In the picturesque landscape of Phaktanglung Rural Municipality, nestled within the embrace of Taplejung District, Province 1, Nepal, unfolds the Tamor Khola-5 Hydropower Project (TK5HP). Owned by River Side Hydro Energy Private Limited (RSHEPL), this project, with its 37.5 MW capacity, taps into the rhythmic flow of the Tamor River, a vital tributary of the Saptakoshi River.
Embarking on a Dynamic Evolution
The TK5HP narrative commenced with the issuance of a survey license on Ashwin 29th, 2074 B.S. (15th October, 2017 A.D.), marking the genesis of a 37.52 MW powerhouse. The subsequent Power Purchase Agreement (PPA) inked with Nepal Electricity Authority (NEA) in 2075 B.S. underscored the commitment to producing 219.65 GWh, a harmonious blend of wet and dry energy.
Yet, geological intricacies prompted a reevaluation of the powerhouse’s location. Collaborative efforts between RSHEPL and Sanima Hydro and Engineering Pvt. Ltd. (SHEPL) unfolded a meticulous Feasibility Study Review (FSR), Due Diligence Study (DDS), and Detailed Engineering Design (DED). This partnership led to a pivotal decision to relocate the powerhouse downstream, optimizing both topography and geology.
Navigating Change for Optimal Design
In response to the need for resizing and layout modifications, a new contract agreement was penned on May 10th, 2020. The objective was clear: elevate the project’s gross head, mitigate hydrological risks, and achieve optimal design modifications. The revised detailed engineering design considered an updated gross head of 98 m, a significant ascent from the initial 80.68 m.
Sensitivity analyses were conducted, culminating in an optimal design discharge of 47.5 m³/s, delicately balancing flow exceedance and project optimization. The reimagined layout promises robust energy generation of 230.97 GWh, strategically divided between wet and dry seasons.
A Symphony of Site Insights and Geological Revelations
March 2022 witnessed a meticulous site visit, offering invaluable insights into the new powerhouse location. Detailed topographical surveys and geological surface mapping were conducted to ensure the feasibility of the updated project layout. The powerhouse area, nestled in a debris deposit zone, posed challenges but also revealed opportunities for stabilization and optimization.
The geological tapestry, comprising silty sand to clayey sand with gneiss clasts, underwent thorough scrutiny. An active creeping landmass south of the powerhouse area underscored the importance of stabilization before breaking ground. The optimized powerhouse and surface penstock design now harmonize seamlessly with the topography and geological nuances.
Conclusion: Forging a Path to a Sustainable Tomorrow
The Tamor Khola-5 Hydropower Project stands as a testament to adaptability in hydropower development. From initial challenges to revised layouts, RSHEPL, in collaboration with SHEPL, navigated complexities, ensuring not just energy generation but a sustainable and optimized future. As the project progresses with its updated design, it symbolizes a commitment to responsible development, environmental harmony, and a brighter energy landscape for Nepal.