumped-storage hydroelectricity energy storage system. Hydropower produced about 4500 TWh of electricity in 2020, which was more than all other renewables combined and also more than nuclear power. Hydropower, often known as water power, is the generation of electricity or the power of equipment using falling or fast-running water. This is accomplished by transforming a water source's gravitational potential or kinetic energy into electrical energy. Hydropower is an alternative to fossil fuels since it does not emit carbon dioxide or other pollutants into the atmosphere and provides a generally consistent source of energy. This article will explain to you about the Hydro Power which will be helpful in preparing the Environment syllabus for the UPSC Civil Service exam.

What is Hydro Power?

• Hydropower is the use of water's natural force to generate electricity (kinetic energy).
• Hydroelectric systems capture the energy and convert it to power using a turbine and generator.
• Because the sun replenishes the water supply, hydropower is regarded as a renewable energy source.
• This implies that it is a limitless resource. It's also environmentally friendly because it doesn't produce greenhouse gases, which contribute significantly to pollution and global warming.
• Today, China is the world's greatest hydropower generator, followed by Canada, Brazil, and the United States.
• Hydropower is expected to be the world's dominating energy resource for many years to come due to its abundance.

How do Hydropower Plants Work?

• Three things are required to generate hydroelectricity: moving water, a turbine, and a generator.
• Hydropower plants use the kinetic energy of moving water to generate electricity.
• They are, in theory, factories that turn the energy of falling water into a flow of electrons, or electricity.
• In most cases, a dam is built across a river to raise the water level and provide the necessary fall to produce a driving force.
• The falling water is then directed to a lower-level turbine wheel.
• A turbine wheel attached to a generator is turned by the flowing water.
• A rotor is attached to the generator, which is rotated by the turbine. The rotor of the generator produces electricity as it rotates.
• The generated electricity is then stepped up in voltage and delivered across transmission lines via the hydroelectric power station transformers.
• After serving its purpose, the used water is diverted out of the power plant and into the river's main channel, continuing the power generation cycle.

Types of Hydropower Plant

Impoundment Hydropower Plant

• An impoundment facility is the most prevalent type of hydroelectric power plant.
• A dam is used to store river water in a reservoir at an impoundment plant, which is usually a big hydroelectric system.
• Water released from the reservoir spins a turbine, which then activates a generator, which generates power.
• The water might be released to satisfy fluctuating electrical needs, as well as other purposes including flood control, recreation, fish passage, and other environmental and water quality concerns.

Impoundment Hydro Power Plant

Diversion Hydropower Plant

• This type of hydroelectric plant is also known as a run-of-river plant.
• Diversion is the process of generating energy by diverting a large percentage (about 90%) of a river's flow into a pipeline or tunnel to drive turbines before returning the water to the river's main channel.
• Turbines are not installed in the river in this variant.

Pumped storage Hydropower Plant

• Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage utilized by electric power systems for load balancing.
• Water pumped from a lower elevation reservoir to a higher elevation is used to store energy in the form of gravitational potential energy.
• Pumps are often powered by low-cost surplus off-peak electric power.
• During times of high demand for electricity, the stored water is released through turbines to generate electricity.
• Despite the fact that the plant is a net consumer of energy due to pumping losses, the system boosts revenue by selling more electricity during peak demand periods, when electricity prices are greatest.
• If the upper lake receives sufficient rainfall or is fed by a river, the plant, like a regular hydroelectric plant, might be a net energy producer.

Small Hydro Power (SHP)

• Any hydropower project with an installed capacity of less than 25 MW is classified as small hydro power.
• It is mainly run-of-river, with only a minor dam or barrage, usually only a weir and little or no water storage.
• As a result, run-of-river installations have less of an impact on the local ecosystem than large-scale hydro projects.
• Small hydropower facilities can independently meet the energy needs of isolated rural communities.
• India and China are the largest players in the SHP sector, with the most projects installed.

Small Hydro Potential in India

• A total of 5,415 small hydro sites have been discovered, with a total capacity of 19,750 MW.
• River-based projects in Himalayan states and irrigation canals in other states offer enormous potential for Small Hydro Project development.
• According to the objectives of XIIth five-year plan, Small hydro projects are expected to add 2.1 GW of capacity in the 2011-17 timeframe.
• The Ministry of New and Renewable Energy is supporting both public and private sector development of Small Hydro Projects, with the goal of exploiting at least half of the current potential in the next ten years.

Installed Capacity of Hydropower in India

• India has the fifth-largest installed hydroelectric power capacity in the world.
• India's installed utility-scale hydroelectric capacity was 46,000 MW as of March 31, 2020, accounting for 12.3 percent of the country's total utility power production capacity.
• A total of 4,683 MW (1.3 percent of the total utility power generation capacity) of smaller hydroelectric power units have been installed.
• At a 60% load factor, India's hydroelectric power potential is estimated to be 148,700 MW.
• In the fiscal year 2019–20, India generated 156 TWh of hydroelectric electricity (excluding small hydro) with an average capacity factor of 38.71 percent.
• Darjeeling's and Shivanasamudram's hydroelectric power stations were built in 1898 and 1902, respectively.
• They were among the earliest in Asia, and India has been a major player in the development of hydroelectric power around the world.
• Bhutan also exports excess hydroelectric power to India.

Advantages of Hydropower Plants

• Year Around Availability of Water: Water is a renewable natural resource that is available at all times of the year.
• Its quality and quantity may be diminished as a result of seasonal changes or other man-made factors, but it can be regenerated over time. Anyone installing hydropower plants will make certain that water is readily available in the areas where the plants are being installed.
• Lower Operational and maintenance cost: The cost of operation and maintenance is lower than that of other power plants. Hydropower plants require a lot of infrastructures to build embankments. Therefore the money or financing required is also a lot at first, although it's not as much as other plants.
• Nil Fuel Cost: Hydropower facilities do not require fuel because they rely on the flow of water to create electricity. Plants do not use water to generate electricity in the same way that other plants use fuel.
• Multi-purpose Use: Hydropower facilities are utilized for a variety of reasons, including irrigation, flood control, recreational activities, and so on. As a result, hydropower plants indirectly contribute to the development of a nation's economy.
• Reduced Working Hours: The number of people required to monitor the plant's operation is reduced. This also lowers the cost of operating hydroelectric facilities, making them more cost-effective for a country.

Disadvantages of Hydropower Plants

• Higher Embankment Construction Cost: Hydropower necessitates a large initial capital investment, whereas other electricity-generating plants necessitate the construction of plants and the installation of devices that are less costly.
• Large Land Space Requirement: Because an embankment or dam is built over a river, a vast amount of land is necessary to build up the massive infrastructure.
• Need for Abundant Water: Water is required in hydropower facilities, but the quantity can be reduced owing to drought conditions or natural causes, and with less water, electricity generation might be disrupted.
• Impact on Aquatic Life: Embankment makes it more difficult for fish to reach their spawning grounds, which has a negative impact on other creatures that rely on fish for food. The neighboring habitat of rivers is limited as the flow of water ceases, and they are unable to reach the water.
• Necessitates Evacuation: A hydroelectric plant, wherever it is built, has a huge impact on the surrounding community and area since residents must evacuate to meet the plant's needs. When a dam collapses owing to high wind and heavy rainfall, it might harm a significant number of people living nearby.

Conclusion

Hydropower is by far the most common renewable energy source, and it is expected to grow in importance in the coming years. Hydropower dams are the future of large-scale electricity generation. Several countries have spent billions of dollars upgrading dams and using them to generate electricity. The global hydropower generating market is estimated to reach $317.8 billion by 2027, according to Allied Market Research, with a CAGR of 5.9% from 2020 to 2027. The market has grown due to an increase in electricity demand and a preference for renewable energy.

FAQs

MCQs

1. Which of the following is the main source of energy in hydro power generation?

A) Solar radiation
B) Wind movement
C) Water flow
D) Biomass

2. What is the main disadvantage of hydro power?

A) High initial investment
B) Environmental impacts like ecosystem disruption
C) High greenhouse gas emissions
D) Limited availability of water resources

3. What type of hydro power plant does not require a large reservoir?

A) Run-of-the-river plants
B) Pumped-storage plants
C) Reservoir-based plants
D) All of the above

4. Which of the following is an advantage of hydro power?

A) It produces high levels of greenhouse gas emissions
B) It is a renewable source of energy
C) It is not reliable for large-scale energy production
D) It leads to habitat destruction

5. Which of the following is a potential solution to mitigate the environmental impacts of hydro power plants?

A) Using chemical fertilizers
B) Building larger dams
C) Restoring and protecting coastal ecosystems
D) Increasing fossil fuel usage

GS Mains Questions and Model Answers

Q1: Evaluate the role of hydro power in addressing India's energy needs and its environmental implications.

Answer: Hydro power plays a significant role in meeting India's energy demands, providing a clean and renewable alternative to fossil fuels. India has large untapped hydro power potential, especially in the Himalayan region, which could significantly contribute to the country's energy mix. However, the environmental impacts of large-scale hydro power projects, such as habitat disruption, changes in water flow, and displacement of local communities, must be carefully considered. Sustainable development practices, such as small-scale hydro power plants and ecosystem restoration, can mitigate these impacts while still benefiting from hydro power.

Q2: Discuss the advantages and disadvantages of hydro power as a renewable energy source.

Answer: Hydro power is one of the most widely used renewable energy sources due to its ability to provide a reliable and consistent energy supply. It has the advantage of low greenhouse gas emissions, making it environmentally friendly compared to fossil fuels. Hydro power can also be used to store energy in pumped-storage plants, helping to balance supply and demand. However, the disadvantages include significant environmental impacts, such as ecosystem disruption and the displacement of communities. The construction of large dams and reservoirs can also lead to biodiversity loss and changes in water quality.

Q3: How can technological advancements reduce the environmental impacts of hydro power?

Answer: Technological advancements in hydro power, such as improved turbine designs, fish-friendly turbines, and more efficient grid integration, can help reduce the environmental impacts of large-scale hydro power projects. Additionally, the use of small-scale and run-of-the-river plants, which have a smaller ecological footprint, can help mitigate environmental concerns. Incorporating environmental assessments and adaptive management strategies during the planning stages of hydro projects can also minimize adverse effects on local ecosystems and communities.

Previous Year Questions on Hydro Power

1. UPSC CSE Prelims 2020:

Question: Which of the following is the main advantage of hydro power?

A) It produces high amounts of CO2 emissions
B) It is non-renewable
C) It is a renewable and clean source of energy
D) It requires significant land use changes

Answer: (C)

Explanation: Hydro power is a renewable source of energy that harnesses the natural flow of water without producing greenhouse gases or air pollutants.

2. UPSC CSE Mains 2018 (GS Paper 3):

Question: "Analyze the environmental impacts of hydro power plants. What measures can be taken to reduce these impacts?"

Answer: The environmental impacts of hydro power plants include the disruption of ecosystems, fish migration, and the alteration of water quality and flow patterns. To reduce these impacts, careful planning and the use of fish-friendly turbines, along with the restoration of surrounding ecosystems, are essential. Small-scale hydro plants can also be promoted to reduce ecological disturbances.