52

A

PROJECT REPORT ON

HYDRO PELTON WHEEL

DEPARTMENT OF DIPLOMA IN ELECTRICAL SHRI K.J. POLYTECHNIC BHARUCH

Submitted By: -

Guided By:-SHRI K. J. POLYTECHNIC(Affiliated to Gujarat technological University)

Department of Diploma in Electrical

CERTIFICATE

This is certify that . Of diploma in electrical has completed their project Electronic Motor Starter Satisfactorily during the Year 2012-13Date:-

Signature of guide

Head of Department________________

________________

Examined By:- ACKNOWLEDGEMENTThis project report shall be incomplete if we do not convey our heartfelt gratitude to those people from whom We have got considerable support and encouragement during this project report. Many people have helped, provided direction, technical information and advice at all stages of our project report and its our pleasure to say vote of thanks to all of them. However, with the help of our PROJECT guide ALPANA K UPADHAYA it seems much more interesting to write this project report than we expected.

Also we are very much thankful for our college SHRI K. J. POLYTECHNIC, which provide us a good study environment & available access to get literature. Besides our friends showed their kindly help & support in our the project report.

ABSTRACTPelton wheel is well suited for operating under high heads. A pelt on turbine has one or more nozzles discharging jets of water which strike a series of buckets mounted on the periphery of a circular disc. The runner consists of a circular disc with a number of buckets evenly spaced round its periphery. The buckets have a shape of double semi-ellipsoidal cups. The Pelton bucket is designed to deflect the jet back through 165 which is the maximum angle possible without the return jet interfering with the next bucket.

General arrangement of a Pelton wheel is shown in the Fig. For SHP schemes, Pelton wheels are easier to fabricate and are relatively cheaper. The turbines are in general, not subjected to the cavitations effect. The turbines have access to working parts so that the maintenance or repairs can be effected in a shorter time.INDEX

SR. NONAMEPAGE NO.

1.CHAPTER:1 INTRODUCTION

1.1. INTRODUCTION

1.2. STATEMENT OF UDP

2.CHAPTER: 2 PROJECT DISCRIPTION

2.1. CIRCUIT DIAGRAM & ITS WORKING

2.2. OPERATION

2.3. BLOCK DIAGRAM

2.4. COMPONENT LIST

3.CHAPTER: 3 PROJECT WORKDONE

3.1. PROJECT WORKDONE

3.2 . PROBLEM

4.CHAPTER: 4 PROJECT OUT LINE

4.1. PROJECT OUTCOME

4.2. ADVANTAGE & DISADVANTAGE

4.3. APLLICATION

4.4 FUTURE SCOPE

5.CONCLUSION

6.BIBLOGRAPHY

CHAPTER NO. 1INTRODUCTION1.1 INTRODUCTION

1.2 STATEMENT OF UDP1.1 INTRODUCTION

TURBINE

Pelton turbines are the machines which use the energy of water and convert it to mechanical energy. The mechanical energy developed by a turbine is used in running an electric generator which is directly coupled to the shaft of the turbine. The electric generator thus develops electric power, which is known as hydro-electric power.

TYPES OF HYDRO POWER PLANTS

There are three types of hydro power facilities: impoundment, diversion, and pumped storage. Some hydropower plants use dams and some do not. The images below show both types of hydropower plants.

Many dams were built for other purposes and hydro power was added later. In the United States, there are about 80,000 dams of which only 2,400 produce power. The other dams are for recreation, stock/farm ponds, flood control, water supply, and irrigation.

Hydro power plants range in size from small systems for a home or village to large projects producing electricity for utilities. They are described below.LARGE HYDRO POWERAlthough definitions vary, DOE defines large hydropower as facilities that have a capacity of more than 30 megawatts.

SMALL HYDROPOWER

Although definitions vary, DOE defines small hydropower as facilities that have a capacity of 100 kilowatts to 30 megawatts.

MICRO HYDROPOWERA micro hydropower plant has a capacity of up to 100 kilowatts. A small or micro-hydroelectric power system can produce enough electricity for a home, farm, ranch, or village.

Water is cheapest source of power. From the words Hydro plant itself suggest that electric power to be produced directly from water by means of some plant setup. Hydro power is a conventional renewable source of energy which is clean, free from pollution and generally has a good environmental effect. In hydro electric plants energy of water is utilized to move the turbines which in turn run the electric generators. The energy of water utilized for power generation may be kinetic or potential .At present India has a hydro potential of 87000MW out of which only 35% is used. Next to thermal power, hydro power is important in regard to power generation .In some countries like Norway Almost total power generation is hydro based. The total hydro potential of the world is 5000MW.

1.2 STATEMENT OF UDPWHY WE SELECT THIS PROJECT?We have selected this project because we studied about it. It is also possible to make model of it. It operates by use of water which is the conventional source which we can get easily.

Hydro power plant operates by water, so its clean. Hydro power plant does not pollute the air like power plant that burn fossil fuels, such as coal or natural gas.

Hydro power plant is comparatively faster than thermal power plant. Engineer can control the flow or water through the turbines of produce electricity on demand.

CHAPTER NO. 2

PROJECT DESCRIPTION

2.1 CIRCUIT DIAGRAM & ITS WORKING

2.2 FLOW CHART2.3 DESIGN2.4 COMPONENT LIST

2.1 CIRCUIT DIAGRAM & ITS WORKING

HOW HYDRO POWER WORKS It uses the potential energy of water of water stored in a reservoir. The water from the reservoir through a penstock and then forced through nozzle or nozzles before reaching the turbine. The hydraulic turbine converts the kinetic energy of water under pressure into mechanical energy. The shaft of the turbine is coupled to a generator that generates electricity The electricity generated is fed to the step-up transformer to increase its voltage. Power is fed to the transmission lines for distribution. The output power of Hydro power plant depends on the head of water stored in the reservoir and the quantity of water discharged.

2.2 FLOW CHARTStatrt

water storage

gate operat

water flow

turbine rotate

dynamo rotate

power generate

close

2.3 DESIGNMANUFACTURING PARTS 1. Supporting frame.

2. PELTON Wheel Turbine3. Pulley pelton turbine4. Generator5. Pulley generatorASSEMBLY DRAWING

BUCKETS for a bucket we decided to purchase no. of spoon instead of casting a bucket its easy and economical way for the turbine bucket.

SUPPORTING FRAME:as a supporting frame we used 2.5 X 2.5 cm L section angle of M.S This gives a base for whole structure. The wheel will rest on a vertical plate size of 33 cm in height and 1.1 X 4.8 cm in cross-section.PART DRAWING

PULLEY

pulley is made of M.S which is mounted on axle of the wheel which has a outer dia of 18 cm. and a hub of 5 cm in dia.

WHEEL

for installing a bucket we liked to use bicycle tyre rim of dia about to 32 cm. all buckets are installed on a wheel periphery by brazing.

DESIGN OF PELTON WHEEL TURBINE

SPECIFIC SPEEDThe specific speed of any turbine is the speed in i.e. of a turbine geometrically similar to the actual turbine but of such a size that under corresponding conditions it will develop 1 metric horsepower when working under unit head.

Where, Ns = specific speed

P = power in HP

GOVERNING OF TURBINESAll the modern turbines are directly coupled to the electric generators. The generators are always required to run at constant speed irrespective of the variations in the load. This constant speed N of the generator is given by the expression

Where,f = frequency (usually 50)

p = numbers of pairs of poles

1. WATER HAMMERA gate or valve at the end of the penstock pipe controls the discharge to the turbine. As soon as this governor regulated gate opening is altered, the pipe flow has to be adjusted to the new magnitude of flow. In doing so, there are rapid pressure oscillations in the pipe, often accompanied by a hammering like sound. Hence this phenomenon is called as water hammer.

2. JET SPEEDThe velocity of flow of the jet depends upon the total net head H at the base of the nozzle and is given by the nozzle equation:

V Cv2gH) 1/2

Where the discharge coefficient velocity of the nozzle is taken as 0.95.

3. BUCKET SPEED

The bucket speed should be half of the jet speed. In practice, losses in the turbine cause the maximum efficiency to occur at slightly less than a half, typically 0.46.

Design of Pelton Wheel

RUNNER DIAMETERRunner diameter can be found out from the rpm equation.

Where, N = runner speed (rpm)

H = net head

NOZZLE DIAMETERThe nozzle diameter is given by the nozzle equation:

JET RATIOJet ratio D/d is a size parameter for the turbine. It has a value in a range of 10 to 24. For the high efficiency Pelton wheel design, the ratio of the runner diameter to the nozzle should be more than 9.

NUMBER OF BUCKETS

The number of buckets required for the efficient operation of the Pelton turbine is calculated as:

In practice, the selection and the detail design of the turbine units are carried out by the manufactures based on the model performances. PELTON WHEEL BLADEThe above analysis of impact of jets on vanes can be extended and applied to analysis of turbine blades. One particularly clear demonstration of this is with the blade of a turbine called the pelton wheel. The arrangement of a pelton wheel is shown in the figure below. A narrow jet (usually of water) is fired at blades which stick out around the periphery of a large metal disk. The shape of each of these blade is such that as the jet hits the blade it splits in two (see figure below) with half the water diverted to one side and the other to the other. This splitting of the jet is beneficial to the turbine mounting - it causes equal and opposite forces (hence a sum of zero) on the bearings.

Pelton wheel arrangement and jet hitting cross-section of blade.LATHE MACHINE

AHeight of Center 165 mm

BLength 1839 mm

CSwing Over Saddle 203 mm

DNo. of Spindle Possible 8

ERange of Spindle Speed 240 to 790 rpm

FRange of Gross Feed 0.008 to 0223 mm

GRange of width worth Thread per inch 4 to 120 TPI

HNet wet of Machine690 kg

Specification of tool and equivalent required for the project cutting tools:-

Carbide Tool

H.S.S. Tool

Drill Different Sizes MACHINE USED AND THEIR SPECIFICATION

Various machine required for project as under:-

1) Lathe Machine:

AMax. diameter of mod to cat 180 mm

BStrike75 to 150 mm

CNo. of Stroke per minute 60

DBlade Size350 mm

EMotor 1 hp

FApproximate Wt.225

COST OF MATERIAL

Our Project Construction for rewarded material as cost above local market Fabrication and job work charge extra.

No.ParticularCost

1Spoons700

2Shaft150

3Water jet50

4Frame structure2500

5Led Lamp10

6Generator200

8.Pulley700

2.4 ESSENTIAL ELEMENTS OF HYDRO ELECTRIC POWER PLANT The following are the essential element of hydro electric power plant

1) Catchments area

2) Reservoir

3) Dam

4) Spillways

5) Conduits

6) Surge tanks

7) Prime movers

8) Draft tubes

9) Powerhouse and equipment

OVER VIEW OF HYDRO ELECTRIC POWER PLANT

The description of various elements of hydro electric power plant is follows

(1) CATCHMENT AREA

The whole area behind the dam draining into a stream or river across which the dam has been built at a suitable place, is called catchments area

(2) RESERVOIR

The water reservoir is the primary requirement of hydro power Plant. A reservoir is employed to store water which is further utilized

To a generate power by running the hydraulic turbines. Reservoir may be of the following two types:

(A) Natural

(B) Artificial

A natural reservoir is a lake in high mountains.

An artificial reservoir is built by erecting a dam across the river.

Water held in upstream reservoir is called storage whereas water behind the dam at the plant is called pondage.

(3) DAM

A dam is barrier to confine or raise water for storage or diverts to create a hydraulic head. A hydroelectric dam diverts the flow from the divert the turbines and usually increases the head. A reservoir stores water by raising its level.

Dams are built of concrete or stone masonry, earth or rock fill, or timber. Masonry dams may be the solid gravity, buttress or arch type. A barrage is a diversion dam, especially at a tidal power project. A weir is a low overflow dam across a stream for measuring flow or maintain water lower, as at a lake outlet, A dike is an embankment to confine water; a levee is a dike near the bank of river to keep low land from being flowed.THE DIFFERENT TYPES OF DAMS ARE AS FOLLOWSA. Fill dams

Earth dams

Rock-fill dams

B .Masonry dams

solid gravity dams

Buttress dams

Arch dams

C. Timber dams

SELECTION OF SITE FOR DAMSThe following points should be taken into consideration while selecting the site for a dam.

1. For achieving economy the water storage should be largest for the

minimum possible height and length.

2. For safe and cheap construction good foundation should be available at a moderate depth.

3. Good and suitable basin should be available.

4. Material construction should be available at a dam site or near by.

5. The value of property and land likely to be submerged by the

submerged by proposed dam should be sufficiently low sufficient Low

in comparison with the benefit expected from project.

6. The site of the dam should be easily accessible in all the reasons. It

should be feasible to connect the site with good lines of comm.

7. Over all cost of construction and maintains of the dam should be taken

into consideration.(4) SPILLWAYS

When the water enters the reservoir basin, the level of water in basin rises. This rise arranged to be of temporary nature because Accumulation of water endangers the stability dam structure. To Relieve reservoir of the excess water contribution, a structure is provided in the body of a dam .this Safe guarding structure is called a spillway

Spillways should be the following requirements

1. It should provide structure stability to the dam under all condition of floods.

2. It should be able to pass the designed flood without raising reservoir level

above high flood level.

3. It should have an efficient operation.

4. It should have an economical section.

TYPES OF SPILLWAYSFollowing are some types of spillways:

a) Overall spillways or solid gravity spillway

b) Trough spillways

c) Side channel spillways

d) Saddle spillways

e) Emergency spillways

f) Shaft or glory hole spillways

g) Siphon spillways

(5) CONDUITS

An Ahead race is a channel which leads to the water to a Turbine and a tail race is a channel which conduits water from the wheel.

The conduits may be open or close.

Open conduits .canals & flumes

Closed conduits ..tunnels, pipelines, penstocks

CANALA canal is an open channel way excavated in natural ground. It has to follow the contour of the ground, with perhaps gradient Corresponding to the head loss.

FLUME A flume is a channel erected on the surface of supported above ground on a trestle .a flume might be used with a canal to cross be vine or where the slope of the ground is greater than the hydraulic gradient.

TUNNELIt is a closed channel excavated through a natural obstruction Such as a ridge of higher land between the dam and the powerhouse a tunnel across a bend in the river might be cheaper than a conduit that goes around. Tunnels are also commonly used in diverting water from one drainage area to another, where the divide between watersheds is higher than the reservoir.

PIPELINE

A pipe line is a closed conduit usually supported on or above the Surface of the land. When a pipeline is laid on the hydraulic gradient, it is called a flow.

PENSTOCK It is a conduit for supplying water under pressure to a turbine

ADVANTAGES AND LIMITATIONS OF DIFFERENT TYPES OF CONDUITSA. Open channels are generally the most expensive, but the cost of a Flume increases with a height of the trestle.

B. Where the land is fairly level at the head water elevation between the dam and powerhouse site a canal would be feasible, but not many Requirement.

C. Tunnels are generally the most convey type of conduit for a given Length but just field if their use results in distance. While ordinarily Tailraces are open channels, tunnels are used for the discharge from the underground hydro station.

D. Penstocks are used where the slope is too great for a canal, especial for the final stretch the diversion system where the land and pitch steep to the power house. Surge tanks or other measures necessary to prevent damage in closed conduits due to pressure.

(6) SURGE TANKSA surge tank is a small reservoir or tank in which water level rise or fall to reduce the pressure swings so that they are not transmitted in full to closed circuits. In general a surge tank serves

The following purposes

A. To reduce the distance between free water surface and turbine There by reducing the water hammer effect(the water hammer means that the change in pressure rapidly above or below normal pressure caused by sudden change in the rate of water flow through the pipe, according to he demand of prime mover )on penstock and also protect upstream tunnel from high pressure rises.

B. To serve as a supply tank to the turbine when the water in the pipe is accelerating during increased load conditions and as a storage tank when the water is decelerating during reduced load conditions.

TYPES OF SURGE TANK

THE DIFFERENT TYPES OF SURGE TANKS IN USE ARE1. Simple surge tank

2. Inclined surge tank

3. The expansion chamber and gallery surge tank

4. Restricted orifice surge tank

5. Differential surge tank

1. simple surge tank

A simple surge tank is a vertical stand pipe connected to the penstocks. In the surge tank if the overflow is allowed, the rise in pressure can be eliminated but overflow surge tank is seldom satisfactory and usually an economical .it is always desirable to place the surge tank on ground surface above the penstock line.

2. Inclined surge tank When a surge tank is inclined to the horizontal its effective water surface increases and therefore, lesser height surge tank is required of the same diameter if it is inclined or lesser diameter tank is required for the same height. But it is more costlier than other.

3. Expansion chamber surge tank This type of a surge tank has an expansion tank at a top and expansion gallery at the bottom ,these expansions limit the extreme surges .the upper expansion chamber must be above the maximum reservoir level and bottom gallery must be below the steady running level in the surge tank.

4. Restricted orifice surge tank It is also called throttled surge tank. The main object of providing a throttle or restricted orifice is to create an appreciable friction loss when the water is flowing to or from the tank. When the load is on the turbine is reduced, the surplus water passes though the throttle and a retarding head equal to the loss due to the throttle is built up in the conduit.

5. Differential surge tankA differential surge tank has a riser with a small hole at its lower end through which water enters in it. The function of the surge tank depends upon the area of hole.

(7) PRIMEMOVERS

In a hydraulic power plant the prime mover converts the energy of water into mechanical energy and further into electrical energy. These machines are classified on the basis of the action of water on moving blades .as per action of the prime mover, they are

CLASSIFIED AS:General Classification of Turbines Turbines are hydraulic machines that convert energy into rotating mechanical energy which in turn generators to produce electrical energy. Originally developed from the water wheels, hydraulic turbines are the prime mortars of importance in modern water power development. According to their hydraulic action, turbines are broadly divided into two classes.

(1) IMPULSE TURBINE:

IMPULSETURBINE

Impulse turbines are more efficient for high heads. At the inlet to the turbine runner, pressure head can be completely converted into kinetic head in the form of a jet of water issuing from one or more nozzles. The free jet will be at atmospheric pressure before as well as after striking the vanes. The turbines are regulated by nozzles which may be a simple straight flow type or a deflector type. The impulse turbines are commonly represented by Pelton Wheels. Turgo turbine is also an impulse turbine but with different buckets, when compared with Pelton. Turgo and cross flow turbines are relatively new developments in this class.

The main advantages of these turbines are:

They can be easily adapted to power variation with almost constant efficiency.

The penstock overpressure and the runner over speed control are easier.

The turbine enables an easier maintenance.

Due to the jet the manufacturer of these turbines impose a better solid particle control, conducting, consequently, to a lower abrasion effect.

(2) REACTION TURBINE:

A turbine can be made to rotate under the action of water flowing under pressure through the runner. In such turbines the penstocks, the inlet passage to the runner, passage between the runner vanes, all form a continuous passage for the flow under a pressure which continuously decreases from inlet to outlet. The turbine runner directly converts both kinetic energy as well as the pressure energy into mechanical energy. Reaction turbines are represented in modern practice by two principal types:

REACTION TURBINE

the Francis turbine where the flow is directed radial to the runner axis and the Propeller type where the flow is axial to the runner axis. Propeller turbines may be fixed blade or adjustable blade types. Kaplan turbine has adjustable blades.

(3) BULB TURBINE

The turbine and generator is sealed unit placed directly in the water stream.

Startle The generator is attached directly tithe perimeter Of the Turbine.

BULB TURBINE

(4) TUBE TURBINE

The penstock bends just before or after the runner, allowing straight line connection to the generator.(5) KAPLAN TURBINE

Kaplan hydro power turbine Both the blades and the wicket gates are adjustable, allowing for a wider range of operation.

FRANCIS TURBINE Francis hydropower turbine Credit: A Francis turbine has runner with fixed buckets (vanes), usually nine or more. Water is introduced just above the runner and all around it and then falls through, causing it to spin. Besides the runner, the other major components are the scroll case, wicket gates, and draft tube.

Kinetic and Hydropower Technologies Program: Types of Hydropower Turbines Kinetic energy turbines, so called free-flow turbines, generate electricity from the kinetic energy present in flowing water rather than the potential energy from the head. The systems mayOperate in rivers, manmade channels, tidal waters, or ocean currents. Kinetic systems utilize theater stream's natural at hay. They do not require the diversion of water through manmade

Channels, riverbeds, or pipes, although they might have applications in such conduits. Kinetic systems do not require large civil works; however, they cause existing structures such as bridges, tailraces and channels.

The main advantages of these turbines are:

It needs lesser installation space.

It provides a greater net head and a better protection against downstream high flood levels.

It can have greater runner speed.

It can attain greater efficiencies for high power values.

In order to distinguish different turbines, the hydraulically salient features like pressure, head, flow direction and magnitude, speed and power etc. The general classification of hydraulic turbines is illustrated in Fig.

2. PELTON WHEEL TURBINEPelton wheel is well suited for operating under high heads. A pelt on turbine has one or more nozzles discharging jets of water which strike a series of buckets mounted on the periphery of a circular disc. The runner consists of a circular disc with a number of buckets evenly spaced round its periphery. The buckets have a shape of double semi-ellipsoidal cups. The Pelton bucket is designed to deflect the jet back through 165 which is the maximum angle possible without the return jet interfering with the next bucket.

BUCKET

General arrangement of a Pelton wheel is shown in the Fig.5.5. For SHP schemes, Pelton wheels are easier to fabricate and are relatively cheaper. The turbines are in general, not subjected to the cavitations effect. The turbines have access to working parts so that the maintenance or repairs can be effected in a shorter time.

PELTON TURBINECOMPARISON OF TURBINES

(8) DRAFT TUBES

The draft to serves the followings two purposes:

1. It allows the turbine to be se above tail water level, without loss of Head to facilitate inspection and maintenance.

2. It regain by diffuser action, the major portion of the kinetic

Energy delivered to it from the runner.

TYPES OF DRAFT TUBESA. The straight conical or concentric tube

B. The elbow type

A. The straight conical tube:The conical type is generally based on law powered units for all specific speeds and high head units. The range from. 4 to 6. The length from 3 to 4 times the diameter.

B. Elbow type:

The elbow type of tube is measured with most turbine installation. With this type the vertical portion begins with a conical section .which gradually flattens in the elbow section and then discharges horizontally through sustained regular sections to the tail race.(9) POWER HOUSE AND EQUIPMENTS:-

A Power house should have a stable structure and its lay out should have stable structure and its lay out should be such that adequate space is provided around the equipment .so that dismantling and repairing may easily carried out.

A power house mostly comprises of the followings sub division:A. The sub structure:

This parts of the power house extends from the generates of rock & houses most of the generating equipments in case of Francis Turbine Kaplan turbine. The substructure not only accommodates various equipments but draft as well.

B. Intermediate structure:

It is that part of the structure which extends from the top of the Draft tube to top of the generator foundation.

C. The superstructure: This part of the structure lies above the generator level .It houses mostly the cranes which handle the heavy equipment in the substructure.

FOLLOWING IMPORTANT EQUIPMENT MAY BE PROVIDED IN A POWER HOUSE Hydraulic turbines

Electric generators

Governors

Gate valves, Relief valves

Water circulating pumps

Air duct

Reactors

Cranes

Switch board equipment and instruments

Oil circuit breakers

Storage batteries

Low tension &high tension bar

CHAPTER NO. 3PROJECT WORK DONE

3.1 PROJECT WORK DONE

3.2 PROBLEM3.1 PROJECT WORK DONE

NO.PARTICULARSMONTH

1.FINDING THE TITAL OF PROJECTAUGUST 2012

2.COLLECTION OF DATA FROM INTERNETSEPTEMBER 2012

3.PREPARATION OF INITIAL REPORT WITH PRESENTATIONOCTOBER 2012

4.COLLECT COMPONENT

5.ANALYSIS OF CIRCUIT DIAGRAM

6.PREPARATION OF THE REPORT WITH PRESENTATIONNOVEMBER 2012

3.2 PROBLEMCHAPTER NO. 4

PROJECT OUTLINE

4.1 PROJECT OUTCOMES

4.2 ADVANTAGES & DISADVANTAGES

4.1 PROJECT OUTCOMESNO.PARTICULARSMONTH

1.COLLECT THE COMPONENT FROM MARKETJAN 2013

2.DESIGN CIRCUITFEB 2013

4.TESTING OF CIRCUIT ANALYSISMARCH 2013

5.PREPARE FINAL REPORTMARCH 2013

6.SUBMISSIONAPRIL 2013

4.2 ADVANTAGES & DISADVANTAGES4.1.1. ADVANTAGES OF HYDRO POWER

Hydro power offers advantages over other energy sources but faces unique environmental challenges.

ADVANTAGES

Hydro power is a fueled by water, so it's a clean fuel source. Hydro power doesn't pollute the air like power plants that burn fossil fuels, such as coal or natural gas.

Hydropower relies on the water cycle, which is driven by the sun, thus it's a renewable power source.

Hydropower is generally available as needed; engineers can control the flow of water through the turbines to produce electricity on demand.

Hydro power plants provide benefits in addition to clean electricity. Impoundment hydro power creates reservoirs that offer a variety of recreational opportunities, notably fishing, swimming, and boating. Most hydro power installations are required to provide some public access to the reservoir to allow the public to take advantage of these opportunities. Other benefits may include water supply and flood control4.2.2. DISADVANTAGES Hydro power can impact water quality and flow. Hydropower plants can cause low dissolved oxygen levels in the water, a problem that is harmful to riparian (riverbank) habitats and is addressed using various aeration techniques, which oxygenate the water. Maintaining minimum flows of water downstream of a hydropower installation is also critical for the survival of riparian habitats.

Hydro power plants can be impacted by drought. When water is not available, the hydropower plants can't produce electricity.

New hydro power facilities impact the local environment and may compete with other uses for the land. Those alternative uses may be more highly valued than electricity generation. Humans, flora, and fauna may lose their natural habitat. Local cultures and historical sites may be impinged upon. Some older hydropower facilities may have historic value, so renovations of these facilities must also be sensitive to such preservation concerns and to impacts on plant and animal CONCLUSION

Oil price are likely to be more than $50 per barrel for all times to come. Its supply will not to be enough to fulfill Indias growing energy Requirements. While nuclear energy, solar energy &wind energy are cited as alternatives to oil, hydel power is a better option. Unfortunately, Environmentalists have sabotaged developments of hydel power.

Take the case of the Tehri dam, which was consistently opposed and delayed. Had the project been completed without repeated postponements ,the cost of power would have been 78 paise per kilowatt hour ; now it is 293 paise per kilowatt hour and yet it is a very viable project. Besides Irrigation,it will supply 200 cusecs of water to UP and 300 cusecs to water starved Delhi .The Narmada project also supplies power at cheap rates, irrigation and drinking water .Yet The implementation of the project was delayed in the name of environment.

Data by the central Electricity Authority shows that over a long period a hydel projects is much cheaper than a thermal project. As hydel projects get older, their generation costs decreases since fuel cost remains zero, while those of thermal projects would go up, on account of escalating fuel costs.

The hydel plants of Matatila , Bhakra, Rihand, Gandhisagar and koyna set up in the 60s produce power at about 10 -18 paisa/KWH. Thermal plants set up in the 60s ,such as paras,Nellore and Bhusaval, produce power at 125-200 paise/KWH.This is only one example.

BIBLOGRAPHY1. www.ossberger.de/cms/en/hydro/pelton-turbine/2. www.canyonhydro.com/3. www.hydro-turbines.com/4. Book power plant engineering A.K. RAJA5. Power plant engineering by: R K RAJPUT

6. Power plant engineering by: P. K. NAG

7. Power systems engineering by: V. K. MEHTA8. www.wikipedia.org/turbine.htm

9. www.howstuffworks.com/hydro.htm