1.1 Sources of energy and importance of hydropower
Sources of energy:
- Conventional energy sources
- Conventional sources of energy are those sources which have been use since the early time.
- Their generation and use involve huge expenditure.
- It includes: -Thermal power, Nuclear power, Hydropower
- Non-conventional energy sources
- Non-conventional sources of energy have generally been identified in the recent past.
- Low expenditure required.
- It includes: – Tidal pressure, Hydropower from ocean, Solar power, Wind power, Geo-internal power
Importance of hydropower:
- Economic sources of power
- Renewable sources of energy
- Environmental friendly
- Low generation cost
- Reliable energy source
- Long span of life
- Higher efficiency
1.2 Hydropower development in Nepal
Historical background:
- The first hydropower development or installation in the world was in 1882 A.D and it is in Fox river in Appleton, Wisconsin of USA. The capacity of the first hydropower plant was only 12.5 KW.
- Pharping hydropower plant of 500 KW capacity is the first hydropower plant of Nepal installed in 1911 AD during prime minister Chandra Shumsher Rana’s time to meet the energy requirement of the members of the ruling class.
- The three Gorges dam on the Yangtze river in China is the world’s biggest hydropower with generating capacity of 22,500 MW.
- Upper Tamakoshi hydropower project is the largest hydropower of Nepal with generating capacity of 456 MW.
Main hydropower projects of Nepal:-
| S/N | Hydropower Plant | Capacity | Construction Date |
| 1. | Pharping | 500 KW | 1911 AD |
| 2. | Sundarijal | 900 KW | 1935 AD |
| 3. | Phewa | 100 KW | !969 AD |
| 4. | Devighat | 14 MW | 1983 AD |
| 5. | Kulekhani-I | 60 MW | 1982 AD |
Project under construction:
- Khani Khola-I (40 MW)
- Kulekhani-III )14 MW)
- Middle Modi (18 MW)
- Upper Myagdhi (20 MW)
- Solu Khola (86 MW)
Present development challenges and opportunities:
Challenges:
- Lack of political stability
- No clear plan and policies.
- Government process are time consuming.
- No vision of technology transfer and independency.
- Lack of technology and skilled manpower
- Although Nepal has large potential of hydropower development it does not have its own technology and sufficient skilled manpower.
- The technology and technical equipment’s for quality monitoring and standard specification and norms has not been developed in Nepal.
- The machine and hydro-mechanical equipment production and maintenance facilities had not yet developed fully.
- Lack investment
- The gestation period of the hydropower projects are higher than the payback period.
- Due to lack of stable political system, safety and security their is less foreign investment.
- No beneficial to invest compare to other sector like trade, industries etc.
- Lack of infrastructures
- The feasible and attractive hydropower projects are located in remote areas where physical infrastructure like access road, transmission lines, basic health facilities, other essential skilled manpower and construction materials with equipment availability is very poor or not available at the site.
- Environmental impact
- Flooding land for a hydroelectric reservoir has an extreme environmental impact i.e it destroys forest, wildlife habitat, agricultural land and scenic land.
Opportunities
- Clean energy
- Renewable source of energy
- Pollution free
- Easy to handle and transport from the generating stations to the load centre
- Market available
- Electricity produced in Nepal can be exported to India and China thus helps to reduce trade gap of the nations with these country.
- Used for domestic use in promotion of industrial activities and replacement of petroleum fuel.
- Favorable geological and topographical conditions
- The steep topography with good geological conditions are the favorable and essential for development of hydropower projects at low cost of investment.
- Perennial rivers are suitable for hydropower production.
- Availability of cheap labor force
- Nepal has developed a lot of engineering institutes and technical centers and have produce many skilled and semi-skilled manpower which are available at cheap rate compared with development countries.
1.3 Hydropower potential in Nepal
- Nepal’s huge hydropower potential is due to many perennial rivers.
- The major river basins are Koshi, Gandaki, Karnali and Mahakali.
- Total annual surface runoff including the flow from Tibetian drainage = 200 Billion m3
- Average precipitation= 150 mm (80% during monsoon)
- Flow density 0.3 Km/m2
- Gross potential = 85000 MW
- Technical potential = 44000 MW
- Economic potential = 42000 MW
Type of hydropower potential
- Gross potential (Theoretical)
- The power which can theoretically possible to generate.
- Gross potential (P) = ηρQH
Where,
η = Efficiency
ρ = Unit weight of water = 9.81 KN/m2
Q= Discharge (m3/s)
H = Total head (m)
P = Power (KW)
2. Technical potential
- All the theoretically possible power in nature cannot be produced due to unfavorable geology, topography, climatic condition. So, the power which is technically feasible to produce is known as technical power potential.
3. Economic potential
- All technically feasible projects cannot be implemented unless it provides low-cost electricity and durability over time compared to other sources of energy.
1.4 Introduction to some largest hydropower plants in the world
| S/N | Hydropower plant | Capacity | Country |
| 1. | Three Gorges | 22,500 MW | China |
| 2. | Itaipu | 10,300 MW | Brazil |
| 3. | Guti | 6,900 MW | Venezuela |
| 4. | Grand Coulee | 6,900 MW | USA |
| 5. | Bela Monte | 11,233 MW | Brazil |
| 6. | Bratsk | 4,500 MW | Russia |
| 7. | Tucurui | 8,400 MW | Brazil |
1.5 A brief introduction to government policy and major institutions related to hydropower development in Nepal
Hydropower development policy
Objective:
- To generate electricity at low cost by utilizing the water resources available in the country.
- To extend reliable and qualitative electric service throughout the Nepal at reasonable price.
- To develop hydropower as an exportable commodity.
Provision for hydropower development policy (2001)
- Environmental provision
- Provision concerning water right
- Provision for investment in generation, transmission and distribution
- Provision related to transfer of project
- Provision related to power purchase
- Provision on license
- Institutional provision
Hydropower development institution in Nepal
- Ministry of energy (MOE)
- A government body of Nepal that governs the development and implementation of energy including its conservation, regulation and utilization.
- Water and energy commission and its secretariat (WECS)
- To assist government and different ministries relating to water resource and other related agencies in the formulation of policies and planning of projects in the water and energy resource sector.
- Electricity tariff fixation commission (ETFC)
- The role of ETFC is to fix electricity tariff and other charges of electricity supplied and distributed by the license or Government of Nepal.
- Department of electricity development (DOED)
- Responsible for assisting the ministry for implementation of overall government policies related to power/electricity sector.
- Nepal electricity authority (NEA)
- The role of NEA is to generate, transmit and distribute adequate, reliable and affordable power by planning, constructing, operating and maintaining all generation, transmission and distribution facilities in Nepal’s power system both interconnected and isolated.
- Independent Power Producers Association Nepal (IPPAN)
- The role of IPPAN is to act as a link between private sector and government organization involved in developing hydropower in Nepal.
- Nepal Micro Hydropower Development Association (NMHDA)
- The role NMHDA is to develop and promote the use of micro-hydro technology.
References:
- A text book of fluid mechanics and hydraulic machines, Dr. RK Bansal, (2008), Laxmi publication(P) LTD.
- Hydropower Engineering Handbook – John S. Gulliver & Roger E. A. Arndt