HYDRO Nepal Journal – Issue 10(january 2012)

 
Table of Contents
Editorial PDF Pages
Loosing Competitive Advantage in the Water Resources Sector
View PDF 1
Articles Authors PDF Pages
Project Financing in Laos’ Hydropower for Export of Electricity to Thailand
Abstract

Laos, a mountainous and landlocked country, continues to exploit its hydropower potential for export of electricity to neighboring countries such as Thailand, Vietnam and Cambodia. Despite the great development poten¬tial and market opportunities both inside and outside the country, the scarcity of finance for public investment in the power generation sector has been a bottleneck for Lao hydropower. Private investment has therefore been sought and promoted through an independent power producer (IPP) approach which relies on the availability of project funds from the private sector. Currently, six privately-financed hydropower projects operated by private companies are ex¬porting electricity to the grids of Laos’ neighbors. Ten additional hydropower projects developed with private financing are now under construction, and several other projects now under consideration as to their technical feasibility are planned to achieve power-on by 2020.

Keywords: Project financing, limited recourse financing, hydropower, Laos

Xaypaseuth Phomsoupha View PDF 7-10
Water and Hydropower in the Green Economy and Sustainable Development of the Hindu Kush-Himalayan Region
Abstract

Water storage projects in the Himalayan region are thought of primarily in the context of hydropower generation, which can be perceived as an opportunity driven approach. However, water scarcity is a major problem in the basins of the ten rivers originating in the region, especially in the dry season. This is due to high intra-annual rainfall variability, which may get worse due to population growth and climate change and variability. Water storage projects may, therefore, have to be thought of in the context of water scarcity, which can be perceived as a challenge driven approach for water storage capacity development. This paper suggests that to increase the pace of development of constructed storage systems such as large multi-purpose projects that provide water availability as well as hydroelectric power benefits, institutional mechanisms may have to be crafted for benefit-sharing between upstream and downstream communities affected by storage projects. Until that time, it may be necessary to increase the pace of hydropower development in the region through small- and medium-size hydropower projects. This paper discusses the economic, environmental, technological, financial, and institutional barriers to the development of small hydroelectric power plants in the region. It also discusses the role of the Payment for Ecosystem Services (PES) and raising carbon finance under the Clean Development Mechanism (CDM) as potential solutions to partially overcome environmental and financial barriers respectively.

Keywords: Hydropower, green economy, sustainable development, payment for environmental services, carbon finance, Hindu Kush-Himalayan (HKH) region

Ramesh Vaidya View PDF 11-19
Lessons from Paraguay’s 14,000 MW Itaipu Project vis-à-vis Nepal’s 6,720 MW Pancheshwar Project
Abstract

If due diligence is not undertaken on the ambiguities prevailing in the Mahakali Treaty and Letters of Ex¬change of 1996, then Nepal may well end up in a ‘no option trap’ like Paraguay on her 14,000 MW Itaipu, a bi-national hydropower project with Brazil. Twenty-five years after the commissioning of Itaipu, Paraguay is still battling with Brazil on such elementary but vital issues like fair energy price, third party access, parity in project management, etc. Nepal could and should learn lessons from Paraguay’s Itaipu experiences. While Itaipu is primarily a hydropower project, Pancheshwar encompasses wider multipurpose applications. This article, however, limits itself only to the hydropower component of the two projects

Keywords: Hydropower, bi-national treaties, Itaipu Project, Pancheshwar Project, Paraguay, Brazil, Nepal, India

S.B. Pun View PDF 20-23
Tinau River Conservation and Integrated Water Resource Management
Abstract

This paper explores the lives of Tinau River and its inter-dependence with the basin communities and eco¬systems in a holistic perspective. It seeks to share the influences of changing natural and anthropogenic processes on the river-catchment and how the resultant changes in river-basin influence the livelihoods and ecosystems. Taking an integrated approach of river-basin management, it aims to enhance basin-literacy by linking the ongoing processes in river-catchment, land use pattern and human activities.
Without environmentally-sound and sustainable integrated river basin management, it will not be possible to achieve self-sufficiency in food and energy. Tinau River management and conservation must aim to have a healthy river. Each type of water/resource use in the basin is managed in a fragmented manner by a separate department or agency. For healthy watershed development water resources of the river should be managed in a comprehensive manner. Policies, framework, methodology, legislation and institutions are to be developed and established for Inte¬grated Water Resource Management (IWRM) of the river.

Keywords: Basin-literacy, ecosystems, river-catchment, integrated management, Tinau River, sustainable development, Nepal, India

Som Nath Poudel View PDF  24-31
Enhancing Water Productivity in Agriculture at Fokshingkot Lift Irrigation System
Abstract

Ranibas village of Foksingkot Village Development Committee (VDC), Palpa District, Nepal is a severe wa¬ter scarce area. The nearest water source is spring water about 2.5 hours walk downhill (to and fro) to fetch a vessel of water and it is three hours for the farthest household of the area. A lift pumping system consisting of three stages, each of 100m lift and the fourth of 30m lift was (with total lifting of 330m), was constructed to deliver 1.94 liters per sec (l/sec) water for drinking purpose as well as for irrigation of five hectare of land. Despite failures of several lift pumping schemes for irrigation in Nepal, this high head lifting/pumping system has been successful. The 102 households are benefitted with easy availability of drinking water and also for irrigation with drip and sprinkler systems. The lift water supply system has helped in saving time of children and women for fetching water and also increased household income by farming supported by irrigation. The virtual labor saving value of one year surpasses the investment of the project.

Keywords: Lift irrigation, high head pumping, low water required crops, Nepal

Dinesh Rajouria and Padma Prasad Aryal View PDF  32-35
The Potential Role of Water Hyacinth in Wastewater Treatment in Nepal
Abstract

River pollution is one of the significant environmental problems in Nepal. It is primarily due to the direct discharge of sewage from semi-urban and urban areas. The situation is widespread in Kathmandu Valley where the few wastewater treatment facilities are either inefficient or abandoned and modern wastewater treatment facilities are too expensive. The water hyacinth is known as the world’s most unwelcomed flora due to its invasive nature. How-ever, numerous studies revealed many beneficial aspects of the plant species. The plants have already been widely used for different purposes like composting, substrate for mushroom farming, nutritious food for cattle, feed for biogas generation, protein synthesis, fibres for furniture, and for wastewater treatment, etc.
This study investigates the possibility of water hyacinths in wastewater treatment in Nepal. Concentration reduc-tion in BOD5, TN, TP, FC were analyzed weekly for four weeks, and the reduction efficiencies compared with systems without water hyacinth. The experiment resulted in a clear reduction of pollutants/nutrients in the water hyacinth treatment system compared to the system without water hyacinth. In addition, the water hyacinth treatment system was able to remove odour and colour completely, which made the system comparatively advantageous over the system without water hyacinth. It will be beneficial to upgrade existing sewage lagoons in Nepal into water hyacinth systems.

Keywords: Wastewater, water hyacinth, hydraulic retention time, treatment, control, Nepal

Ram Bahadur Singh Maharjan and Chou Loke Ming View PDF 36-41
Design Approach for Sub-surface Flow Constructed Wetlands
Abstract

Constructed Wetlands are an engineered wastewater treatment system that tries to mimic the natural biological, physical and chemical processes to treat wastewater. It is emerging as a cost-effective decentralized wastewater treatment solution in the communities where there is availability of inexpensive lands and lack of skilled operators. Different design approaches have been followed and design parameters based on different literatures have been chosen to design a Sub-surface Flow Constructed Wetlands. A simplified design approach well suited to climatic needs to be developed to maintain the cost effectiveness of the system. The kinetic parameters involved in the treatment should be selected properly in order to get the effective design of the system.

Keywords: Constructed wetlands, wastewater treatment, subsurface flow, kinetic parameters, Nepal

Anish Ghimire, Ajay Kumar KC and Bijay Thapa View PDF  42-47
Numerical Study on Performance Characteristics of Draft Tube of Mixed Flow Hydraulic Turbine
Abstract

Draft tube is an important component of the hydraulic reaction turbine and affects the overall performance of turbine to a large extent. The flow inside the draft tube is complex because of the whirling flow coming out of runner and its diffusion along the draft tube. The kinetic energy coming out of runner is recovered in draft tube and part of recovery meets the losses. In the present work, the computational fluid dynamics (CFD) has been used for flow simu¬lation in complete mixed flow Francis turbine for performance analysis for energy recovery, losses and flow pattern in an elbow draft tube used in Francis turbine at different operating conditions. The overall performance of the turbine at some typical operating regimes is validated with the experimental results and found to be in close comparison.

Keywords: Draft tube, computational fluid dynamics, whirl, efficiency, energy recovery

Ruchi Khare and Vishnu Prasad View PDF  48-52
Tea Plantations in the Darjeeling Hills Geo-Ecological Impact and Livelihood Implications
Abstract

The geo-ecological stability of a place has an important role in contributing to the livelihood security of its people. A disturbance to the geo-ecology of a region jeopardizes the livelihood resources of the population and cre¬ates pressures for livelihood security. Human interventions in the form of destruction of forests and degradation of land significantly alter the geo-ecology of a region. Moreover, interventions with forests result in several other forms of degradations of the geo-ecology of a region. In the light of this understanding, the present study evaluates the impact of tea plantations on the geo-ecology of Darjeeling Hills, India and the consequent impact on the livelihood security of the people in the region.

Keywords: Land resources, land use pattern, livelihood security, geo-ecology, deforestation, landslides, soil erosion, tea, India

Lalit P. Tirkey and Padam Nepal View PDF  53-59
Impact of Sand on Hydraulic Turbine Material:A Case Study of Roshi Khola, Nepal
Abstract

Nepal is endowed by enormous water resources and power potential, but not enough energy has been ex¬ploited from it. One reason is the deterioration of hydraulic turbines. Research on turbine erosion has shown that sand erodes the turbine material. Only a few researches however, have provided details of the many parameters of sand on the degradation of hydraulic turbines. This paper describes the different parameters of sand and the direct impact of sand on turbine material. The study of sand of the Roshi Khola (river) in Nepal shows that mineral content, size, shape and texture are the most important parameters of sand, with different characteristics and their impact on hydraulic turbines. Different methods like using a sieve analyzer to characterize size, microscopic observation after acid wash technique to characterize mineral content, and image processing to characterize and count particle shape are utilized to characterize sand. Sand samples from 20 stations on the Roshi Khola are used in this study. Most of the sampling locations are proposed hydropower project sites and confluences of tributaries. The erosion tests were carried out on turbine material in a High Velocity Erosion Test Rig at Kathmandu University. It was found that hardness, size, and shape are important parameters concerning their effects on erosion of hydraulic turbines. Even a short river like the Roshi Khola shows different sand characteristics at different locations and that they have different erosion rates.

Keywords: Hydraulic turbine, sand particles, turbine erosion, mineral content, Nepal

Laxman Poudel, Bhola Thapa, Bim Pd. Shrestha and Nabin K. Shrestha View PDF  60-65
Increasing and Sustaining Agricultural Productivity through Land
Improvement Approach: A Mitigation Measure to Climate Change
Abstract

Due to greenhouse gas effect temperature around the world will increase (0.06ºC/yr.) resulting in increased Evapo-transpiration and increased need of crop irrigation pressurizing ground water resources and its judicious use. An experiment in a deep tube well area with improved land and irrigation management undertaken in early 1980’s has shown that doubling of agricultural productivity is possible. This system can be taken as mitigative/adaptive measure of climate change.
This paper involves experiences of managing tube well irrigation schemes through improving basically these development parameters in the irrigation command area:
• Land improvement (land consolidation, rectangular shaping and leveling),
• Irrigation canal efficiency improvement,
• Introduction of crop water management, and
• Evolving Farmers Group into a Co-operative Organization- for managing land collectively.
The evaluation has shown that through this intervention approach yields of paddy, wheat, maize and pulse can be doubled in the irrigated areas. This concept might be useful to modify the present policy and program vision of irrigated agriculture development in Nepal through enhancing water productivity a mitigation measure of the effects of climate change. Also, this approach is applicable to surface irrigation schemes of Terai and hills of Nepal.

Keywords: Land rectangulation and consolidation, irrigation, agriculture, Nepal

Rishi Ram Sharma Neupane View PDF 66-72
Evaluation on the Potential Use of Shotcrete Lined High Pressure Tunnel at Upper Tamakoshi Hydroelectric Project
Abstract

Optimization of rock support is a key factor for successful use of underground space for hydropower development in the Himalaya. Therefore, finding innovative, optimum and economic solution will be the only way to guarantee such optimization. A main issue is to determine the extent of hydraulic fracturing and assess the water leakage possibility during the operation of such tunnels. The leaked water not only causes economic loss but also may severely affect the stability of tunnel, valley side slopes and the environment.
The use of fully concrete/steel lined pressure tunnels against hydraulic fracturing in the rock mass is a costly alternative. Hence, it is advantageous to explore possibilities of minimizing the length of the concrete or steel lining in high pressure tunnels and shafts. A proper assessment of hydraulic fracturing of the rock mass plays an important role in this endeavor.
This paper evaluates whether or not hydraulic fracturing (splitting) will occur at the 4,746m long shotcrete-lined high pressure headrace tunnel of 456 MW Upper Tamakoshi Hydroelectric Project (UTKHEP). The Upper Tamakoshi HEP is a high head project (gross head 822m) and the proposed shotcrete lined high pressure headrace tunnel will experience maximum hydrostatic pressure head of 40 bar (400m water column) at normal plant operation. To check the possibility of hydraulic fracturing, both deterministic and two dimensional numerical modeling techniques have been used. In addition, the paper also highlights the importance and challenges to be faced while estimating repre¬sentative input variables needed for both deterministic and numerical modeling.

Keywords: Hydraulic fracturing, high pressure tunnel, shotcrete lining, Upper Tamakoshi Hydropower Project, Nepal

Bibek Neupane and Krishna K. Panthi View PDF 73-80
Book Review: Hydropower Nepal
Jeewan P. Thanju View PDF 81-82
An Interview with Mr. Balananda Poudel, Secretary, Ministry of Energy, Government of Nepal
Mr. Balananda Poudel View PDF 83-85
An Interview with Dr. David Molden, DG, ICIMOD
Dr. David Molden View PDF 86-87

 

Briefing
Topics PDF Pages
Democratizing Electricity in Nepal: NACEUN is Lighting up one Community at a Time
View PDF 88-89
News
View PDF 90-94