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.
With a mandate to promote, develop and maintain major hydropower assets of Bhutan in a sustainable manner, DGPC operates and maintains four hydropower plants with a total installed capacity of 1,480 MW, which are  64 MW Basochhu Hydropower Plant, 336 MW Chhukha Hydropower Plant, 60 MW Kurichhu Hydropower Plant and 1,020 MW Tala Hydropower Plant. DGPC also has shareholdings in the subsidiaries namely 126 MW Dagachhu Hydro Power Corporation Limited (59%) and 118 MW Tangsibji Hydro Energy Limited, and Joint Venture companies namely 600 MW Kholongchhu Hydro Energy Limited (50%), Bhutan Hydropower Services Limited (51%) and Bhutan Automation & Engineering Limited (51%).
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.

Chhukha Hydropower Plant

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.

The commissioning of the project was a defining moment in Bhutan’s history of modern development transforming the Bhutanese economy and generating much needed revenues for the Government. The commissioning of Chhukha Project brought immense benefits to both Bhutan and India. The project provided reliable domestic supply of electricity to the western part of Bhutan and enabled the country to set up many industries such as cement, calcium carbide, ferro-alloy, food processing and many others.

The export of electricity to India helped Bhutan earn the much needed revenue for its socio-economic development activities.

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