Hydroelectric Power Generation Requires Seamless Geo-support that only come across Himalayan Kingdom of Bhutan

Fig-1: Principle of Hydroelectric Power Generation

What salient feature is required for seamless hydroelectric power generation that Bhutan encompasses?

Hydroelectric power generation is the topper power generation system considering the environment-friendly green energy generation. Hydroelectric generation is also one of the cheapest electrical energy production methods.

The limitation of hydroelectric energy generation mostly depends on the natural geographical location that Bhutan can meet naturally. Topographic facilities to generate hydroelectric energy may change Bhutan’s economical position, just exporting the surplus electricity to neighbours’ countries like India, Bangladesh etc. 

Bhutan’s river system, means huge water resources are mainly in the form of rivers. There are a few lakes, but they are mostly small and are mainly located in the remote high altitude alpine areas and are not much of economic utility. Some of these lakes are glacial lakes and outbursts of these lakes from time to time have resulted in enormous flash floods and damage to lives and property. 

As per the topography of the country, the major rivers flow north to south with their sources in perpetual snow cover and flowing right down to the tropical zone on the border with India.

While most of them originate in Bhutan itself, a few of them have originated in China. These rivers have steep longitudinal gradients and narrow steep gorges, which occasionally open up and provide broader valleys with small areas of flat land for cultivation.

Some of the main rivers have cut 1000 m deep valleys through the mountains. The majority of the valleys are narrow V-shaped valleys indicating that water erosion has been the main cause of their formation.

Due to the steep longitudinal gradient and the high annual runoff, these rivers provide significant hydropower potential with an estimated theoretical potential of 30,000 MW. 

Due to the existence of distinct rainy and dry seasons, there are large seasonal variations in the river flows. These rivers carry large volumes of flow and often also sediment during the monsoon season, whereas the flow is relatively low during the dry season due to the limited rainfall and the limited existence of major groundwater reservoirs.

Snow-melt from the high altitude alpine areas in the north contributes to the flow at the end of the dry season.

Apart from the major north-south flowing rivers, Bhutan conferential and rain-fed tributaries that flow do often as waterfalls to join the main rivers.

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What makes Bhutan a unique hydroelectric energy potential country?

Bhutan’s water resources are confined to four major river basins which originate from the high altitude alpine area and from the perpetual snow cover in the north and flow into the Brahmaputra River in the Indian plains. 

BASIN-I (Comprises of Amochhu and Wangchhu Basin): It is the smallest of the river systems also known as Torsachhu. It has its origin in the Chumbi valley of Tibet and flows through the western districts of Haa and Samtse before draining into the plains of India. It consists of three major tributaries from the three valleys of Thimphu, Paro and Haa. They originate within Bhutan from the glaciers and snow-capped mountains in the north. It flows through Chukha District to the Indian plains of West Bengal.

BASIN-II (Punatsangchhu Basin): Also known as Sankosh Chhu, consists of two major tributaries Phochhu and Mochhu that originate from the Gasa district. The two rivers join at Punakha Dzong to become Punatsangchhu (Sankosh) that flows through Wangdue Phodrang, Tsirang and Sarpang Districts before reaching the Indian plains.

BASIN-III (Manas Basin): It is the biggest river basin and drains almost all the catchments of Central and Eastern Bhutan. It consists of four major sub-basins:

Mangdechhu - originating close to Gangkhar Punsum (Among Bhutan’s highest peaks at 7239m);

Chamkharchhu       - originating close to Gangkhar Punsum;

Kurichhu - originates in China;

Drangmechhu - originates from the north-eastern part of Trashiyangtse, Arunachal Pradesh in India and China.

Bhutan has three regions distinctly different due to prominent north-south mountain ranges that separate each area resulting in different topographical features:

Western Bhutan: Comprising of Haa valley, Paro valley, Thimphu, Punakha valley, Wangdue Phodrang and high passes or La’s: Cheli La, Dochu La & Pele La which separates Western Bhutan from Central Bhutan;

Central Bhutan: the Black Mountains separate Western Bhutan from Central Bhutan. This region includes Trongsa and rich valleys of Bumthang, including Chumey;

Eastern Bhutan: This region comprises Mongar, Lhuentse, Trashigang and Trashiyangtse. Senior valley separates Central from Eastern Bhutan. The altitude here is much lower than in the other regions.

What is the Exceptional Hydroelectric friendly geo-location of Bhutan?

Fig-2: A Perfect Water Reserve Dam for a Hydroelectric Power Plant

The Himalayan Kingdom of Bhutan, by virtue of its geographical location on the southern slope of the Eastern Himalayas, is blessed by nature with attitudinal varying landmass with good vegetation cover, the perennial flow of water in the swift-flowing rivers and fair climatic conditions.   

Bhutan is a land-locked country bordering China in the North and India in the West, South and East. Bhutan lies between latitudes 26.7°N and 28.4°N and longitudes 88.7°E and 92.2°E. It covers an area of 38,394 square kilometres roughly measuring 140 km north to the South and 275 km East to West.

 It is estimated that over 72% of the land is under the vegetative cover with altitude varying from 100 m above mean sea level (msl) in the southern sub-tropical region to 7550 msl in the Northern Alpine region. Bhutan receives a fair amount of annual rainfall varying from 500 mm in the North to 5000 mm in the South. 

Thus, Bhutan is endowed with rich potential for harnessing hydro-power. Most of the schemes identified are run-of-the-river types and they are found to be techno-economically sound with least-cost and environment-friendly. Few reservoir schemes are also identified with limited and/or no environmental impact in the Southern belt before the Bhutanese rivers fan out and enter the Indian plains. 

Bhutan has an estimated hydro potential of 30,000 MW and 120 TWh mean annual energy generation indicating an average development potential of 781 kW in a square kilometre of land area.

So far 23,760 MW has been identified and assessed to be technically feasible. Only about 5 % of the potential is harnessed so far. The electricity sector’s share of the GDP has risen to about 20% and is the single largest contributor to the economy.

The development of several more mega hydropower projects over the current and future plan periods is likely to see an even greater prominence of the electricity sector within the national economy.

Bhutan’s ability to harness the hydro-power resources has been made possible because of the close and friendly ties with its neighbour, India. India has been the leading partner in providing both technical and financial assistance towards developing the vast hydro-power potential of Bhutan.

The relationship developed in the Hydropower sector has been a win-win situation for both countries as India has a power shortage while Bhutan has a large hydropower potential.  Hydroelectricity export has become the single most important source of revenue for Bhutan.

The Bhutanese economy saw estimated GDP growth of 8.5% in 2006-2007, an increase from 7.1% in 2005-2006. According to the annual report published by Royal Monetary Authority (RMA) the increase in GDP was driven by the commissioning of the Tala Hydro-Electric Project (1020 MW). Moreover, the growth is largely spurred by the sale of electricity to India from the power projects. The sale of Electricity constitutes about 80% of the total exports of Bhutan. 

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What is the hydroelectric power generation status of Bhutan?

 The tenth and Eleventh Five Year Plans for hydroelectric generating plants which are implementing by the Kingdom of Bhutan is listed in the table given below: 

Sl. No.	Project Name	Installed Capacity in MW	Construction Perion
01	Punatsangchu I HEP	1200	2008-2015
02	Mangdechu HEP	720	2009-2016
03	Punatsangchu-II HEP	1000	2009-2016
04	Bunakha Reservoir	180	2010-2016
05	Wangchu HEP	900	2010-2017
06	Chamkarchu-I HEP	670	2011-2017
07	KholongchuHEP	600	2012-2018
08	Amochu Reservoir	620	2012-2018
09	Kuri-Gongri HEP	1800	2012-2019
10	Sunkosh Reservoir	4000	20111-2020
	Total	11690	2008-2020

Hydro Power is the backbone of the Bhutanese economy. The rugged terrain, compounded by the fact that the Country is landlocked does not provide much economic advantage to Bhutan.

Transportation costs are high and unless Bhutan can think of certain niche products, her exports are not going to be competitive. The decision by the Royal Government to exploit its water resources for the production of electricity has changed the economic scenario for Bhutan. The rapid attitudinal variations with swift-flowing rivers have made Bhutan the natural haven for hydropower production.

The close and friendly ties between Bhutan and India have provided the necessary political will and the market for Bhutan’s power, as India has a huge power deficit. While electricity has provided the much-needed revenue, the Royal Government has also prioritized network expansion in the Country.

 It is expected that by 2020, the entire country will have access to electricity. Industrial activities are on the increase with the commissioning of the Tala Hydroelectric Project (1020 MW) in the year 2006. There is, however, a need to ensure that internal electricity tariff is kept affordable, so that, it becomes the main source of energy in the country and also to stimulate industrial activities.

 

Water is a natural resource that is in great abundance in Bhutan and the mountainous topography and climatic characteristics have endowed the country with a vast hydro-power potential of around 30,000 MW. Of this 23,760 MW is technically feasible which translates into a mean annual energy production capability of around 120,000 GWh.

This tremendous comparative advantage for the country has been tapped effectively through a mutually beneficial and highly successful partnership with the Government of India resulting in a win-win situation for both countries. India has generously provided valuable financial and technical resources to undertake the implementation of these complex and mega projects in addition to assuring the purchase of any surplus power generated.

The availability of reliable electricity also serves India’s growing needs for cheap power to continue growing rapidly and ensure its energy security. For Bhutan, the effective and sustainable utilization of its water resources has proved to be the key strategic success factor in furthering its sustainable development goals.

The harnessing of the country’s hydro-power potential closely parallels the rapid pace of socio-economic development and progress in Bhutan and has largely underpinned the strong economic growth and generated valuable resources to pay for a significant part of its social and other development investments.

At the start of the new millennium in 2000, hydro-power generation capacity in Bhutan stood at around 353.65 MW. By 2007 it had quadrupled to 1,489 MW. This capacity is further expected to be increased to 1,602 MW by the end of Bhutan’s Tenth Five Year Plan (2007-2012) and possibly reach 10,000 MW by 2020. The expansion of hydropower production capacity has had an enormous impact as by the end of the Ninth Five Year Plan, the energy sector contributed to around a quarter of GDP and 60% of national revenues.

This also excludes the major contribution that hydro-power infrastructure development makes to the construction sector, which accounts for another quarter of GDP. With a further doubling of capacity envisaged by the end of the 11 the Five Year Plan in 2017 or by the year 2020, the energy sector will probably contribute close to half of GDP and account for around three-fourths of the total national revenues.

The energy sector is thus strongly poised to continue leading and boosting growth in the future economic scenario and will greatly enhance the prospects of promoting higher living standards and reducing poverty levels in the country.

These projections are realistically based on and anchored by the Indo-Bhutan agreement on the long term cooperation in the field of hydro-power development signed by the two governments in July 2006. Under this umbrella agreement that is valid for sixty years, India will import a minimum of 5,000 MW of electricity from Bhutan by 2020.

Taking into consideration domestic consumption, the country needs to develop a hydro-power capacity of around 10,000 MW which would require the capacity addition of another 8,500 MW. With this capacity addition, it is envisaged that the country will have tapped around 42% of its technically feasible hydropower resources by 2020.

Just using the natural facilities hydroelectric power generation seamless geo-support that may make the Himalayan Kingdom of Bhutan a giant green electricity exporter of the Asian continent.