Why Capacitor and Capacitance are Used Electrical and Electronic Circuit?

The Purpose of Capacitors Using in Electrical Circuit.


Capacitor is an electrical or electronic device that used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator is known as capacitor.

How Many Types of Capacitor Possible?
Fig- Different Types of Capacitor
Simply we can define, single or multiple conductors or metallic parts when placed in parallel then it form a capacitor.


The effect or action of capacitance, or the behavior of capacitance is known as capacitance.

By definition of capacitance we can say, a capacitor is a passive two-terminal electronic component that stores electrical energy in an electric field and the effect of a capacitor is known as capacitance. 

The basic formula to calculate the capacitance of parallel plate capacitor is as below:

Equation of Parallel Plate Capacitance Measurement

What is Different Types of Capacitors & Their Characteristics?

The most common kinds of capacitors as per named using dielectric materials and/or anode or cathode are: 

Ceramic capacitors have a ceramic dielectric; Film and paper capacitors are named for their dielectrics; Aluminum, tantalum and niobium electrolytic capacitors are named after the material used as the anode and the construction of the cathode (electrolyte).

Ceramic capacitor:
Ceramic CapacitorThe Ceramic Capacitor is named as uses a ceramic material as the dielectric for capacitor which is a fixed-value capacitor where the ceramic material acts as the dielectric.. In Electronic Engineering, the Ceramic capacitors are the most widely used capacitors in the electronic circuits. These capacitors are mainly used where Ceramics were one of the first materials to be used in the proudhon of capacitors.

Electrolytic capacitor: 

Electrolytic capacitor
An electrolytic capacitor is a type of capacitor that uses an electrolyte to achieve a larger capacitance than other capacitor types. An electrolyte is a liquid or gel containing a high concentration of ions. 

An electrolytic capacitor in short named e-cap which is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor.

Metallized film Capacitor

Metallized film Capacitor: 

Metallized plastic film capacitors come in a variety of forms, using different materials. They are useful in many applications, especially as leaded components. Film capacitors are those kind of capacitors which use a thin plastic film as the dielectric. This film is especially made extremely thin using a sophisticated film drawing process.

Axial Leaded Film foil Capacitor: 

Film foil Capacitor

Type WPP axial-leaded, polypropylene flm/foil capacitors incorporate non-inductive extended foil construction with epoxy end seals. Type WPP is rated for continuous-duty operation over the temperature range of –55 ºC to 105 ºC without voltage derating. Low ESR, low dissipation factor and the inherent stability make Type WPP ideal for tight tolerance, pulse and high frequency applications. 


Tantalum Capacitor:

Tantalum Capacitor

A tantalum electrolytic capacitor is an electrolytic capacitor, a passive component of electronic circuits. It consists of a pellet of tantalum metal as an anode, covered by an insulating oxide layer that forms the dielectric, surrounded by liquid or solid electrolyte as a cathode.

Silver Mica Capacitor:

Silver Mica Capacitor

The silver mica capacitor provides close tolerance values with low levels of value change with temperature. Silver mica capacitors are high precision, stable and reliable capacitors

The silver mica capacitor provides close tolerance values with low levels of value change with temperature and are available in small values, and are mostly used at high frequencies

Super-capacitors or in short SuparCap is made with graphene as the conducting plate are capable of storing a charge similar to lithium-ion batteries.

Amazing Facts About Capacitor and Capacitance

  1. A capacitor is an electrical or electronic circuit component that made of two conducting plates separated by a dielectric or non-conducting insulator material;
  2. Capacitor shapes are fixed, either flat or cylinder;
  3. The Leyden jar was the first capacitor created, invented in 1745 by Pieter van Musschenbroek;
  4. The characteristics of a capacitor is also known as capacitance measured in unit farad;
  5. A capacitor’s conducting surfaces are made of a thin film of conductive metal or aluminum foil;
  6. The positively charged plate is known as the anode and the negatively charged plate is known as the cathode;
  7. To get higher capacitance values dielectric materials should be higher dielectric constant;
  8. The example of dielectric materials used in capacitors are ceramic, air, vacuum, paper impregnated with oil or wax, mylar, polystyrene, mica, glass etc.;
  9. When a capacitor is connected to a power source, positive charges transfer to one of the conducting surfaces, and negative charges are transferred to the other conducting surface;
  10. Normally a capacitor can absorb energy from a circuit and store it temporarily and then return the energy to the circuit;
  11. Capacitor can store the energy for long time that used as data memory circuit in computer technology;
  12. Capacitors discharge very slowly, but many can store a charge for years;
  13. Handling a larger size charged capacitor in the wrong way can result in burns or even death;
  14. A capacitor is discharged slowly when a resistor is connected to each leg of capacitor;
  15. Capacitors are measured in a unit named farad after the scientist Michael Faraday; 
  16. Super-capacitors made with graphene as the conducting plate are capable of storing a charge similar to lithium-ion batteries.

What is the Largest Capacitor in the World?

The Sunvault Energ company collaboration with Edison Power is developing graphene-based super-capacitor technology for use in solar cell arrays. In November 2015 Sunvault announced that announced the creation of the world's largest 10,000 Farad Graphene Supercapacitor. The companies declared that this development is the most significant breakthrough in the development of Graphene Super-capacitors till to date. 

Capacitor Formula:

The formula of capacitor means the total capacitance of a capacitor measured by it's place area and current relations that defined early.
Now, we will find the resultant capacitance when multiple capacitor connect in series or parallel:

Capacitor in Parallel Parallel Capacitor Connection

Capacitor in Series
Capacitor in Series Connection

What is a Capacitor Used for? How is a Capacitor Used in a Motor Circuit?

A run capacitors primary function is to bring the start winding in phase with the run winding. It also adds 30-40 percent more starting torque. But the starting torque is its secondary purpose. Also, the voltage rating of the capacitor- 370 or 440, is the amount of cemf,(counter electromotive force) produced by the windings, magnets, armature, etc of the motor, that the capacitor can handle. 

If a motor produces a back voltage over 370, you must use a 440 rated capacitor. If not, the capacitor will fail. Phase problems occur when a capacitor is either weak or too large for the motor. If a  motor calls for a 7.5 mfd capacitor and the capacitor is weak, the motor will often still start but the capacitor will not be able to bring the star.

Capacitor Working Principle

The capacitance depends on the geometry of the conductors and nature of the medium. A capacitor is a device for storing electric charges. 
Capacitor Working Principle

Consider an insulated conductor (Plate A) with a positive charge ‘q’ having potential V (Fig-a). The capacitance of A is C = q/V.

When another insulated metal plate B is brought near A, negative charges are induced on the side of B near A. An equal amount of positive charge is induced on the other side of B (Fig-b). 

The negative charge in B decreases the potential of A. The positive charge in B increases the potential of A. But the negative charge on B is nearer to A than the positive charge on B. So the net effect is that, the potential of A decreases. Thus the capacitance of A is 

If the plate B is earthed, positive charges get neutralized (Fig-c). Then the potential of A decreases further. 

Thus the capacitance of A is considerably increased. The capacitance depends on the geometry of the conductors and nature of the medium. A capacitor is a device for storing electric charges.

Smart Grid Technology and Application

Smart Grid
Fig-Transformer Connection

What is Smart Grid Technology?

A smart grid is an electricity network which includes a variety of equipped and energy measures including smart meters, smart appliances, renewable energy resources, and energy efficiency resources based on digital technology that is used to supply electricity to consumers via two-way digital communication. The term smart-Grid also known as digital-grid that refers to the new digital technology or to modernize the electrical network grid.

How Smart Grid Uses in Electricity Network System?

The expression Smart-grid usually refers to a category of technology folk’s square measure exploitation to bring utility electricity delivery systems into the twenty first century, exploitation computer-based device and automation. 

These systems square measure created potential by two-way communication technology and PC process that has been used for many years in alternative industries. 

They’re getting down to be used on electricity networks, from the facility plants and wind farms all the thanks to the shoppers of electricity in homes and businesses. 

They provide several advantages to utilities and shoppers -principally seen in huge enhancements in energy potency on the electricity grid and within the energy users’ homes and offices.
For a century, utility firms have had to send employees bent on gather a lot of the info required to produce electricity. 

The employees browse meters, explore for broken instrumentality and live voltage, as an example. 

Most of the devices utilities use to deliver electricity have however to be machine-driven and computerized. Now, several choices and product square measure being created out there to the electricity business to modernize it.

Smart Technology Association to Smart Grid

The grid amounts to the networks that carry electricity from the plants wherever it's generated to shoppers. The grid includes cables, substation-equipment like- transformers, switches, control system and so on.

Much within the approach that smart- phones are recently suggests that a phone with a PC in it, good grid suggests that computerizing the electrical utility grid. It includes adding two-way electronic communication technology to devices related to the grid. 

Every device on the network are often given sensors to collect knowledge (power meters, voltage sensors, fault detectors, etc.), and two-way electronic communication between the device within the field and also the utility’s network operations center. 

A key feature of the good grid is automation technology that lets the utility change and management every individual device or variant devices from a central location.
The number of applications which will be used on the good grid once the info engineering is deployed is growing as quick as creative firms can produce and turn out them. 

Advantages embrace increased cyber-security, handling sources of electricity like wind and alternative energy and even integration electric vehicles onto the grid. 

The businesses creating good grid technology or providing such services embrace technology giants, established communication companies and even greenhorn technology companies.

Smart Grid System in Bangladesh

As a modern concept smart grid which refers mainstream power transmission network system solution in Bangladesh, transmission system engineers should be acquainted with the knowledge of Smart transmission or smart grid System.

In its national leadership role, Power Grid may have partnered with key stakeholders from business, academia, and state governments to modernize the nation’s electricity delivery system. Power Grid and its partners determine analysis and development (R&D) priorities that address challenges and accelerate transformation to a better grid, supporting demonstration of not solely good grid technologies however additionally new business models, policies, and social group advantages. Power Grid has incontestable leadership in advancing this transformation through cooperative efforts with energy regulatory authority on good Grid.

Aligning Stakeholders to Achieve Smart Grid Network

In leading a national transformation to a better grid, Power Grid may begin to outline not solely a vision for the long run electrical delivery system however additionally the practical characteristics. 

Power Grid take initiative to form a practicum involving regulators, utilities, vendors, legislators, analysis establishments, universities, and alternative stakeholders to forge a standard vision and scope for the good grid. 

This biennial effort must result in identification of the principal good grid practical characteristics that comprise the muse of Power Grid’s good grid program.

As outlined by the principal characteristics, Power Grid can encompass a vision of a wise grid that uses digital technology to boost reliability, resiliency, flexibility, and potency (both economic and energy) of the electrical distribution system. The strategy to realize this vision hinges upon activities that directly address the technical, business, and institutional challenges to realizing a better grid.

Smart grid demonstrations and preparation activities cash in of the chemical action impact of considerable investments within the producing, getting and installation of devices and systems. 

These activities leverage efforts below approach within the analysis and development activity space and can facilitate develop important performance and proof-of-concept knowledge. 

This activity space is additionally developing a framework for analyzing good grid metrics and advantages, which are important to assist, build the business case for cost-efficient good grid technologies.
Research and development activities advance good grid practicality by developing innovative, next-generation technologies and tools within the areas of transmission, distribution, energy storage, power physics, and cyber security and also the advancement of precise time-synchronized measures of sure parameters of the electrical grid.
Interoperability and Standards activities make sure that new devices can interoperate in very secure surroundings as innovative digital technologies square measure enforced throughout the electricity delivery system, advancing the economic and energy security of us. 

The continuing good grid ability method guarantees to steer to versatile, uniform, and technology-neutral standards that modify innovation, improve client selection, and yield economies of scale. 

Ability and standards activities don't seem to be restricted to technical info standards; they need to be advanced in conjunction with business processes, markets and also the restrictive surroundings.
Interconnection coming up with and analysis activities produce larger certainty with relation to future generation, as well as characteristic transmission necessities below a broad vary of other electricity futures (e.g., intensive application of demand-side technologies) and developing semi permanent interconnection-wide transmission growth plans.
Monitoring national progress activities establish metrics to point out progress with relation to overcoming challenges and achieving good grid characteristics. 


High Voltage Power Transmission Tower

Transmission and Distribution of Electrical Power Efficient and Smartly.

Considering the main parts of a typical Transmission & Distribution network, here are the average values of power losses at the different steps:

1-2% – Step-up transformer from generator to Transmission line

2-4% – Transmission line
1-2% – Step-down transformer from Transmission line to Distribution network
4-6% – Distribution network transformers and cables

The overall losses between the power plant and consumers is then in the range between 8 and 15%.

Except some isolated individual normal generation, most of national grid electricity is not used in the same place where it is generated. Meaning is that some individual normal scale generator may produce electricity for industrial, commercial or residential purposes where it used; but mass scale produced electricity actually generates far distance from consumer or city center.   Sense is that long-distance electrical transmission and distribution systems are necessary; that is ours topic today Transmission and Distribution of Electrical Power Efficient and Smartly.

There are many obligations, advantages and disadvantages of electrical power generation, transmission and distribution from distance to consumer end; but todays focus only energy losses due to transmitting electricity over distance via networks. Electrical energy losses are very well known to us as system loss.

There is a myth here in Bangladesh, system losses means it is causes of some dishonest employees of the utility company. Fact is that without system losses electrical network is not possible ever. Following efficient and smart electrical energy transmission and distribution system this losses may keep in economic level, not in zero level.

In presence of high electrical power demand compare to less power generation in Bangladesh we need to minimize this loss to achieve the main goals: Reduce resource consumption while delivering more power to users. Reducing consumption can be done in at least two ways: deliver electrical energy more efficient and smartly and change consumer habits.

Transmitting electrical energy from generating station to user’s end through electrical transmission and distribution network require power cable, power transformer, operating and protective equipments which create three types of energy loss:

Energy is lost as heat in copper or aluminium conductor, causes joule effect;

Energy dissipates into a magnetic field which is magnetic loss;

Energy is absorbed in insulating materials, causes of dielectric effect.

Above-mentioned causes for loss of electricity is totally technical, expert and engineers only can control this type of losses. Others way electricity user also can control the loss and reduce their consumption just changing their habits.

Changing consumer habits needs smart awareness-raising programmes, taking undertaken by governments or activist groups over and over again. Simple things, such as turning off lights in unoccupied rooms, or switching off the television/electronic devices at night (not just putting standby mode), use water pump/ laundry at non-peak hour, or setting the air-conditioner temperature at 25oC.

Technology is changing and improving day by day, of course also for electrical energy transmitting system. More efficient and smart conductors, transformers and equipments are building for energy transmission and distribution network. High efficiency transformers, superconducting transformers, high temperature superconductor are new smart and efficient technologies in this side.

Just getting idea, conductor losses about 2.5% to 3%, transformer and equipment losses about 1% to 2%. Imagine what is our benefit if 1% energy is saved or loss is reduced; say our electricity generation is 10,000 mega watts. 1% loss means 100 mega watts that can electrify more 20,000 houses, in rural area it may be 100,000 houses. So, you electricity user can efficient and smart your electrical power transmission and distribution of system and light up more houses just switching off your un-occupied rooms. 

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How Can Convert Single Phase Power Into Three Phase?

You may find there three options to convert the single phase power convert into three phase, such as-

  1. static converter- using capacitor to create a power waveform;
  2. rotary converter- using connect single-phase motor to three-phase generator; 
  3. electronic converter- using single-phase power converting into DC and then inverting into three-phase AC.

Converting Single Phase Power Into Three Phase: Using Digital Converter

Here in this article we will discuss and try to give very basic idea about converting the single phase power into three phase power in different practicable way. This is not the detail circuit diagram or shop design. This is the conceptual drawing that will help a beginner to start their project or enlarge their thinking about critical power supply.
Digital Phase Converter from Single Phase to Three Phase
Convert Single Phase Into Three Phase
 A digital phase converter actually creates a three phase from a single phase power  using a digital signal processor (DSP) or a electronic circuit what is used to control power electronic devices to generate a third phase of voltage.

This type of phase converter is much more balanced and stable system, so far using a two to three phase converter.

Principle of Digital Single to Three Phase Converter:

The digital phase converter actually convert the  AC power from the utility to DC, then back to AC. The power switching devices Insulated Gate Bipolar Transistors (IGBT) is uses to process.

"The Insulated Gate Bipolar Transistor also called an IGBT for short, is something of a cross between a conventional Bipolar Junction Transistor, (BJT) and a Field Effect Transistor, (MOSFET) making it ideal as a semiconductor switching device".

In converter circuit, IGBTs in series with inductors are used in series with the input rectifier circuit where IGBTs are controlled by pre-programmed software in DSP to draw the sinusoidal current from the single-phase line charging capacitors on a constant DC voltage. Also the controlled rectifier input allows power factor correction.

The Power drawn from output of IGBTs are not sinusoidal AC voltage.
It is actually very high harmonic distorted  pulse-width modulated (PWM) waveform, when this passes through an inductor/capacitor filter circuit then output become conventional a sine wave voltage.

Converting Single Phase Power Into Three Phase: Using Three Phase Motor

It can make a Rotary Phase Converter using a three phase motor started up in Single Phase with the spare leg connected to Capacitors to cause a phase shift to make the motor start up and run.

Using the following connection procedure a single phase motor can drive a three phase generator, means it convert a single phase source into a three phase power source.

Advantages and Disadvantages of Different Converters 

Considering the above mentioned three types of converters we can conclude that static converters have lots of problems, and are generally a seriously inferior solution, but they are cheaper and do work in some situations. On the other way moderately but cleanest three-phase power generator is the rotary converters, but  they have moving parts. Finally the  electronic converters are also fairly expensive but have no moving parts.


Outdoor Steel Structure for 132kV HV Power Cable
Fig-A Typical Outdoor Grid Substation

Outdoor Steel Structure Design and Installation for HV & EHV Power Cable

The structures shall be designed to carry cable sealing ends, cables and cleats, earthing bars, earth disconnecting links, sunshields and other fittings  should be followed an adequate design manner.

Each sealing end should be provide with a separate structure which be positioned so as to align with the phase center distances of the substation equipment but not less than the minimum electrical and safety clearness as international standard like specified in BS 162.

All structures should be equipped with a suitable framework mounted immediately below the sealing ends to accommodate a phase plate in a conspicuous position. All phase plates shall be manufactured from mild steel sheet with vitreous enameled finish.

Don’t compromise to provide for fixing and bonding copper fittings as may be necessary to accommodate all apparatus affixed thereto and to secure the structures to their foundations.

Factors of Safety on Outdoor Structure for 132kV Power Cable

The factor of safety for each complete structure and foundation should not be less than 2.0, based upon the maximum working loadings specified and described below.

In calculations of the factor of safety the strength of compression members should be based on the crippling loads as International Standard formula.

The strength of both tension and compression members should be based on the elastic limit and the rate of unsupported length to their least radius of gyration should not be more than:
120 - for main members
200 - for braces
250 - for redundant members
350 - for members loaded in tension only

Maximum Simultaneous Working Loads on Outdoor Structure

The assumed maximum simultaneous working loads on the structures should be reckoned as follows:

Wind Loading of Structure

i) A wind pressure of 1427 N/m2 applied at right angles to the lines on the whole projected areas of phase conductors of 1686 n/m2 in the case of earth wires. A wind pressure of 1427 N/m2 shall also be applied to the projected area of each insulator set.

ii) A wind pressure of 4280 N/m2 on the whole projected area of any one face of the structure.

Vertical Loading on Structure

Vertical loadings should include dead weight of all conductors insulator and equipment and the self weight of the structure. 

All structures also should be capable of supporting a loading of 150 kg per phase to allow for imposed loads of men and tools during maintenance however this loading is not to be combined with other loadings in checking the overall factor of safety.


Design of Outdoor Steel Structure for 132 kV Power Cable Installation

132kV Power Cable Outdoor Steel Structure Design
Fig-CAD drawing for steel structure
The compression members shall consist of rolled steel sections and the tension members of rolled steel sections or flats. The design shall be such as to keep the number of different parts as small as 

Pockets or depressions likely to hold water shall be avoided and if not avoidable shall be properly drained.

Steel structures should be fabricated from either mild steel BS4360 grade 43A or high tensile steel BS 4360 part 2 grade 50C. Notable that all material should be free from blisters, scale or other defects.

All members should be stamped or marked for erection purposes.
All members, fittings, bolts, washers, screwed rods, nuts etc., should be galvanized.

All parts shall be secured by means of bolts and nuts and screwed rods whose minimum diameter shall be 12.5 mm. All nuts and pins shall be locked in position by means of lock washers or other approved devices. Taper washers should be provided where necessary.

When in position, all bolts or screwed rods shall project through the corresponding nuts but by no more than 10 mm. Bolt heads rather than nuts shall be on the outer faces of members.

No bolts hole shall be more than 1.5 mm larger than the diameter of the bolt, but after galvanizing sufficient clearance shall be left for insertion of the bolts.

During erection care shall be taken to ensure that the structures are not strained or damaged in any way and that the treated surfaces are not injured. Rust streaks and foreign matter deposited on galvanized surfaces during transport and storage shall be removed.

Workmanship of Steel Structure

All members shall be cut to jig and all holes shall be drilled or punched to jig so that when the members are in position the holes will be truly opposite each other before being bolted up. Drifting or reaming of holes will not be allowed.

The drilling, punching, cutting and bending of all steelwork and the removal of sharp edges and burrs shall take place before galvanizing.

Approved steel gauges of the stud type shall be provided to enable checking of members as may be considered necessary by the qualified Engineer.

Built members shall when finished be true and free from al kinks, twists and open joints and the material shall not be defective or strained in any way.

In order to check the workmanship, not less than 1% of the members corresponding to each type of support shall if required be selected at random and assembled to form complete supports in the presence of the qualified Engineer at the manufacture’s works.


Sun-shields on Structure for Power Cables

At places where power cables are brought above ground level e.g. sealing end structures, proper sun shields shall be provided and fitted. These shall comprise of perforated cable trays galvanized and fitted externally to each. Sealing end structure such as to shield the cable from sunlight and allow air flow over the cable.

Marking on Steel Structure Sections

All steel sections, fish-plates and gusset plates should be indelibly marked with an assembly code number or letter, or a combination of both, to facilitate quick recognition and correct assembly. If this identification is stamped on to the member, it’s may  applied before galvanizing.

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

Hydro-power generation plant schematic diagram
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 also one of the most cheap electrical energy production method.

Limitation of hydroelectric energy generation mostly depends on natural geographical location that Bhutan can meets naturally. Topographic facilities to generate hydroelectric energy may change the Bhutan’s economical position, just exporting the surplus electricity to neighbors’ 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 origin 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 hydro-power 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.


What makes Bhutan as 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 it’s origin in Chumbi valley of Tibet and flows through western districts of Haa and Samtse before draining into 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 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 catchment of the 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 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 feature:

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

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

What is Exceptional Hydroelectric friendly geo-location of Bhutan?

Hyro-power generation natural dam
Fig-2: A Perfect Water Reaserver 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 land mass with good vegetation cover, 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 kilometers 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 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 environment 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 kilometer 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. 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 hydro-power 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 neighbor, 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 Hydro power sector has been a win-win situation for both the countries as India has a power shortage while Bhutan has a large hydro power potential.  Hydroelectricity export has become the single most important source of revenue for Bhutan.

The Bhutanese economy saw an 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 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. Sale of Electricity constitutes about 80% of the total exports of Bhutan. 


What is the hydroelectric power generation status of Bhutan?

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

Sl. No.
Project Name
Installed Capacity in MW
Construction Perion
Punatsangchu I HEP
Mangdechu HEP
Punatsangchu-II HEP
Bunakha Reservoir
Wangchu HEP
Chamkarchu-I HEP
Amochu Reservoir
Kuri-Gongri HEP
Sunkosh Reservoir


Hydro Power is the backbone of the Bhutanese economy. The rugged terrain, compounded by the fact that the Country is land locked 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 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 hydro power 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 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 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 socioeconomic 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 the Bhutan’s Tenth Five Year Plan (2007-2012) and possibly reach 10,000 MW by 2020. The expansion of hydro-power 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 th 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 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 hydro-power resources by 2020.

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