Generation, Operation and Maintenance

Generation Operation and Maintenance

Devighat Hydropower Station

Devighat Hydropower Station is the cascade hydropower station of Trishuli power station. It is located at Devighat, Nuwakot with installed capacity of 14.1 MW and annual design generation of 144 GWh. It was commissioned in 1984 AD and developed in assistance from Government of India and Government of Nepal with the total cost of NRs. 750 Million including transmission line. The rehabilitation of all the three units at a cost of INR 338.15 million was successfully completed by the contractor BHEL and handed over to NEA on July 13th, 2011. The capacity of the units is improved and presently, all the three units are in normal operation. The operational capacity is based on the availability of the flow released from the upstream Trishuli Hydropower Station.

After the successful completion of RMU project in Devighat in fiscal year 2010/11, the generation has been satisfactory and is limited only by the obstacles in generation faced by upstream plant of Trishuli in one of its unit.

The cumulative generation of Devighat HPS has now reached 2309.38 GWh till 2011/12 from its first run. This station generated 74.13 GWh in FY 2010/11 and 105.09 GWh in FY 2011/12 with an increase of 41.76%. The generation from this station contributed 1.92 % and 2.51% of the total energy to the INPS in FY 2010/11 and 2011/12 respectively.
Type Cascade of Trishuli Hydro Power Station
Location Charghare VDC, Battar Municipality, Nuwakot District
Installed capacity 15MW (after rehabilitation)
Annual average energy 114 GWh
Maximum Net head 40.5m, 39m
Catchment area 4150 km2 (upto Trishuli diversion)
Average annual flow 40.5m, 39m
Maximum Net head 45.3 m3/s
Dam
Total length of the waterways 4.5 km from Trishuli HPS tailrace to Devighat HPS forebay
Penstock 3 Nos., Ø2.5m, steel lined
Turbine
Number and Type 3, Vertical Francis
Rated discharge 14.3m3/sec
Rated output 5.03MW
Rated speed 333.3rpm
Generator
Rated output 6.25MVA
Rated voltage 6.6kV
Rated frequency 50Hz
Power factor 0.8
Power transformer 6.3MVA, 6.6/66kV, 3-phase, 3 Nos.
Transmission line 66kV, 37km(Devighat -Chabel), 28km(Devighat - Balaju), Double circuit