25MW Nepal Hydro Power.Pdf
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www.sumecgeopower.com TR-SGP Hydroelectric Project [email protected] Updated Feasibility Study Report www.sumec.com Main Report, Volume I EXECUTIVE SUMMARY Introduction Nepal is endowed with vast water resources potential but only tiny fraction of technically and financially viable project are harnessed so far from Government of Nepal and through private sectors. Stef Energy India P. Ltd (herein referred to as Client) is established to develop TR-SGP Hydroelectric Project (TR-SGP) and the Upgraded Feasibility Study service was awarded to SGP IMASS (SGP) (herein referred to as Consultant). As a part of the agreement, SGP IMASS has carried out the Feasibility Study of the said project located in Richowktar, Malekhu, Dhading, Central Development Region, Nepal. This Feasibility Study Report is prepared by the Consultant as per the Terms of Reference (ToR). Findings from the literature review, site visit, topographical survey, field investigation and analysis of data are the basis of preparation of this report. The feasibility study formed a basis whether or not to conceive the TR-SGP a feasible project to develop. Technical A design discharge of 127.91 m3/s for power generation is diverted through a side intake located some distance upstream from the diversion weir. The project is conceived as a small regulating pond created by constructing about 12 m high concrete dam. The head pond will be extended to a distance of about 2 km upstream from the proposed dam. The dam is envisaged to be founded on bed rock but do not have high quality. There are 6 gates will be construction in the dam itself so that there will be free flow spillway type diversion dam available. The extreme flow to be handled is extensively high and thus ungated overflow spillway is designed. The gates will be operated from left bank. Both banks has exposed rock. The intake will have a flood wall and collection chamber just behind to ascertain smooth transition of flow from intake to bell mouth of the headrace tunnel. The flow than convey through a headrace tunnel of diameter of 8 m finished surface, 3730 m long to the powerhouse. An intermediate adit is located at Bhante Khola, which infact the tunnel is opened at Bhant Khola. Level crossing is proposed to connect the tunnel heading. Orifice type surge shaft, 20 m at top and 10 m at bottom is designed to address surge effect of the system. A relatively short penstock pipe is designed to convey design flow to the powerhouse. About 30 m long 7300 mm pipe will lead flow from the tunnel and will be branch off once it comes out outside the tunnel. The twin penstock pipe will be about 40 m long 5600 mm diameter will convey the flow to four units of turbine. HydroPower_Nepal.docx i 15 Jan 2015 www.sumecgeopower.com TR-SGP Hydroelectric Project [email protected] Updated Feasibility Study Report www.sumec.com Main Report, Volume I The powerhouse is located in flat land and will be equipped with 4 units of vertical Shaft Type Kaplan Turbine. Each penstock pipe will feed two turbine units. Each unit will have 6.25 MW output and an annual energy generation is 163.32 GWh, with dry energy of 35.35 and wet energy of 127.97 GWh. The gross head of the plant is 29.5 m. Geology of the tunnelling part is envisioned to be poor and thus a full permanent lining is felt necessary. Generated power from the TR-SGP will be evacuated through the 132 or 220 kV planned T/L to Naubise where the interconnection point will be at Gomati, Benighat, Dhading, which is about 750 m from the proposed powerhouse. Environment An IEE of the project has been approved on Feb 2011 and the findings and observations show that there are no adverse environmental impacts by this project. However, a mitigation measures as proposed in the IEE report should be implemented to ascertain sustainable development of the project. Economical and financial analysis Economical and financial analysis of the TR-SGP has been carried out to ascertain the economical and financial viability of the scheme. The technical feasibility of the scheme has been established through studies carried out on each of those aspects. Furthermore, the project cost includes separate costs for major mitigation costs associated to the TR- SGP, land acquisition and community developments in the project area. The analysis has been carried out based on marginal cost benefit approach for the adopted scheme based on economic and financial parameters deemed to be realistic and standard for analysis of this nature. A sensitivity analysis has been carried out by varying some of the assumed economic and financial parameters. Economical analysis of the project was also carried out to ascertain economical prospective from the nation. It was looked a project life span of 50 years excluding taxes, royalties, but with the inclusion of very tentative benefit accrued from the project. It is extremely difficult to quantify the exact benefit that is accrued from the project since people living in and around the project area will be benefited in many respects during construction of the project too. The total project construction cost is estimated as MNRs 5,489.62. For a 70:30 debt equity ratio and 7% interest over debt financing, the total project financing cost is comes out as MNRs 5,864.68. Construction period is assumed to be 3 years. The financial HydroPower_Nepal.docx ii 15 Jan 2015 www.sumecgeopower.com TR-SGP Hydroelectric Project [email protected] Updated Feasibility Study Report www.sumec.com Main Report, Volume I indicators for the project for this scenario are IRR 14.57%, and payback period is 5 years. The energy tariff for dry and wet energy is taken as NRs 8.4 and 4.8 /kWh respectively The sensitivity analyses shows that the project is financially and economically sound if two or more different unfavourable conditions as discussed in sensitivity analysis will not occur simultaneously. Feasibility study report structure The Updated Feasibility Study Report is prepared as the last deliverable for the study conducted by the Consultant. It complies and presents data/information collected, findings, project layout, main design parameters and financial indicators of the project. The report comprises of main report including appendices to support main report. The feasibility report is presented in the following format: Update Feasibility Study Report ! Volume I Main Report ! Volume II Detail Geological Report ! Volume III Annexure • Annex A Data on Hydrology • Annex B Cost Estimation • Annex C Financial Analysis ! Volume IV Appendix E Drawings ! Volume V Field Investigation Report Conclusions The 25 MW TR-SGP project is found technically feasible, economically and financially viable, and environmentally friendly. The headworks area of the project is almost close to the all season blacktopped road. All key project areas are connected to main road by track opening, a minor upgradation will avail accessibility to the project site. Recommendations The project is recommended to pursue further. However, following activities are recommended during different development stages of the project: ! The TR-SGP is found technically sound financially attractive. However, wherever possible two extreme cases should be avoided to ascertain better project attraction. HydroPower_Nepal.docx iii 15 Jan 2015 www.sumecgeopower.com TR-SGP Hydroelectric Project [email protected] Updated Feasibility Study Report www.sumec.com Main Report, Volume I ! The uncertainties as identified during filed geotechnical filed investigations are recommended to be pursued during detailed design phase of the project. ! It is highly recommended to establish a gauging station most likely around powerhouse area and later on move it upstream of dam, once the project is decided to implement. ! Minimum three sets of permanent points to be established at key project area and the points are to be transferred from 2nd and 3rd order grid available in the area; ! Model study of the project is suggested to carry out during detailed design phases of the project. ! Customised design will be required for the powerhouse electromechanical equipment in order to minimise the cost of powerhouse and also to other components of the power plant. It is thus recommended to award the Electro- mechanical contract to a highly experienced manufacturer/supplier. ! Preliminary assessment on power transmission to 132 or planned 220 kV transmission line passing close by the project showed a better option to the project financial attractiveness. This issue should be discussed with NEA and sorted out the possible power evacuation mode of the project. The study, however, recommend to evacuate the generated power at Gomati using PI connection. ! Regarding environmental issues, there could be only short-term problems may be encountered during construction of the project. An effort has been made to minimise those problems in the design. Moreover, additional issues that may be raised by the IEE study will be incorporated in the detail design and construction phases. The cost associated with those short terms problem is estimated and included in the project cost estimation. ! Pre-construction activities such as financing negotiations and documents for detailed design stages should be initiated. ! A full risk analysis for project life cycle (RAMP) should be carried out to determine the associated risk and its effects on the project before detailed design. Table of contents Page no. HydroPower_Nepal.docx iv 15 Jan 2015 www.sumecgeopower.com TR-SGP Hydroelectric Project [email protected]