Hydro Power an Introduction

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Presented by

Raghubir S. Rawat

Hydropower: An Introduction

Presented B y : Raghubir S.Rawat


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IntroductionEnergy E = mghthe power is related to the mass flow rate .

Substituting with P and Q andintroducing , for efficiency weget

Power, P = g Q H

P = 0.008829QH MW

Note: cumec = one m3/s & cusec =one ft3/s.

Where = density ofwater, 1000 Kg/m3g = gravitationalacceleration, 9.81m/s2Q = flow rate, m3/sH = Head of fall whichis utilized, m = overall efficiency

(say 90 %)


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Overview

The hydropower industry is closely linked to both water management andrenewable energy.

Production and thus has an important role, in cooperation with the internationalcommunity, and

In striving for sustainable development in a world where billions of people still lackaccess to safe drinking water and adequate energy supplies.

"The problem, though, is not the dams. It is the hunger. It is thethirst. It is the darkness of a township. It is township and rural hutswithout running water, lights or sanitation. It is the time wasted ingathering water by hand. There is a real pressing need for power in

every sense of the word.

Nelson Mandela [WCD Launch, 16 November 2000, London]


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Distribution Of Electricity

Supply


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Overview Hydropower is renewable because it draws its essential energy from the sun which drives the

hydrological cycle which, in turn, provides a continuous renewable supply of water.

Hydropower represents more than 92 percent of all renewable energy generated, and continues tostand as one of the most viable sources of new generation into the future. It also provides an option tostore energy, to optimize electricity generation.

The International Hydropower Association (IHA), the Implementing Agreement on HydropowerTechnologies and Programmes of the International Energy Agency (IEA/Hydro), the Canadian

Hydropower Association (CHA) and the International Commission Large Dams (ICOLD), are world-wideorganisations that are proponents of responsible hydropower development

By the year 2050, the world population is expected to increase by 50 per cent, from 6 to 9 billion .

Energyonsumption per inhabitant per year is generally in correlation with the standard of living of thepopulation, which is characteristic of welfare from an economic, social and cultural point of view. Todaythe less developed countries in the world, with 2.2 billion inhabitants, have an annual per capita

consumption of primary energy which is 20 times less than those of the industrialised countries (with1.3 billion inhabitants), and per capita electricity consumption which is 35 times less.

In view of this situation, all available sources of energy will be necessary, but for environmentalreasons, the first priority should be the development of all the technically, economically andenvironmentally feasible potential from clean, renewable energy sources, such as hydropower.


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Why Hydopower ?High Reliability:Hydropower is a proven, well understood technology based on more than a century of

experience. Its schemes have the lowest operating costs and longest plant lives.

High Efficiency:Hydropower plants provide the most efficient energy conversion process. Modern plants can

convert more than 95 per cent of moving waters energy into electricity, while the bestfossil-fuel plants are only about 60 per cent efficient. Hydropower also has the highestenergy payback ratio. During the lifetime of a scheme, it can produce more than 200times the energy needed to build it.

High Flexibility:Hydropower schemes with adequate storage reservoirs offer the capacity to meet

instantaneous fluctuations in demand. These technical advantages are part of an array ofbenefits known as ancillary services, which enable hydropower to optimize the use ofother electricity sources.

Building the backbone of an integrated renewable gridHydropower can provide the required back-up energy to sustain other renewable energy

sources with intermittent services, to ensure electricity supply at times when there is nowind or sun.

Increasing the efficiency of mixed systemsAlthough hydropower resources are not evenly distributed, or sufficient in total to meet the

worlds demand for electricity, hydro can play an important role in reducing the

disadvantages of thermal power generation. Well-managed peaking and pumped-storageschemes integrated into a mixed system will reduce atmospheric emissions and optimizethe efficiency of the total power system.


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Energy TechnologiesAnd Their CurrentGenerating Costs

(adapted from UNDP 2000.World Energy Assessment,

pp. 15, 281, 282, 292, 386)


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Advantages AndDisadvantages Of

Hydro Power Projects


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wTheir Greenhouse Gas

Emissions


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Major Hydro-power Projects In India


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Power Scenario In India Economically exploitable hydro potential is 84044 MW at 60% load

factor to.

Hydroelectric Schemes in operation account for only 14.84 %

Hydroelectric Schemes under execution account for only 6.99 % oftotal potential.

Bulk of potential 78.17 % remains to be developed. Small hydro accounts for 6781.81 MW under 1512 scheme

Maximum Hydro-power potential in Arunachal Pradesh is 26756 MW(Installed capacity 60,000 MW)

Second highest in hydro power potential is Himachal Pradesh 11747MW(Installed capacity of 25000 MW)


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Types Of Hydropower

Reservoir or impoundment type

Run of the river scheme.

Plumped storage plant.

Tidal


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Impoundment TypeUses a dam to store water. Water may be

released either to meet changing electricityneeds or to maintain a constant water level.

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KYANVILLAGE

Project

View point

DAM

CREAST

Diversion

Tunnels

PowerHouse

MAIN

DAM

Penstocks

De-siltin

g

Cham

ber

Spillw

ay

Switchyard

o amo am ro ecro ecLayoutLayout


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umpe oragePlant

Pumped storage hydroelectricity is a type of hydroelectricpower generation used by some power plants for loadbalancing. The method stores energy in the form of water,pumped from a lower elevation reservoir to a higher elevation.

Low-cost off-peak electric power is used to run the pumps.During periods of high electrical demand, the stored water isreleased through turbines.

Although the losses of the pumping process makes the plant anet consumer of energyoverall, the system increasesrevenue by selling more electricity during periods of peakdemand, when electricity prices are highest.

At times of low electrical demand, excess generation capacity is used to pump water intothe higher reservoir. When there is higher demand, water is released back into the lowerreservoir through a turbine, generating electricity. Reversible turbine/generator assembliesact as pump and turbine (usually a Francis turbine design).

Pure pumped-storage plants just shift the water between reservoirs, but combined pump-

storage plants also generate their own electricity like conventional hydroelectric plantsthrough natural stream-flow


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Pumped Storage Plant Taking into account evaporation losses from

the exposed water surface and conversionlosses, approximately 70&percnt; to85&percnt; of the electrical energy used topump the water into the elevated reservoircan be regained.

The technique is currently the most cost-effective means of storing large amounts ofelectrical energy on an operating basis, butcapital costs and the presence of appropriategeography are critical decision factor

Along with energy management, pumpedstorage systems help control electrical

network frequency and provide reservegeneration.

Thermal plants are much less able to respondto sudden changes in electrical demand,potentially causing frequency and voltageinstability. Pumped storage plants, like otherhydroelectric plants, can respond to loadchanges within seconds.


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Pumped Storage Plant

Along with energy management,pumped storage systems help controlelectrical network frequency andprovide reserve generation.

Thermal plants are much less able torespond to sudden changes in electricaldemand, potentially causing frequencyand voltage instability. Pumped storageplants, like other hydroelectric plants,can respond to load changes withinseconds.

E.g Tehri Dam, Uttranchal , 1,000 MW


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Pumped StoragePlant

Pumped-storage facilities have some distinctivefeatures:

Greater output can be obtained with smallerreservoirs in comparison with conventionalhydropower.

They use the water stored in the reservoirsrepeatedly and do not need large naturalinflow to the reservoirs.

While conventional hydropower can onlygenerate power, pumped storage can absorbpower when the system has an excess.

Pumped-storage plants work as a huge storagebattery by charging or discharging poweraccording to the systems demand.

During off-peak hours, such as the early morning

hours, excess electricity produced byconventional powerplants is used to pumpwater from lower to higher-level reservoirs.

During periods of highest demand, the water isreleased from the upper reservoir throughturbines to generate electricity.

The combined use of pumped storage facilitieswith other types of electricity generationcreates large cost savings through the moreefficient use of base-load plants.


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Dams Hydropower currently provides 19&percnt; of the world's total

electricity supply, and is used in over 150 countries with 24 ofthese countries depending on it for 90&percnt; of their supply.

30-40&percnt; of the 271 million hectares of agricultural landirrigated worldwide rely on dams.

60&percnt; of the world's 227 largest rivers are severelyfragmented by dams, diversions, and canals - leading to the

degradation of ecosystems.


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Dams : Facts And FiguresThe World Commission on Dams estimated that there are as many as 48,000

dams over 15m high worldwide. About half of these are in China. There are about4300 dams in India.

The International Commission on Large Dams (ICOLD) defines a large dam asbeing over 15 m high. The definition also includes dams between 5-15 m high

with a reservoir exceeding 3 million cubic meters.

Dam building peaked in the '70s and declined globally after that. Nevertheless,dam building in China, Turkey, Brazil and India still continues on a large scale.

On average one new dam is build every day and the average construction time is4 years.

Itaipu, shared between Brazil and Paraguay, has the highest installed capacity atthe moment, with 12,600 MW. When the Three Gorges Dam is completed it willtake over as the dam with the largest capacity, reaching 18,200 MW.

About 1500 dams are currently under construction worldwide.


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DAMS

Classification based on the building materialused.

Embankment Dams

Concrete dams: Types are as follows :

Gravity dams Arch dams

Buttress dams


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Embankment DamsICOLD defined an embankment dam as, "any dam constructed

of excavated materials placed without addition ofbinding materials other than those inherent in thenatural material. The materials are usually obtained ator near the dam site

Embankment dams are made from compacted earth, and havetwo main types, rock-fill and earth-fill dams.

Larger embankment dams are zoned and constructed of avariety of materials, either extracted from different localsources or prepared by mechanical or hydraulic separationof source material into fractions with different properties

An important element in a zoned dam is an impermeable blanket or core which

usually consists of clayey materials obtained locally.

An advantage compared with concrete dams is that the bearingstrength requirements of the foundation are much less.

e.g Tehri Dam , Kol Dam .


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Embankment DamsAn earth dam is basically a trapezoidal

embankment built in a valley to form awater reservoir. The design has to ensure:

1. It is impermeable enough to prevent excessive lossof water from the reservoir.

2. The design must ensure stable slopes.

3. Settlement of the dam must not be excessive so asto reduce the freeboard of the dam.

4. The upstream slope of the dam must be protectedfrom the destructive action of waves, and thedownstream slope must withstand rainfall erosion.

5. A sufficient bond between the embankment and itsfoundation must exist to prevent the developmentof seepage paths; excessive hydrostatic uplift mustbe controlled by proper drainage.


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Project


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Concrete Dams

Gravity Dams

In a gravity dam, stability is secured by making it of

such a size and shape that it will resist overturning,sliding and crushing at the toe.

This is the case if the resultant force of water pressureand weight falls within the base of the dam.

Gravity dams are classified as "solid" or "hollow." Thesolid form is the more widely used of the two,though the hollow dam is frequently moreeconomical to construct.

Coulee Dam is a solid gravity dam and Itaipu Dam is ahollow gravity dam.

The Eder dam inGermany, built around1910.


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Concrete Dams

Arch Dams

In the arch dam, stability is obtained by a combination ofarch and gravity action.

For this type of dam, firm reliable supports at theabutments (either buttress or canyon side wall) aremore important. The most desirable place for an archdam is a narrow canyon with steep side wallscomposed of sound rock.

A similar type is the double-curvature or thin-shell dam.E.g Idduki Dam and Hoover Dam. Hoover dam


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Concrete Dams

Buttress Dams

Buttress dams were first developed toconserve water in regions wherematerials were scarce or expensive butlabour was cheap. These Dams wereused for irrigation and mining purposes.


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Types Of Hydroelectric Projects:Respective Services And Main Impact

Sources


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Average Size Of Hydro Reservoir Per

Unit Of Capacity (Goodland,1995)


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Tidal power 'Tidal power, sometimes called Tidal energy, is a form of hydropower thatconverts the energy of tides into electricity or other useful forms of power.

Although not yet widely used, tidal power has potential for future electricitygeneration. Tides are more predictable than wind energy and solar power.Historically, tide mills have been used, both in Europe and on the Atlanticcoast of the USA. The earliest occurrences date from the Middle Ages, or evenfrom Roman times

Tidal energy is generated by the relative motion of the Earth, Sun and theMoon, which interact via gravitational forces. Periodic changes of water levels,and associated tidal currents, are due to the gravitational attraction by the Sunand Moon. The magnitude of the tide at a location is the result of the changingpositions of the Moon and Sun relative to the Earth, the effects of Earthrotation, and the local shape of the sea floor and coastlines.

Because the Earth's tides are caused by the tidal forces due to gravitationalinteraction with the Moon and Sun, and the Earth's rotation, tidal power ispractically inexhaustible and classified as a renewable energy source.

A tidal energy generator uses this phenomenon to generate energy. Thestronger the tide, either in water level height or tidal current velocities, thegreater the potential for tidal energy generation.


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ITAIPUDAM

total view of the ITAIPU power plant

Left part shows overflow (spillway), thepower station is located in the middle.


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ITAIPU DAM Location: The Parana River betweenBrazil and Paraguay.

The Parana river is the seventh largestin the world and had to be diverted to

construct the dam.

The installed generation capacity of theplant is 14 GW , with 20 generatingunits of 700 MW each. In the year 2008,it achieved its generating record of94.68 billion kilowatt-hours (kWh),which supplied 90% of the energy

consumed by Paraguay or 19% of thatconsumed by Brazil

In 1994, the American Society of CivilEngineers elected the Itaipu Dam asone of the Seven Wonders of theModern World

At the bottom of the 196 mtall damThe white tubes are containingthe inlets for the 18 turbines(715 MW each).


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ITAIPU DAM The amount of concrete used to build the Itaipu

Power Plant would be enough to build 210 footballstadiums.

The iron and steel used would allow for theconstruction of 380 Eiffel Towers.

Around forty thousand people worked in theconstruction

The water intake of one single 715 MW Francis-turbine is 700 m/s, its weighted efficiency is93.8%.

approximately 10,000 families living beside theParan River were dislodged from their plots in

order to make way for the dam

The final cost of ITAIPU amounts to US$ 20 billion,

If whole area of the lake - at nominal level - wouldbe covered by solar modules for the same yearlyoutput as ITAIPU a solar PV-plant would cost US$132 billion


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HOOVERDAM


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HOOVER DAM LAYOUT


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HOOVER DAMTo provide much morehighway capacity, andbetter safety, thenew Hoover Dam Bypass isscheduled to be completed

in 2010

It will divert the U.S. 93traffic 1,500 feetdownstream from the dam.

The bypass will include acomposite steeland concrete arch bridge,tentatively named the MikeO'Callaghan-Pat TillmanMemorial Bridge

HOOVER


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HOOVERDAM

Construction period: April 20,1931 March 1, 1936

Construction cost: $49 million($736 million adjusted

for inflation from 1936 to 2008)

Deaths attributed toconstruction: 112; 96 of themat the construction site.

Following an uprating projectfrom 1986 to 1993, the totalgross power rating for theplant, is about 2080 MW.


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HOOVER DAMHoover Dam, originally known

as Boulder Dam, is a concrete-gravity dam in the Black Canyon ofthe Colorado River, onthe border between the U.S. statesof Arizona and Nevada .

When completed in 1935, it was

both the world's largest electric-power generating station and theworld's largest concrete structure.

named after Herbert Hoover, who

played an instrumental role in itsconstruction, first as the Secretaryof Commerce and then later asthe President of the United States


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THREEGORGES

DAM


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THREE GORGES DAM

The Three Gorges Dam spans the Yangtze China.

With a length of more than 6,300 km and a naturalfall of 5,400 meters from the west to the east, theflood-prone Yangtze River is the largest of the kind inChina and the third largest in the world.

It is the largest hydro-electric power station in theworld.

Except for a planned ship lift, all the original plan ofthe project was completed on October 30, 2008,when the 26th generator was brought to commercialoperation.

Six additional generators in the underground powerplant are being installed, with the dam thus notexpected to become fully operational until about2011.

The total electric generating capacity of the dam willreach 22,500 MW.


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THREEGORGES DAM

The dam was first envisioned in 1919.[

Dam was approved by the National People'sCongress in 1992 with a record number ofabstentions and dissenting votes .

The construction started on December 14,

1994.

The dam was expected to be fullyoperational in 2009, but due to additionalprojects such as the underground powerplant with 6 additional generators, and dueto the complexity of the ship lift, the dam isnot expected to become fully operational

until about 2011.

The dam will raise the water level the thirdtime to its designed maximum water level(175 m above sea level) by the end of 2008
http://en.wikipedia.org/wiki/Three_Gorges_Damhttp://en.wikipedia.org/wiki/Three_Gorges_Dam


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THREE GORGES DAM There are two hazards uniquely

identified with the dam.

One is that sedimentation projectionsare not agreed upon, and the other isthat the dam sits on a seismic fault.

Excessive sedimentation can block thesluice gates which can cause damfailure under some conditions.

The 600 kilometer (375 mi) longreservoir has or will flood some1,300 archaeological sites .

The massive project sets records fornumber of people displaced (more than1.2 million), number of cities and townsflooded (13 cities, 140 towns, 1,350villages), and length of reservoir (morethan 600 kilometers)


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BHAKRA NANGAL


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BHAKRA NANGALDAM Bhakra Dam is a concrete

gravity damacross the SutlejRiver, near the borderbetween Punjab and HimachalPradesh in northern India.

The Bhakra-Nangal

multipurpose project is amongthe earliest river valleydevelopment schemesundertaken by IndependentIndia.

The project was conceived longbefore India became a freenation and preliminary workshad commenced in 1946


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Hydropower And The QuestionOf Scale

Of course, you will choose the single one-litre container. There is

much less packaging here because of the geometricalrelationship between surfaces and volumes:when you increase the size of a container, the outside surface

grows at a square rate while the volume inside grows at acubic rate. The same geometrical laws govern comparisonsbetween small-scale versus large-scale hydroelectric plants andtheir corresponding reservoirs.


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Small Hydro

Class Station capacity inkW

Micro Hydro Up to 100

Mini Hydro 101 2000

Small Hydro 2001 - 25000

In India, hydro projects up to 25 MW station capacity have beencategorized as Small Hydropower (SHP) projects. Further, theseare classified as:

The Ministry of Non-Conventional Energy Sources, Government ofIndia is assigned the business of SHP up to this capacity.


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Why Small Hydro Power ?

Reliable, ecofriendly, mature and proven technology.

More suited for the sensitive mountain ecology.

Can be exploited wherever sufficient water flows along small streams,

medium to small rivers.

Does not involve setting up of large dams or problems of deforestation,submergence or rehabilitation.

Nonpolluting, entails no waste or production of toxic gases,environment friendly.

Small capital investment and short gestation period.

Minimal transmission losses.

Small Hydro Development In


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Small Hydro Development InIndia

Power generating total installed capacity in India is of 1,27,056MW, which includes 33,194 MW from hydro.

About 70% of the population in India lives in rural areas. Therural energy scenario is characterized by inadequate, poor and

unreliable supply of energy services.

Realizing the fact that small hydropower projects can provide asolution for the energy problem in rural, remote and hilly areaswhere extension of grid system is comparatively uneconomical.

Along the canal systems having sufficient drops, promoting

small and mini hydro projects is one of the objectives of thePolicy on Hydro Power Development in India.

Along water distribution systems and pre and post watertreatment plants.


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S. No. Name of State Identified number of Sites

Total Capacity in MW

1 Andhra Pradesh 286 254.63

2 Arunachal Pradesh 492 1059.03

3 Assam 90 148.90

4 Bihar 92 194.02

5 Chhatisgarh 174 179.97

6 Goa 3 2.6

7 Gujarat 290 156.83

8 Haryana 22 30.05 30.05

9 Himachal Pradesh 323 1624.78

10 Jammu & Kashmir 201 1207.27

11 Jharkhand 89 170.05

12 Karnataka 230 652.61

13 Kerala 198 466.85

14 Madhya Pradesh 85 336.32

State Wise Identified Small Hydel Sites upto 25MW Capacity

State Wise Identified Small Hydro Sites upto 25


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s.No Name of State Identified Number of Sites

Total Capacity in MW

15 Maharashtra 234 599.47

16 Manipur 96 105.63

17 Meghalaya 98 181.50

18 Mizoram 88 190.32

19 Nagaland 86 181.39

20 Orissa 161 156.7621 Punjab 78 65.26

22 Rajasthan 49 27.26

23 Sikkim 68 202.75

24 Tamil Nadu 147 338.92

25 Tripura 8 9.8526 Uttar Pradesh 211 267.061

27 Uttaranchal 354 1478.235

28 West Bengal 145 182.62

29 A&N Island 6 6.40

TOTAL 4,404 10,477.34

State Wise Identified Small Hydro Sites upto 25MW Capacity

Contd .


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Main Elements Of A small hydroScheme

WeirCanalForebay

PenstockPowerhouseTailrace


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ThankYou

Documents

Hydro Power an Introduction