Sanjen (Upper)
Sanjen (Upper) Hydroelectric Project is a run-of-river scheme with daily peaking facility for 1 hour 10 minutes. The whole scheme is divided into three work sites, viz.Headworks Site that covers diversion weir, undersluice, intake, gravel trap, spillway, desanding basin, peaking pond, forabay and pressure conduit, Underground Works that covers headrace tunnel, rocktrap, surge tank, penstock tunnel and construction adits, and Powerhouse Site that covers surface penstock, powerhouse structure, tailrace and switchyard.
The headworks site is located at Tiloche of Chilime VDC. The headworks consist of overflow diversion weir of height 3.3m and one number of undersluice of size 3m wide and 3m high, side intake structure of 12m long, gravel trap of size 25 m long and 4.2 m wide, dufour type double chamber surface desander basin of size 60m long, 8.5 m wide and 6 m deep, peaking pond of size 138 m long and 65 m wide, forebay and 30m long low pressure conduit connecting to the headrace tunnel portal.
Headrace tunnel is 1378m long, inverted D shape of excavated section 3.5m x 3.75m and will be partly unlined, partly shotcrete lined and partly concrete lined. Surge tank is simple cylindrical type of height 40m and diameter 6m. Penstock is 478m long and mostly exposed type. Surface powerhouse is located at Simbu Village of Chilime VDC. Powerhouse will accommodate three units of horizontal axis Francis turbines of capacity 5.1 MW each and three units of 3-phase synchronous AC generators of capacity 5.85 MVA each. Three numbers of tailrace canals each of 5 m long will discharge the tail water to the Forebay/Intake of Sanjen Hydroelectric Project (SHEP). Surface switchyard is located adjacent to the powerhouse complex.
Generated power from Sanjen (Upper) Hydroelectric Project will be evacuated through a 5km long 132 kV single circuit transmission line to connect from SUHEP powerhouse to the proposed Chilime Hub of NEA and then to the national grid via 220 kV double circuit line up to Trishuli 3B hub of NEA.
Salient Features
| Location | Chilime V.D.C. of Rasuwa district. |
| Developer | Sanjen Hydropower Company Limited |
| Type of Project | Peaking Run-Of-River |
| Hydrology | |
| Catchment area (Dam site) | 180 km2 |
| 90% dependable flow | 2.4 m3/s |
| Design flow (Q40) | 11.07 m3/s |
| Design flood (Q100) | 194 m3/s |
| Geology | |
| Rock Type: | Medium grade metamorphosed schist and quartzite |
| Head | |
| Gross | 161.30 m |
| Net | 156.0m |
| Headworks | |
| Weir | 14 m (l) x 3.30 m (h) |
| Undersluice Single Bay | 3.0 m wide |
| Intake Type | Side Intake |
| Intake Size | 2 Nos, 5.50 m (w) x 1.40 m (h) |
| Desanding Basin | |
| Type | Surface Dufour Type Double Chambre |
| Size | 60 m (l) x 8.5 m (w) x 7.13 m (h) |
| Peaking Pondage | |
| Gross Storage | Capacity 40,000 m3 |
| Normal Water Level | 2347.55 m |
| Headrace Tunnel | |
| Length | 1386.00 m |
| Section | 3.50 m (w) x 3.75 m (h) : D- shaped |
| Surge Tank | |
| Type | Simple Cylindrical |
| Size | 40.00 m (h), 6 m (dia) |
| Penstock | |
| Type | Underground |
| Size | 500 m (l), 1.1~2.5 m (dia) |
| Powerhouse | |
| Type | Surface |
| Size | 46.60 m (l) x 12.00 m (b), 20.00 m (h) |
| Tailrace | 30 m (l) x 3 m (b) x 5 m (h) |
| Turbine | |
| Type | Francis, Horizontal Axis |
| Capacity | 3 Nos., 5.1 MW each |
| Generator | |
| Type 3 | Phase Synchronous AC |
| Rated Power | 3 Nos., 5.85 MVA each |
| Installed Capacity | 14.8 MW |
| Annual Energy Generation | 85.87 GWh |
| Dry Months Energy | 11.02 GWh |
| Wet Months Energy | 74.85 GWh |
| Salable Energy | 82.439 GWh |
| Dry Month Energy | 10.58 GWh |
| Wet Month Energy | 71.85 GWh |
| Transmission Line | |
| Length | 5 km |
| Voltage | 132 kV |