Study of the status of hydroelectricity in Nepal. 

Introduction

Hydropower is one of the renewable sources of energy in the world. It is achieved by converting the kinetic energy of water into electrical or mechanical energy. In the context of Nepal, it has been blessed with a large amount of freshwater, i.e. about almost 2.7% of the world’s freshwater.

Nepal is the second country after Brazil with more water reserves. Hydropower is the main source of energy in the context of Nepal, with nearly 90% installed capacity and about 90% generation of electricity. Thus, hydropower is an eco-friendly source of energy with no pollution emitting in the air or inland and is also the most effective method for all.

Talking about history, the first use of hydropower was done by Richard Arkwright, in the Cromford Mill in England’s Derwent valley in 1771. But the world’s first hydroelectric power project was developed at Cragside in Northumberland in 1878, England by William Armstrong. Likewise, in the context of Nepal hydropower development was initiated on May 22, 1911, i.e. (9^th Jestha 1968 BS) by installing 500kW electricity at Pharping named Chandra Jyoti. After a long duration of 25 years, Prime Minister Dev Shamsher initiated a 640 kW, Sundarijal Hydropower plant with a capacity of 900 kW in 1936.

Sundarijal hydroelectricity development was once again stopped for decades. Again Morang Hydropower Company, established in 1939, built a 677 KW Sikarbas Hydropower plant at Chisng Khola in 1942 though this Plant was fully destroyed by a landslide in the 1960s. Nepal Electricity Corporation (NEC) was established in 1962 and was given the responsibility of transmission and distribution of electricity in Nepal.

After a long gap, the hydropower generation capacity of the country was prolonged with the construction of the Panauti Hydropower plant (2400 KW) in 1965 and the Trishuli Hydropower plant (24000 KW) in 1967. Recently the biggest hydropower of our country, 'Upper Tamakoshi Hydropower Project' of 456MW is in the final stage and all units are already tested and passed.

As we know, hydropower has a large potential in the context of Nepal. The country's appraised hydropower potential is to be upwards of 50,000 MW - actual electricity generation from hydropower in Nepal is currently 800 MW from 20 major hydropower plants and numbers of small and micro hydropower plants. Altogether, 6000 rivers counting rivulets and tributaries are present in Nepal.

In this way, it offers a great potential for hydropower development in Nepal while storage capacity is 202,000 million. The hydropower system is influenced by run-of-river systems in Nepal while storage scheme has been benefited to control flood, provide irrigation facility, drinking water supply, navigation, recreation, tourism, aquaculture, food security, health security, energy security, preserving the environment, and generate bunce. Nepal can generate bunce of up to Rs.310 billion per year in 2030 and as high as Rs1,069 billion per year in 2045 if the country is able to sell electricity to India to mobilize its hydropower potential.

Nepal Electricity Authority has a total installed capacity of about 746 MW and 26 MW operating from mini and micro hydropower plants in the hills and mountains of Nepal. This way Nepal has huge scope in the sector of hydropower development.

Having a theoretical potential of nearly 90,000 MW hydropower at least 42,000 MW is technically and economically feasible. Unfortunately, Nepal is utilizing only 2% of it (i.e., 98% remains unutilized). On the other hand, over 60% population do not have access to grid-connected power in Nepal. Moreover, the annual growth of power demand (grid-connected) is over 10%. During the lean season, the power shortage becomes so acute that NEA needs to ration the power up to 12 hours each day. Nepal's prosperity is certainly dependent on the utilization of its hydro resources. However, it does neither have financial resources nor technical know-how to explore the full potential of hydro resources. For large-scale investment in hydropower projects, Nepal needs to attract foreign sovereign and private investments as well as markets for power sale.

Methodology of production of hydroelectricity.

Hydroelectricity is produced by utilizing the gravitational force of falling water. To this end, the hydropower plant requires a dam. This dam is placed on a source of water, preferably a river. The dam is a massive wall that blocks the flow of the river, therefore, a lot of water collects behind the dam. Near the bottom of the dam, there is an intake from which the water is let into the dam. This intake leads to a drop through the penstock inside the dam. The device used to obtain energy from the falling water here is a turbine. Thermal power plants also use turbines but there are some major differences between steam turbines and hydro turbines. The turbine is connected by a shaft to the generator. When the water rotates the turbine, electrical energy is generated.

Hydropower plants also have a facility of pumped storage wherein water is kept as a reserve for periods of peak power demand. This is the hydroelectric equivalent of recharging your battery. When the power demand is low, say in the middle of the night, the dam uses a pump to pump the water back up to the reservoir behind it. This water is then used during times of peak power demands.

The process of production of electricity is quite simple. Which can be written as follows.:

1.      A dam is created, which is very high.

2.      The water is let through a tube which is normally slanted at a certain degree.

3.      The water let through the tube is at very high pressure and at a very high speed, the high pressure is due to the small-sized tube.

4.      The high speed and pressured water hit the turbine which is kept at the end of the tube, forcing the turbine to rotate.

5.      Now the turbine is connected to the generator, or we normally call it a motor. A motor and generator are quite the same but does the work exactly different. Exactly different in the sense that the motor uses electricity to rotate things whereas the generator uses rotated things to generate electricity.

This is a coil that is normally used in a motor and a dynamo/generator. Where there is a magnet in the center (i.e. the hollow part).

Now the difference between the dynamo and the motor.

In a motor, the coil is charged with electricity, forcing in the electric charge, which then makes the coil act as a magnet. The magnet at the center rotates because the coil acts as the opposite pole to that of the magnet. Which makes the rod connected to the magnet rotate as well and things connected to it rotates.

Whereas in a generator/dynamo, the rod connected to the magnet is rotated in such a way that the magnet rotates, creating a magnetic flux, the flux then forces the electrons in the coil to move. The moving electrons, create a charge which is then extracted using a simple kind of wire. Hence, that is how we produce hydroelectricity.

Observations

From the theory and the methodology we used, we can find the way to produce electricity and the total capacity of the production of hydroelectricity in the context of Nepal. Hydropower can play a vital or major role in addressing increasing demand worldwide for clean, reliable, and affordable energy. In the present scenario, 733 MW out of 782 MW installed capacity is hydropower. All over 478 MW of hydropower capacity is NEA-owned, while 255 MW is privately owned and manipulated. However, the installed capacity is 1,128.69 MW as of 2019 data, and over 20 % of Nepalese remain deprived of grid electricity. The current peak load of electricity demand is 1,320 MW, while annual energy demand has increased by 9% and is expected to increase to 2,379 MW by 2022 and 4,280 MW by 2030.

Results/ conclusions

Learning the concepts of the production and the total amount produced in the context of Nepal, we can finally conclude that, Nepal is producing a lot less hydroelectricity than it should actually be producing. Hence, the status of hydroelectricity in Nepal isn’t quite good.