Ngòi Phát Hydropower Expansion Project (Bát Xát District, Lào Cai Province) was developed to maximise the use of inflow at the dam site and reduce surplus water discharged over the spillway. It is a diversion-type plant sharing the dam, intake structure and most of the tunnel with the existing plant. Water is diverted from the existing tunnel. The project began generating electricity in 2020.
The expansion plant tunnel section is 38 m long with D = 3.2 m, located to the left of the existing tunnel alignment. The steel conduit section from its junction with the existing water conveyance system to immediately upstream of the valve house is 95 m long: 38 m lies underground in the tunnel, while the remaining 57 m is exposed and encased in concrete 1.0 m thick.
The exposed steel penstock downstream of the valve house has D = 1.2 m and a length of 373 m.
The expansion powerhouse contains 01 vertical-shaft Pelton turbine unit, with an installed capacity of 12 MW and average annual generation of 20.8 million kWh. Maximum generating head: Hmax = 299.6 m; maximum design discharge through the generating unit: Qmax = 4.98 m³/s.
Contracting entity: Công ty CP Đầu tư và phát triển điện miền Bắc 2
Contract No.: 45A/2017/HĐTV-NEDI2-VCEC
Scope of work:
- Review of basic design.
- Construction supervision and equipment installation supervision.
