Installed capacity     : 4×84 MW
Design energy            : 1,800 MU
Project scheme          : Run off the River
Project commission: 1986 – 1988

The 336 MW Chhukha Hydropower Plant (CHP), located at Chhukha dzongkhag in the south-western part of Bhutan, is the oldest power plant (profit centre) of Druk Green Power Corporation Limited (DGPC). DGPC is a wholly owned subsidiary of Druk Holding and Investments Limited established in 2008 with the merger of the erstwhile hydropower corporations in the country.

Chhukha Hydropower Plant was then the largest and the most prestigious bilateral project to be considered by the Royal Government of Bhutan (RGoB) and the Government of India (GoI).

His Majesty Jigme Dorji Wangchuck, the Third King of Bhutan envisioned the development of hydropower for lighting of homes, setting up industries within Bhutan and also for earning revenue from export of surplus power to India. This vision of His Majesty’s was fulfilled by His Majesty Jigme Singye Wangchuck, the Fourth King of Bhutan, when the agreement for Chhukha project was signed between the RGoB and GoI. CPA was constituted to implement the Project. Both the dam and powerhouse are at an offset of about 6 km from Tsimasham town and 3 km from Chhukha Zero check point on the Thimphu-Phuentsholing highway. A 40 m high diversion dam is used for diverting the water for generation of electricity. Four spillways gates are used for discharging the excess water. Water from the diversion dam is conveyed through 6.5 km tunnel.

Salient Features

Historical Development

Operation Highlights

Financial Performance

Renovation and Modernisation

Although designed to generate 336 MW with provision for 10% overloading during the monsoon, the original Tail Race Tunnel restricted the generation to 320 MW only. An additional TRT was constructed in 1995 to enable full generation with 10% overloading during peak season.

With the diversion of Tichhalumchhu into the dam and Lubichhu into the surge shaft in 2009, the overall CHP energy generation was augmented by 67 MU annually by utilising the additional water during lean months. In order to overcome problems associated with ageing and obsolescence of spares and support services, and also to improve efficiency and reliability, renovation and modernisation (R&M) works were initiated in 2006. R&M was carried out mainly on the governing system, excitation system, circuit breakers, distance protection system and brackets for generators.

Replacement of stators, upgradation of protection system from electro-mechanical to numerical system and installation of supervisory control and data acquisition (SCADA) system are underway.

Socio-Economic Benefits and Sustainability

Although designed to generate 336 MW with provision for 10% overloading during the monsoon, the original Tail Race Tunnel restricted the generation to 320 MW only. An additional TRT was constructed in 1995 to enable full generation with 10% overloading during peak season.

With the diversion of Tichhalumchhu into the dam and Lubichhu into the surge shaft in 2009, the overall CHP energy generation was augmented by 67 MU annually by utilising the additional water during lean months. In order to overcome problems associated with ageing and obsolescence of spares and support services, and also to improve efficiency and reliability, renovation and modernisation (R&M) works were initiated in 2006. R&M was carried out mainly on the governing system, excitation system, circuit breakers, distance protection system and brackets for generators.

Replacement of stators, upgradation of protection system from electro-mechanical to numerical system and installation of supervisory control and data acquisition (SCADA) system are underway.

Organogram

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