Hydropower in Nepal- Most Sustainable Solution?
A dam or construction area that helps within the natural flow of water is used to generate power from a water source, often referred to as hydroelectric power or simply hydropower. So as to generate energy, hydropower uses the perpetual, never-ending water cycle, which uses water as a fuel and leaves no waste products behind. Although there are many various kinds of hydropower plants, they’re always propelled by the kinetic energy of water moving downstream. so as to turn this kinetic energy into electricity, which can subsequently be used to power buildings, businesses, and other establishments, hydropower uses turbines and generators.
Basic Terminology in Hydropower Sector
This section describes the basic terms and terminologies that are often used while talking about Hydro Electricity projects. Everyone must keep knowledge regarding these basic terms.
A dam is a massive wall or barrier across a flowing stream to hold water upstream in order to raise the water level to create a powerful fall. It is also used as a reservoir to hold back water and controls the flow of water.
A dam provides water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. A dam is also supposed to prevent a particular place from natural calamities such as floods and landslides, it also helps to protect natural habitats of flora and fauna.
A forebay is a human-made pool of water that looks very much like a reservoir provided in front of the penstock pipe. The water from a forebay is taken out to run the equipment such as waterwheels or turbines. The capacity of any forebay depends on the volume of water that deposits in the intake area. Forebays have a number of functions, some of which are listed below:
- Acts as a buffer zone during flooding and release in a controlled way.
- To trap sediment and debris, in order to keep large bodies of water cleaner and clearer.
- Some forebays are used simply to create a natural habitat for flora and fauna.
A penstock is an intake structure that controls water flow which consists of an enclosed pipe that delivers water to the hydraulic turbines. Penstocks are made up of strong structures like metal or concrete and are placed at 45 degrees (optimal efficiency). Penstock can be steel or concrete structures and may be single or multiple pipes depending on water volume. Penstocks for hydroelectric installations are normally equipped with a gate system and surge tank.
- Penstocks gates are fixed to the initial of penstocks and the flow of water is controlled by operating penstock gates
- A surge tank is a storage reservoir located near the beginning of the penstock to receive the rejected flow when the pipeline is suddenly closed by a valve fitted at its steep end. It is usually provided in high-head plants
A water turbine is a rotary engine that takes energy from moving water, it is much like a windmill, except the energy is provided by falling water instead of wind. The turbine converts the kinetic energy of falling water into mechanical energy. Flowing water is directed onto the blades of a turbine runner, creating a force on the blade. The turbines are classified into two classes based on the size of the head of the power plant.
Impulse Turbine (High Head Plants)
- Pelton wheel turbines
- Turgo turbines
- Michell-banki turbines (cross flow or ossberger turbine)
Reaction turbine (Low and Medium Head Plants)
- Francis turbine
- Kaplan turbine
A powerhouse is also known as a power station, generating station, or power plant. It is a point of hydropower generation from water or an industrial facility for the generation of electric energy. The amount of electricity generated in the powerhouse depends on the capacity of Forebay and the height difference between Forebay and the powerhouse (head difference). At the center of nearly all power stations is a generator,
A generator is a rotating machine that converts mechanical energy into electrical energy by creating relative motion between a magnetic field and a conductor. Converts the mechanical energy from the turbine into electric energy. Generators in hydropower plants work very much like generators in other types of power operations.
Potential Energy – Kinetic Energy – Mechanical Energy – Electrical Energy (Electricity)
A tailrace is a channel or part below the water wheel or a turbine through which the spent water flows without any disturbance. It is the downstream part where the water re-enters the river. It is usually the lowest point of the project.
8. Transmission lines
The transmission lines conduct electricity from the hydropower plant to homes and businesses.
How is Electricity Generated from Hydropower?
A sustainable energy source known as hydroelectricity uses the force of moving water to generate electricity. Long before you turn on the light at home or at work, the hydroelectric process has already begun. The majority of large-scale hydroelectricity projects use dams. Tidal and run-of-river projects also use the force of flowing water to produce sustainable electricity.
The potential energy that is held in a water reservoir behind a hydroelectric dam is transformed into mechanical energy, also referred to as kinetic energy. A turbine is turned by the water’s kinetic energy as it passes through the dam. The turbine’s mechanical energy is transformed into electricity by the generator. Then, before it reaches you, this electrical energy flows through a number of transmission procedures.
Hydropower in Nepal
There are over 6000 rivers in our country, with a total reach length of 45000 km. About 3.9% of Nepal’s entire land area is made up of them. The icy mountains and lakes formed by glaciers are also our main sources of water. The majority of Nepal’s hydroelectric projects are owned by the Nepal Electricity Authority (NEA) and numerous Independent Power Producers. In the coming years, a number of hydroelectric projects that are currently under construction will be completed. Run-of-river hydropower makes up the majority of Nepal’s current hydropower.
History of Hydropower in Nepal
The installation of 500 kW of electricity at Pharping, known as Chandra Jyoti, on May 22, 1911, marked the beginning of the development of hydropower in Nepal. It is the oldest hydropower in Nepal which was inaugurated by His Majesty King Prithivi Bir Bikram Shah Dev in 1911 AD. It uses 2 Pelton turbines and has a total capacity of 500 kW but is no longer in operation due to the supply of water to Kathmandu valley.
The Pharping hydropower served electricity to the Kathmandu Valley and the periphery for many years. After a huge gap of time, 2nd hydropower of Nepal, Sundarijal hydropower was established in 1936. And then a number of hydropower like Panauti, Trishuli, Dhankuta, and Sunkoshi were established in Nepal.
After 25 years, the 900 kW, 640 kW Sundarijal Hydropower Plant was started in 1936 by Prime Minister Dev Shamsher. For many years, Sundarijal, hydroelectric development in Nepal was constructed. Later, through public-private collaboration, the Morang Hydropower Company, founded in 1939, finished building the third Letang hydropower plant with an installed capacity of 1800 kW in AD 1943.
The plant, which provided Biratnagar Jute Mill with energy, was eventually destroyed by a landslide. The Koshi and Gandak Projects, created in 1954 and 1959 to meet Nepal’s irrigation needs and serve as a hydroelectric component, were historically the country’s first bilateral agreements with India.
Electricity demand increased from 557 MW in 2005 to 1200 MW in 2013, according to estimates. In 2013, there were 733 MW of hydropower available, including 255 MW operated by the commercial sector and 478 MW owned by NEA. Similarly, the expected demand for electricity was 105 GWh in 2006–2007 and increased to 678 GWh in 2009–2010, with a brief peak of 745 GWh in 2008–2009.
Therefore, all RoR hydropower units, with the exception of those with a capacity of 92 MW for storage, were the primary cause of the issue. From the current growing demand of 4430 GWh per year to the system peak load of 17,400 GWh with the yearly growth projection of 3679 MW by 2027, the predicted growth rate of the energy demand will be 8.34 percent.
The Upper Tamakoshi Hydropower, the Biggest hydropower plant in Nepal, is an esteemed turning point in the country’s energy transition. The factory is situated about six kilometers from the Tibet border in a remote area of the upper Himalayas in the Tamakoshi River basin. With six underground units and a natural head of 822 m, it may generate up to 2,281 GWh of energy yearly. The country’s economy will grow and living standards will be raised thanks to this renewable energy.
Status of Power Generation and Transmission
This table shows almost all the hydropower projects with their capacity and date of establishment, that are generating power and connected to the national grid to distribute electricity throughout the country.
|Kali Gandaki||144||2002||Indrawati III||7.5||2002|
|Middle Marsyangdi||70||2008||Puwa Khola||6.2||1999|
|Khimti I||60||2000||Panauti (Khopasi) Hydropower||2.4||1965|
|Upper Marsyangdi A||50||2016||Seti||1.5||1985|
|Upper Bhote Koshi||45||2001||Fewa Hydropower||1||1969|
|Kulekhani II||32||1986||Jhimruk Khola||12||1994|
|Trishuli||24 (initially 21, rehabilitated in 1995)||1967||Sunkoshi||10.05||1972|
|Chilime||22||2003||Lower Modi I||10||2012|
|Gandak||15||1979||Andhi Khola||9.4 (initially 5.1, rehabilitated in 2016)||1991|
|Modi Khola||14.8||2000||Madkyu Khola||13||2018|
Hydropower Plants under Construction in Nepal
Some hydropower projects with great potential are under construction in Nepal. The following table shows the list of hydropower under construction in our country with their potential and the expected date of completion.
|Hydropower Station||Capacity (MW)||Date of Completion||Hydropower Station||Capacity(MW)||Date of Completion|
|Arun III||900||2022||Upper Sanjen||14.8||–|
|Upper Tamakoshi Project||456||2019 (November)||Iwa Khola||9.9||–|
|Rasuwagadi||111||2020 (February)||Rudi Khola A||8.8||–|
|Middle Bhotekoshi||102||2019 (June)||Upper Naugad Gad||8||–|
|Lower Solu||82||–||Theule Khola||1.5||–|
|Trishuli 3A||60||–||Mistri Khola||42||–|
|Upper Marsyangdi A||50||–||Khani Khola (Dolakha)||30||–|
|Lower Sanjen||42.5||–||Khani Khola I||25||–|
|Kabeli B1||25||–||Kulekhani III||14||–|
|Lower Hewa Khola||21.6||—||Gamgadhi||0.4||–|
Upcoming Projects for Hydropower in Nepal
The government of Nepal has plans to construct a few projects under hydropower in Nepal that have the greatest potential till now. Some of the listed projects have already been mentioned in the ‘Nation Pride Projects.’
|Hydro-Power Station||Capacity (MW)||Hydro-Power Station||Capacity (MW)|
|Kali Gandaki II||660||Khimti II||27|
|Lower Arun||308||Upper Modi||14|
|Upper Arun||335||Langtang Khola||218|
|Upper Karnali||300||Upper Seti||122|
|Thulo Dhunga||25||Upper Tamakoshi||456|
|Tavur/Mewa||101||Upper Modi ‘A’||42|
|Budhiganga||20||Upper Trishuli ‘B’||37|
|Rahughat Khola||27||Karnali Phase I||1,080|
Issues in the Hydropower Sectors in Nepal
It has become very essential to identify the real potential of hydropower projects in Nepal. Government must identify the need to develop hydropower projects according to the planned program. Current plans and policies must be improved so that hydropower in Nepal gets support from internal financial resources. Despite the fact that a lot has happened in this sector, Hydropower in Nepal is hampered by numerous issues. Some are discussed below.
1. Absence of Policy Interventions
The goal of Nepal’s first comprehensive hydropower laws, which were released in the early 1990s, was to prevent deforestation and close the supply-demand gap. Other objectives included obtaining money from the private sector for infrastructure development and utilizing domestic resources for hydropower development. The slower rate of public sector hydropower development is a definite setback for planners who had hoped that an alluring hydropower policy would attract additional investment capital to Nepal.
2. Market failure in financial intermediaries (FIS)
Market failure appears to be significant due to the short-term nature of the deposit base (the debts supplied by the banks and their capital base are limited), and it will be a portfolio mismatch for them to make long-term loans. Therefore, FIS seems reluctant to help private entrepreneurs take the necessary share in hydropower development.
3. Topological Difficulty
India borders Nepal on three sides (the south, the east, and the west), and the Tibet Autonomous Region of China borders Nepal on the north. Between Nepal and Bangladesh is the tiny Siliguri corridor, also known as the chicken neck of West Bengal. Long transmission lines are needed due to the challenging terrain and dispersed settlements, and connecting to national or regional grids may cost two to five times as much as producing electricity in large, centralized plants.
4. Fragile Structure
The Himalayas are the world’s most dynamic and vulnerable mountain range, frequently referred to as a live mountain with active tectonics. The Himalayas are still rising and their rocks are constantly under pressure because the Indian plate, which is moving toward the north, is pushing against the more stable Tibetan block. The Himalayas is compelled by this pressure to rise and shift horizontally southward along large thrusts, which is frequently reflected in a high frequency of earthquakes. The Himalayas is also fundamentally vulnerable due to the rocks’ poor geological features.
The demand for electrical energy over all other forms of energy, as well as the total installed capacity for power generation in Nepal, are hot topics. The government’s top priority should be to focus all of its efforts in a single direction to provide power as customers desire in order to energize the whole economic sector. In addition, the hydropower industry in Nepal attracts a lot of private-sector developers and large-scale domestic and foreign investors in addition to the public sector.
Fundamentally, hydropower’s enormous potential and incredible dominance in the electricity industry, which essentially has prolonged parturition in the form of capital investment, make it the investment hotspot in Nepal.
Therefore, by weighing the advantages and disadvantages, challenges and chances, and ups and downs of Nepal’s hydropower growth, one may basically identify the greater weight of potential prospects and act accordingly. After carefully examining all the issues, opportunities, and challenges highlighted, it is clear that the collaborative and united efforts of all the various project stakeholders—from the project developer to policymakers and government actors to institutional investors and donor organizations to consumers and electricity users to the project’s target population are essential, fundamental, and unavoidable.
Frequently Asked Questions
Q. Which is the First Hydropower Project of Nepal?
Answer: Pharping Hydropower also known as Chandra Jyoti,500kW marked the beginning of the development of hydropower in Nepal. It was inaugurated on May 22, 1911, by his Majesty King Prithivi Bir Bikram Shah Dev. It was established in 1911. This hydropower uses 2 Pelton turbines.
Q. Which is the largest Hydropower project in Nepal?
Answer: The Upper Tamakoshi Hydroelectric Project (UTKHEP) has been placed into operation in Nepal for quite some time now, with its 456MW potential making it the largest project in hydropower in Nepal.