Hydro Electricity Power
Water is the most important source of energy in Bhutan. The first hydropower project in Bhutan was constructed on the Samteling Chhu in Thimphu. This mini-hydro electric plant was commissioned in 1967. Then, the construction of smaller hydro and the use of diesel engines to produce electricity in remote towns followed. During the 1970s, Bhutan and India began to look more closely into channelling the hydropower potential. Thereafter, the development of hydropower is initiated.
Today, electricity is much more widely available in Bhutan. The development of more than 20 hydroelectric schemes as well as the installation of diesel generators has made it possible to electrify more than 40 towns and 1,064 villages (2004) within a short period of time. Bhutan continues to harness the immense hydropower potential that Bhutan is endowed with. Today, the sector contributes nearly 40 percent of the domestic revenue. Some of the important hydropower developments in the sectors are:
This project was commissioned in 1988. It is a joint venture between Bhutan and India. It is located in Chhukha dzongkhag. It was the first biggest investment project Bhutan had ever seen. The project was constructed with Indian assistance and financed at a cost of Nu. 430million. It is located on the left banks of the Wang Chhu. It has a 6.5 Km long tunnel and the water drops from a height of 425 metres to the turbines. There are four turbines, each with a capacity of 84mw. The powerhouse consists of an underground cavern hollowed out nearly 400m inside the face of the cliff. The Chhukha power project is made available to the districts of Chhukha, Thimphu, Paro, Punakha, Samtse etc. The power is also exported to Sikkim, Bihar, Orissa and West Benga in India. The National Revenue Report of 2005-2006 reveals that Chukha Hydropower contributed Nu. 2,092.682 million, a figure that consists of 30.01% of the total revenue of Bhutan. The receipts during the year showed an increase of 8.75% or Nu. 168.395 million From the previous year’s collection.
The Kurichhu Hydropower Corporation was commissioned in April 2001; three units of 15mw each was commissioned in April, August and September in 2001 and fourth unit in May 2002.
The project was constructed with a budget of Nu. 5,600 million from the Government of India and Nu. 40 million from the Royal Government of Bhutan. The Government of India provided a 60 percent grant and a 40 % loan at 10.75 % interest per annum.
It consists of one dam and is constructed across the river Kurichhu, about 100m upstream to the power house. The dam is built of concrete-gravity. The Kurichhu dam is 285m long, 8m wide and 55m high (from the deepest foundation). There is only one reservoir with a storage capacity of about 15.7 million M3 at full reservoir level. The length of the reservoir is 6.7 Km and the breadth varies from 100m to 350m. The reservoir is flushed out twice or thrice a year depending upon the silt content in the river as well as during line shut-downs. The excess water is diverted from the spill-way operated by spill way radial gates. There is only one powerhouse. It is located 100m away from the dam. This powerhouse has the capacity to produce 60mw of hydro electricity. The Kurichhu power is made available to the districts of Mongar, Lhuentse, Trashigang, Trashiyangtse, Pema Gatshel, Samdrup Jongkhar, Sarpang, and Zhemgang and in the near future is expected to reach Trongsa and Bumthang. The Kurichhu hydro power is also exported to India i.e. West Bengal and the Damodar Valley Corporation.
The Basochhu power plant is located near Wangdiphodrang. It was constructed with technical and financial assistance from Austria. The production capacity of this project is 24mw. This project was known as the Basochhu Project Authourity (BPA) but was later re-named the Basochhu Hydro Power Corporation as of January 2003. It uses a steep fall to produce electricity. Electricity generated from this fully computerised plant is expected to fulfil the demands of the surrounding communities and even Thimphu. Approximately Nu. 1065 million out of the estimated project cost of Nu. 1,422 million has been spent.
This project is located at Tala- a few kilometres downstream from the Chhukha plant. This project has the capacity to generate 1,020mw of electricity. To harness the waters of the Wang Chhu, around 40 kilometres of tunnel – some with diameters of 8 metres were constructed. It is estimated that the project has deployed a workforce of 10,009 of whom 1,565 are Bhutanese and 8,494 are Indians. The net drop of 860 metres into the turbines has converted Tala’s diverted water flow into a major source of energy and national income. It was fully commissioned in 2007.
There are many small hydropower plants in Bhutan catering to remote villages which are not linked to the main electricity distribution grid. The small hydro projects have significant roles to play in our economy. For example, small hydro at Rangung, which has an installed capacity of 2.2mw, fulfils the demands from the neighbouring towns and villages. The other examples of such hydro plants are the 0.390mw Khalanzi at Mongar and the 0.300mw plant at Wangduephodrang. Today, the Chhukha Hydropower Corporation Ltd, Basochhu Hydropower Corporation Ltd. and the Kurichhu Hydropower Corporation Ltd. have been renamed the Chhukha Hydropower Plant. The Basochhu Hydropower Plant and the Kurichhu Hydropower Plant have been regrouped into one body under the aegis of the Druk Green Power Corporation Ltd.