This undertaking paper surveies the potency of hydroelectric energy as a manner to efficaciously bring forth. usage and shop renewable energy through the clean gravitative possible energy of stored H2O. Nuclear and coal fired workss could make alter power end product to accomplish demand but at highly high care cost. Nuclear workss besides being a good beginning of uninterrupted energy has a high opportunity of presenting jeopardy to the environment. Coal and fossil fuel fired power workss on the other manus can non be depended on because the beginning will decrease someday. Therefore. alternate methods have to be explored in order to happen a renewable and sustainable energy for the future coevalss. This undertaking paper will analyze the benefits of hydroelectric energy as a possible and of import energy beginning for a sustainable hereafter.
Introduction
1. 0 Hydropower
Hydropower is a renewable energy beginning based on the natural H2O rhythm. Hydropower is the most mature. dependable and cost-efficient renewable power coevals engineering available. Hydropower schemes frequently have important flexibleness in their design and can be designed to run into base-load demands with comparatively high capacity factors. or have higher installed capacities and a lower capacity factor. but run into a much larger portion of peak demand. Hydropower is the largest renewable energy beginning. and it produces about 16 % of the world’s electricity and over four-fifths of the world’s renewable electricity. Presently. more than 25 states in the universe depend on hydropower for 90 % of their electricity supply ( 99. 3 % in Norway ) . and 12 states are 100 % reliant on hydro. Hydro produces the majority of electricity in 65 states and plays some function in more than 150 states. Canada. China and the United States are the states which have the largest hydropower coevals capacity. Hydropower is the most flexible beginning of power coevals available and is capable of reacting to demand fluctuations in proceedingss. presenting base-load power and. when a reservoir is present. hive awaying electricity over hebdomads. months. seasons or even old ages.
One cardinal advantage of hydropower is its matchless “load following” capableness ( i. e. it can run into load fluctuations minute-by-minute ) . Although other workss. notably conventional thermic power workss. can react to lade fluctuations. their response times are non as fast and frequently are non as flexible over their full end product set. In add-on to grid flexibleness and security services ( whirling modesty ) . hydropower dike with big reservoir storage be used to hive away energy over clip to run into system extremums or demand decoupled from influxs. Storage can be over yearss. hebdomads. months. seasons or even old ages depending on the size of the reservoir.
As a consequence of this flexibleness. hydropower is an ideal complement to variable renewables as. when the Sun radiances or the air current blows. reservoir degrees can be allowed to increase for a clip when there is no air current or sunlight. Similarly. when big raging up or down of supply is needed due to additions or lessenings in solar or wind coevals. hydro can run into these demands. Hydroelectric bring forthing units are able to get down up rapidly and run expeditiously about immediately. even when used merely for one or two hours. This is in contrast to thermal works where start-up can take several hours or more. during which clip efficiency is significantly below design degrees. In add-on. hydropower workss can run expeditiously at partial tonss. which is non the instance for many thermic workss. Reservoir and pumped storage hydropower can be used to cut down the frequence of start-ups and closures of conventional thermic workss and keep a balance between supply and demand. thereby cut downing the load-following load of thermic workss.
1. 1Hydropower Technologies
Hydropower has been used by world since antediluvian times. The energy of falling H2O was used by the Greeks to turn water wheels that transferred their mechanical energy to a crunching rock to turn wheat into flour more than 2000 old ages ago. In the 1700s. mechanical hydropower was used extensively for milling and pumping. The modern epoch of hydropower development began in 1870 when the first hydroelectric power works was installed in Cragside. England. The commercial usage of hydropower started in 1880 in Grand Rapids. Michigan. where a dynamo driven by a H2O turbine was used to supply theater and shop forepart illuming. These early hydropower workss had little capacities by today’s criterions but pioneered the development of the modern hydropower industry. Hydropower schemes range in size from merely a few Watts for pico-hydro to several GW or more for large-scale undertakings. Larger undertakings will normally incorporate a figure of turbines. but smaller undertakings may trust on merely one turbine. The two largest hydropower undertakings in the universe are the 14 GW Itaipu undertaking in Brazil and the Three Gorges undertaking in China with 22. 4 GW. These two undertakings entirely produce 80 to 100 TWh/year.
Large hydropower systems tend to be connected to centralized grids in order to guarantee that there is adequate demand to run into their coevals capacity. Small hydropower workss can be. and frequently are. used in stray countries off-grid or in mini-grids. In stray grid systems. if big reservoirs are non possible. natural seasonal flow fluctuations might necessitate that hydropower workss be combined with other coevals beginnings in order to guarantee uninterrupted supply during dry periods. Hydropower transforms the possible energy of a mass of H2O fluxing in a river or watercourse with a certain perpendicular autumn ( termed the “head” ) . The possible one-year power coevals of a hydropower undertaking is relative to the caput and flow of H2O. Hydropower workss use a comparatively simple construct to change over the energy potency of the streamlined H2O to turn a turbine. which. in bend. provides the mechanical energy required to drive a generator and produce electricity.
1. 2 The chief constituents of a conventional hydropower works
1. 2. 1Dam Most hydropower workss rely on a dike that holds back H2O. making a big H2O reservoir that can be used as storage. There may besides be a de-silter to get by with sediment build-up behind the dike. 1. 2. 2Intake. sluicegate and rush chamber
Gates on the dike unfastened and gravitation conducts the H2O through the sluicegate ( a pit or grapevine ) to the turbine. There is sometimes a caput race before the sluicegate. A surge chamber or armored combat vehicle is used to cut down rushs in H2O force per unit area that could potentially damage or take to increased emphasiss on the turbine. 1. 2. 3Turbine
The H2O strikes the turbine blades and turns the turbine. which is attached to a generator by a shaft. There is a scope of constellations possible with the generator above or following to the turbine. The most common type of turbine for hydropower workss in usage today is the Francis Turbine. which allows a side-by-side constellation with the generator. 1. 2. 4Generators
As the turbine blades bend. the rotor inside the generator besides turns and electric current is produced as magnets rotate inside the fixed-coil generator to bring forth jumping current ( AC ) .
1. 2. 5 Transformer
The transformer inside the human dynamo takes the AC electromotive force and converts it into higher-voltage current for more efficient ( lower losingss ) long-distance conveyance.
1. 2. 6Transmission lines
Send the electricity generated to a grid-connection point. or to a big industrial consumer straight. where the electricity is converted back to a lower electromotive force current and fed into the distribution web. In distant countries. new transmittal lines can stand for a considerable planning hurdle and disbursal. 1. 2. 7Outflow
Finally. the used H2O is carried out through grapevines. called tailraces. and re-enters the river downstream. The outflow system may besides include “spillways” which allow the H2O to short-circuit the coevals system and be “spilled” in times of inundation or really high influxs and reservoir degrees.
The H2O used to drive hydropower turbines is non “consumed” but is returned to the river system. This may non be instantly in forepart of the dike and can be several kilometers or farther downstream. with a non undistinguished impact on the river system in that country. However. in many instances. a hydropower system can ease the usage of the H2O for other intents or supply other services such as irrigation. inundation control and/or more stable imbibing H2O supplies. It can besides better conditions for pilotage. fishing. touristry or leisure activities. The human dynamo contains most of the mechanical and electrical equipment and is made of conventional edifice stuffs although in some instances this possibly resistance. The primary mechanical and electrical constituents of a little hydropower works are the turbines and generators. Turbines are devices that convert the energy from falling H2O into revolving shaft power. There are two chief turbine classs: “reactionary” and “impulse” . Impulse turbines pull out the energy from the impulse of the streamlined H2O. as opposed to the weight of the H2O. Reaction turbines extract energy from the force per unit area of the H2O caput.
The most suited and efficient turbine for a hydropower undertaking will depend on the site and hydropower strategy design. with the cardinal considerations being the caput and flow rate. The Francis turbine is a reactionist turbine and is the most widely used hydropower turbine in being. Francis turbines are extremely efficient and can be used for a broad scope of caput and flow rates. The Kaplan reactionist turbine was derived from the Francis turbine but allows efficient hydropower production at caputs between 10 and 70 meters. much lower than for a Francis turbine. Impulse turbines such as Pelton. Turgo and cross-flow ( sometimes referred to as Banki-Michell or Ossberger ) are besides available. The Pelton turbine is the most normally used turbine with high caputs. Banki- Michell or Ossberger turbines have lower efficiencies but are less dependent on discharge and have lower care demands.
HYDROPOWER PLANT
2. 0Classification of Hydro Power Plants
Small hydropower. where a suited site exists. is frequently a really cost-efficient electric energy coevals option. It will by and large necessitate to be located near to tonss or bing transmittal lines to do its development economic. Small hydropower schemes typically take less clip to
concept than large-scale 1s although planning and blessing procedures are frequently similar. Large-scale hydropower workss with storage can mostly de-couple the timing of hydropower coevals from variable river flows. Large storage reservoirs may be sufficient to buffer seasonal or multi-seasonal alterations in river flows. whereas smaller reservoirs may be able to buffer river flows on a day-to-day or hebdomadal footing.
Hydropower workss can be constructed in a assortment of sizes and with different features. In add-on to the importance of the caput and flow rate. hydropower strategies can be put into the undermentioned classs: 2. 1Run-of-river hydropower undertakings have no. or really small. storage capacity behind the dike and coevals is dependent on the timing and size of river flows. 2. 1. 1Reservoir ( storage ) hydropower Reservoir ( storage ) hydropower strategies have the ability to hive away H2O behind the dike in a reservoir in order to de-couple coevals from hydro influxs. Reservoir capacities can be little or really big. depending on the features of the site and the economic sciences of dam building. 2. 1. 2 Pumped storage
hydropower strategies use off-peak electricity to pump H2O from a reservoir located after the tailrace to the top of the reservoir. so that the wired storage works can bring forth at peak times and supply grid stableness and flexibleness services.
2. 2Environmental Impacts
Hydro-electric power workss have many environmental impacts. some of which are merely get downing to be understood. These impacts. nevertheless. must be weighed against the environmental impacts of alternate beginnings of electricity. Until late there was an about cosmopolitan belief that hydro power was a clean and environmentally safe method of bring forthing electricity. Hydro-electric power workss do non breathe any of the standard atmospheric pollutants such as C dioxide or sulfur dioxide given off by fossil fuel fired power workss. In this regard. hydro power is better than firing coal. oil or natural gas to bring forth electricity. as it does non lend to planetary heating or acid rain. Similarly. hydro-electric power workss do non ensue in the hazards of radioactive taint associated with atomic power workss.
A few recent surveies of big reservoirs created behind hydro dikes have suggested that disintegrating flora. submerged by deluging. may give off measures of nursery gases tantamount to those from other beginnings of electricity. If this turns out to be true. hydro-electric installations such as the James Bay undertaking in Quebec that flood big countries of land might be important subscribers to planetary heating. Run of the river hydro workss without dikes and reservoirs would non be a beginning of these nursery gases.
The most obvious impact of hydro-electric dike is the implosion therapy of huge countries of land. much of it antecedently forested or used for agribusiness. The size of reservoirs created can be highly big. The La Grande undertaking in the James Bay part of Quebec has already submerged over 10. 000 square kilometers of land ; and if future programs are carried out. the eventual country of implosion therapy in northern Quebec will be larger than the state of Switzerland. Reservoirs can be used for guaranting equal H2O supplies. supplying irrigation. and diversion ; but in several instances they have flooded the fatherlands of native peoples. whose manner of life has so been destroyed. Many rare ecosystems are besides threatened by hydro-electric development.
2. 3Hydro-electric Power Plants
Hydro-electric power workss capture the energy released by H2O falling through a perpendicular distance. and transform this energy into utile electricity. In general. falling H2O is channelled through a turbine which converts the water’s energy into mechanical power. The rotary motion of the H2O turbines is transferred to a generator which produces electricity. The sum of electricity which can be generated at a hydro-electric works is dependent upon two factors. These factors are ( 1 ) the perpendicular distance through which the H2O falls. called the “head” . and ( 2 ) the flow rate. measured as volume per unit clip. The electricity produced is relative to the merchandise of the caput and the rate of flow. The followers is an equation which may be used to approximately find the sum of electricity which can be generated by a possible hydro-electric power site
Power ( kilowatt ) = 5. 9 ten FLOW x HEAD
In this equation. FLOW is measured in three-dimensional metres per second and HEAD is measured in metres.
Based on the facts presented above. hydro-electric power workss can by and large be divided into two classs. “High head” power workss are the most common and by and large use a dike to hive away H2O at an increased lift. The usage of a dike to attach H2O besides provides the capableness of hive awaying H2O during showery periods and let go ofing it during dry periods. This consequences in the consistent and dependable production of electricity. able to run into demand. Heads for this type of power works may be greater than 1000 m. Most big hydro-electric installations are of the high caput assortment. High caput workss with storage are really valuable to electric public-service corporations because they can be rapidly adjusted to run into the electrical demand on a distribution system.
“Low head” hydro-electric workss are power workss which by and large utilize caputs of merely a few metres or less. Power workss of this type may use a low dike or weir to impart H2O. or no dike and merely utilize the “run of the river” . Run of the river bring forthing Stationss can non hive away H2O. therefore their electric end product varies with seasonal flows of H2O in a river. A big volume of H2O must go through through a low caput hydro plant’s turbines in order to bring forth a utile sum of power. Hydro-electric installations with a capacity of less than approximately 25 MW ( 1 MW = 1. 000. 000 Watts ) are by and large referred to as “small hydro” . although hydro-electric engineering is fundamentally the same regardless of bring forthing capacity.
2. 4Categories of Hydroelectric power works
Hydroelectric works have few type of classs which makes its different harmonizing to its specifications due to its capacity of H2O flow ordinance or hydraulic features. caput under which they work. the footing of operation burden supplied. storage and pondage. works capacity. location and topography. and its turbine features harmonizing to its specific velocity. Based on their hydraulic features or capacity pes H2O flow ordinance. the hydro power workss may be categorised as tally of river workss. storage works. and pumped storage works.
2. 4. 1Run of river workss
As the name suggests. these workss utilize the flow as it runs through the twelvemonth. without any storage add the benefit thereof. During the rainy season high H2O flow is available and if the power works is non able to utilize this big flow of H2O some measure of H2O is allowed to flux over dam wasteweirs as waste. On the other manus during dry season. the power produced by such workss will be less. due to low flow rates of H2O. Such workss may be farther sub-divided into Run of river workss without pondage. and Run of river workss with pondage.
2. 4. 2Run of river workss without pondage
Such workss have perfectly no pondage available and utilize the H2O merely as it comes in the watercourse. The dike constructed at the site may be for some intent other than of hydro power development. For illustration it may seize with teeth needed merely to raise the H2O degree for deviating it into an irrigation. Channel on the bank of merely to keep a certain degree for the pilotage intent. the development of hydro power being incidental. The flow may be considerable. through the caput available is normally low and capable to the tail H2O conditions. Occasionally. high caput workss may besides belong to this class. like for illustration. a dike constructed for pilotage or irrigationpurposes at the caput of a H2O autumn. making practically no pondage. Therefore. the power house located at the toe of the autumn will be a “high caput run-of-river works. ” The well known Niagara Falls works is a good illustration of this type.
The capacity of the tally of river works without pondage is fixed matching to the lower limit flow available in the watercourse. Thus it is strictly a base burden works with a high burden factor ( 90-100 % ) . In tally of river workss. the dominant characteristic is that the normal tally or flow of the river is non materially disturbed due to the building of the works. Such workss neither have a big reservoir nor do they hold a recreation of the H2O off from the chief channel. The power house is located along the chief class of the river. Such workss are rather popular in Europe and all major rivers have a series of such workss along their class. In India on the other manus. really few classical run-of-river workss are constructed. The workss which come cupboard to be described as run-of-river workss are Obra ( U. P. ) . Jawaharlal Sagar ( Rajasthan ) etc. A ground for the non handiness ofrun of river workss in India is its typical monsoon clime which brings about the building of flow merely in a few months. European rivers. on the other manus have a more or less uniformly distributed flow a demand eminently suited for this class of hydel workss.
2. 4. 3Run of river workss with pondage.
Pondage normally refers to the aggregation of H2O behind a dike near the works. and increases the watercourse capacity for short periods. storage means aggregation of H2O in reservoirs upstreams of the works and this increases the capacity of the watercourse over an drawn-out period of several months. Storage workss may work satisfactorily as base burden and peak burden Stationss. Some tally of river workss have pondage installation available. which enables them to hive away H2O during off peak period and utilize it during the peak hours of the same twenty-four hours or hebdomad. Thus the works has the flexibleness to run into the hourly or day-to-day fluctuations. The works discharge may therefore be many times more ( 3 to 8 times ) than the minimal watercourse flow. Pondage increases the watercourse capacity for a short period. hours or hebdomad depending upon the capacity of the pool. This works can be used as base burden or peak burden workss. Run-of-river workss are usually basal burden workss. but with some pondage available they may be able to run both as extremum burden every bit good as base burden workss. depending upon the flow available in the river. When a batch of flow is available in the river. they operate on the base of the 10ad curve. However with reduced watercourse flow. they may practicably run on the extremum of the burden curve.
2. 4. 4Storage workss ( Reservoir workss ) .
in such workss. have reservoirs of reasonably big size. which normally provide sufficient storage to carryover from moisture season to dry season and sometimes even from one twelvemonth to another. They can therefore supply H2O at a changeless rate which is substantiallY higher than the minimal natural flow of the watercourse. The large dikes. making big lakes. normally provide comparatively high caputs for these power workss. The advantage of this works is that the power generated by the works during dry season will non be aff~cted. The storage takes attention of fluctuations of the river supply or that of the burden. In valley dike workss. a dike is dominant characteristic. making a storage reservoir. Power house is located at the toe of the dike. No recreation of H2O off from the river is involved. The storage reservoir develops the necessary caput for the power house. Water flows through sluicegates embedded in the dike to the power house and joins the chief Rhode Island ver class straight at the mercantile establishment of the power house. The vale dike workss are of medium to high caputs. The artifidal caput created will depend in the tallness of the dike. Main parts of a vale dike pi emmet are: 1. The dike with its accoutrements like wasteweirs etc.
2. The consumption with rubbish racks. halt logs. gate and ancillaries. 3. The sluicegates conveying H2O to the turbines with recess valves and anchorages. 4. The chief power house with its constituents.
2. 4. 5Pumped Storage Plants.
This type of works in combination with hydro-electric power works is used for providing. the sudden extremum burden for short duration–a few hours in the twelvemonth. These are particular type of power workss which work as ordinary conventional hydropower Stationss for portion of the clip. The forte of these power workss lies in the fact that when such workss are non bring forthing power. they can be used as pumping Stationss which pump H2O from the tail race siJe to the high degree reservoir. At such times these power Stationss utilise power available from elsewhere to run the pumping units. The working of the power Stationss can be distinguished as the bring forthing stage when the turbines and generators are bring forthing electrical power and the pumping stage when the pm”1ps and motors are in operation. During the bring forthing stage. hence. H2O flows from the high degree into the power house and thence to the tailrace side in the pumping stage it is frailty versa.
This basic agreement is schematically shown The cardinal agreement consists in holding two pools. one at a high degree and the other at a low pool with the power house busying an intermediate station. The H2O transitions are from the higher degree pool to the power house and so from the power house to the lower pool. which carry H2O in either way depending upon the generating or the pumping stage. Figure shows the high height reservoir. the sluicegates. the power house ( incorporating reversible pump turbine and motor-generating units etc. ) and the tail H2O pool of a typical such strategy. The taiIwater may some times be a perennial ( enduring through the twelvemonth ) river. or a natural lake. The capacity of the upper pool should be adequate to run into atleast four to six hours of peak demand at the available caput. Greater the available caput. smaller the capacity of pool required for the given end product.
2. 5Classification Based on Head
Most popular and conventional categorization happens to be the one based on caput. Types of works
1- Low caput workss less than 30 metres
2- Medium caput workss 30 to 100 metres
3- High caput workss Head above 100 metres.
2. 5. 1Low caput workss
When the operating caput is less than 30 metres. the works is known as low caput works. These are besides known as canal power workss. These are of two types which are run of river workss and recreation canal type A low caput ( canal H2O power works ) type is one type of works. It shops H2O by the building of a dike across a river and the power works is installed near the base of the dike on the downstream side. The tailrace of the turbines is joined to the river on the downstream side. In this instance no rush armored combat vehicle is required. as the power house is located near the dike itself and the dike is designed to take the force per unit area created due to the back flow under load conditions. This type of works uses perpendicular shaft or Kaplan turbine.
2. 5. 2Medium caput workss
The medium caput works is similar to the low caput works but works on a caput of approximately 30 to 100 m. This type of works utilizations Francis. propellor or kaplan turbine as premier mover. The forebay provided at the beginning of pen-stock serves as H2O reservoir. The forebaydraws H2O from chief reservoir through a canal or tunnel. Forebay besides shops the rejected H2O when so burden on the turbine decreases. The Forebay itself works as a rush armored combat vehicle in the works.
2. 5. 3High caput workss
In the high caput workss H2O is stored at high lifts due to rain etc. and can normally last throughout the twelvemonth. the lift of a high caput works. The chief parts of such a works are the dike. the consumption or caput plants. the force per unit area tunnel. the rush armored combat vehicle. the pen stock. the power house and the tailrace
. At one terminal of the reservoir are provided mercantile establishments for H2O taking into forebays or rush armored combat vehicles and from at that place to the turbines through sluicegates. Rubbish racks are fitted at the recesss of the force per unit area tunnels to forestall the foreign affair from traveling into the tunnels. Since the tunnel carries the entire caput matching to existent reservoir degree. the pick of the force per unit area tunnel should be given a really careful consideration. A force per unit area tunnel can be replaced either by a canal.
2. 6Selection of Site for Hydro-electric Power Plant
While choosing a suited site. if a good system of natural storage lakes at high heights and with big catchment countries can be located. the works will be relatively economical. The indispensable features for a good site are big catchment country. steep gradient to the country. high mean rain autumn and favorable sites for attaching reservoir. For this intent. the geological. geographical. and meterological conditions of a site. necessitate to be carefully investigated.
The most of import factors which have to be considered in this choice are
1. Measure of H2O available.
2. Storage of H2O.
3. Head of H2O which can be utilized.
4. Distance of power station site from power demand centres or burden Centre.
5. Handiness of the site.
2. 7Spillways
A spillway Acts of the Apostless as a safety valve for a dike. Spillwaies and Gatess help in the transition of inundation H2O without any harm to the dike. They keep the reservoir degree below the preset maximal degree. Whatever may be the type of dike. it is perfectly necessary to supply a safe transition for the inundation H2O down watercourse. so as to avoid the danger of the dike being over topped. The portion of the dike which discharges the inundation flow to the down stream side is called as ‘spillway’ . The wasteweir does non get down dispatching this the H2O reaches a preset degree. called the Full R~serv ( ) ir Level ( FRI. ) . The highest degree up to which the H2O is allowed to lift in the reservoir even during high inundations is called as Maximum Water Level ( MWL ) . The difference between MWL and FRL is called as the inundation lift. The reservoir degree will ne’er traverse MWL. at this degree the dispatching capacity of the wasteweir has to be such that the over flow over the wasteweir is at least equal to the instantaneous influx. The wasteweir is an of import portion of the dike composite and is located either as a portion of the chief dike or separated at a suited topographic point near the dike.
2. 7. 1Types of Spillwaies
Depending upon the location of the site there are assorted types of wasteweirs which may be appropriately provided under prevalent fortunes. These can be listed as:
1. Over flow wasteweir
2. Parachute or trough wasteweir
3. Side channel wasteweir
4. Shaft wasteweir
5. Siphon spillway’ .
2. 7. 1. 1Over flow wasteweir ( Ogee spillway ) .
An over flow wasteweir may hold a control device. called a gate on the top of the crest or it may be without any such control. For an ungated wasteweir. the crest degree forms the FRL and the tallness of the inundation lift added over the crest degree ( FRL ) corresponds to MWL as shown in Fig. 11•7•6. However. when the wasteweir is gated. the Gatess provide an extra storage up to their crests ( top ) during off-flood season.
2. 7. 1. 2Chute or Trough wasteweir.
The type of wasteweir is provided through the abutments of the dike when it is non possible to go through inundations over the dike as in the instance of earthern and stone fiU dike. The discharging H2O flows into a steep sloped unfastened channel called chute. The channel is made of strengthened concrete slabs. The crest is normally broad and so the channel narrows for economic system. The terminal is so once more flared or widened for cut downing the speed. This type of wasteweir is suited for Earth dikes because it is light. The chute wasteweirs are simple in design and building and are adoptable to almos: all foundation conditions.
2. 7. 1. 3Side channel wasteweirs.
In a narrow vale. where the needed crests length of the overflow wasteweir is non available. or. in a less broad watercourse where it is advantageous to go forth the control part of the watercourse for the power house. the side channel wasteweir is convenient. In this type. the flow being carried over the crest passes in a channel about parallel to the crest. It implies. therefore. that the side channel wasteweirs are applicable to narrow gorges. Another state of affairs where side channel wasteweirs can be given serious consideration is in the instance of embankment dikes. The design consideration~ require the side channels of sufficient capacity. so as to able to transport the maximal inundation discharge without submersing the weir crest to an extended that the weir discharge capacity is restricted~The side channels are largely of trapezoidal subdivision.
2. 7. 1. 4Shaft wasteweir.
The shaft wasteweir. besides some times known as ‘morning glory’ wasteweir has form of perpendicular funnel with a perpendicular through the dike or through the abutments conveying H2O past the dike. In a shaft wasteweir. the H2O drops through the perpendicular shaft and passes through a horizontal conduit go throughing through the dike at the underside which conveys the H2O to the downward site of the damshaft which connects an L-shaped horizontal mercantile establishment behavior. widening. The shaft wasteweir is suited for narrow gorges where other types of wasteweirs do non happen equal infinite. In earthen dikes where even a side channel or jump wasteweir is unsuitable for privation of infinite. a shaft wasteweir may be excavated through the foundation or wings of the river vale. The drawback of this wasteweir is the jeopardy of choke offing with debries. Therefore. rubbish racks. drifting roars and other protection debries should be used to forestall the debries from come ining the wasteweir recess.
2. 7. 1. 5Siphon wasteweirs
The rule of operation of a syphon wasteweir is based on siphonic action. Such a wasteweir occupies less infinite and regulates the reservoir degree with narrow bounds. With this belongings. the syphon wasteweir besides finds its usage in canal foreway where the rushs created by the alteration in turbine tonss are to be equalised. It will be observed that ab initio the reservoir degree is upto the crest of the wasteweir. A sheet of H2O starts going over the crest. if there is rise in H2O degree of the reservoir due to deluge. When all the air entrapped within the goon is drawn out and infinite gets filled with H2O ( called primary ) syphon action starts and H2O starts fluxing over the crest.
HYDROPOWER PLANT IN MALAYSIA
3. 0Hydroelectric works in Malaysia
400MW Kenyir Hydropower Station in Terengganu
The history of hydropower dike development in Peninsular Malaysia. The first major dike. the Chenderoh Dam. was constructed in 1939. There followed a long spread before building recommenced after the Second WorldWar. get downing with the Sultan Abu Bakar Dam ( Cameron Highlands ) in 1963. A impermanent letup in building activity occurred between the late sixties and early 70s when fuel oil was still really competitively priced as to offer a feasible thermic option for power coevals. The oil monetary value addition in the mid 70s shifted attending back to hydropower in the overall energy development program. This finally led to the building of four more dikes between 1974 and 1984. These are Temengor ( 1974 ) . Bersia ( 1980 ) . Kenering ( 1980 ) and Kenyir
( 1980 ) .
3. 1Terengganu Hydroelectric Dam 400MW installed capacity
Sultan Mahmud Power Station 4X100MW
3. 2Cameron Highlands Dam 262MW installed capacity
1-Jor Dam 100MW
2-Woh Dam 150MW
3-Odak Dam 4. 2MW
4-Habu Dam 5. 5MW
5-Kampung Raja Dam 0. 8MW
6-Kampung Terla Dam 0. 5MW
7- Robinson Falls Dam 0. 9MW
3. 3Sungai Perak Hydroelectric Dam installed capacity
1-Bersia Dam 72MW
2-Chenderoh Power Station 40. 5MW
3- Kenering Power Station 120MW
4- Sungai Piah upper dike 14. 6MW
5-Sungai Piah lower dike 54MW
6-Temenggor Power Station 348MW
3. 4Future development in Malaya
As for future hydro development in Peninsular Malaysia. several undertakings have been identified and studied at feasibleness and pre-feasibility degrees. These possible undertakings have to vie with alternate energy beginnings such as coal and gas in footings of economicviability. From the economic point of position. it is clear that hydropower requires significant initial investing costs which can be a hindrance to possible developers. It has been proven in some states of the inability of the private sector to set about such investings. However. this should be balanced against the long life and low operating costs of hydro workss. and the fact that there is no ingestion of fuel for energy coevals. Globally. in comparing with other workss. and sing the quality of the energy produced. the balance shows a clear advantage for hydropower. At the 17th Congress of the World Energy Council in 1998. it was concluded that clear precedence should be given to the development and usage of appropriate renewable energies with the purpose of restricting emanations ensuing from the usage of fossil fuels.
Discussion
4. 0Advantages of hydroelectric
•Does non depend on costs of U. oil. or other fuels
•Pollution is seldom created
•It doesn’t require as many employees
•It can be set up in many sizes
•Stations can run and run for long periods of clip
•Reduces greenhouse emanations
•Relatively low care costs
•Can be used throughout the universe
•It is renewable
•Hydroelectricity produces no gas emanations or waste.
•Hydroelectric Stationss are cheap to run.
•Makes hardly any pollution comparison to other ways of making electricity
•Hydroelectric power is one of the most antiphonal ( easy to get down and halt ) of any electric power bring forthing beginning.
•The transition of the forces of H2O to electric energy can be up to 90 per centum efficient.
•Hydroelectric power produces no chemical or waste heat pollution.
•Hydroelectric power workss require small care.
•Reservoir lakes can be used for diversion. and can supply considerable inundation protection to downstream countries. •Groundwater militias are increased by reloading from reservoirs. •Plants normally have an expected life span two to three times longer than conventional thermic power workss. •Hydroelectric installings can be used to engender fish and other aquatic merchandises •It is more dependable than solar and wind power – because H2O can be stored and there is more of it. more frequently. Once a dike is constructed. electricity can be produced at a changeless rate. •If electricity is non needed. the penstock Gatess can be shut. halting electricity coevals.
The H2O can be saved for usage another clip when electricity demand is high. The physique up of H2O in the lake means that energy can be stored until needed. when the H2O is released to bring forth electricity. •Dams are designed to last many decennaries and so can lend to the coevals of electricity for many old ages / decennaries. •The lake that signifiers behind the dike can be used for H2O athleticss and leisure / pleasance activities. Often big dikes become tourist attractive forces in their ain right. •The lake’s H2O can be used for irrigation intents.
•When in usage. electricity produced by dike systems do non bring forth green house gases. They do non foul the ambiance. •Hydropower is a fueled by H2O. so it’s a clean fuel beginning. Hydropower doesn’t pollute the air like power workss that burn fossil fuels. such as coal. oil or natural gas. •Hydropower is a domestic beginning of energy. produced locally near where it is needed. •Hydropower relies on the H2O rhythm. which is driven by the Sun. therefore it’s a renewable power beginning so long as the rain keeps falling on the dike catchment country. •Hydropower is by and large available as needed ; applied scientists can command the flow of H2O through the turbines to bring forth electricity on demand. •Hydropower is non merely a cleaner beginning of energy than oil but is it more cost effectual as good. The most efficient coal combustion workss are merely able to change over around 50 per centum of their energy into electricity. whereas modern twenty-four hours hydro power turbines convert up to 90 per centum of their energy into electricity.
•Hydropower can be less than a penny per kWh ( Kilowatt Hour ) compared to fossil fuel power workss at about 2 to 3 cents per kWh. That may non look like a large difference. but when factored out over a twelvemonth and the 1000000s of kilowatt hours Americans burn. it adds up to a immense nest egg. •Hydropower workss besides have an added fillip as they create recreational chances for people every bit good as electricity. Hydro power dikes provide non merely water-based activities. but since much of the environing land is public they besides encourage legion other out-of-door activities aside from boating. skiing. fishing. and runing. •Hydropower workss provide benefits in add-on to clean electricity. Hydro power workss create reservoirs that offer a assortment of recreational chances. notably angling. swimming. and boating. Most hydro power installings are required to supply some public entree to the reservoir to let the populace to take advantage of these chances. Other benefits may include H2O supply and inundation control. •Can aid modulate river flows ( flood bar ) . shops H2O. creates recreational lake ( though these utilizations frequently conflict ) .
4. 1Disadvantages of hydroelectric
•High investing costs
•Dependent on precipitation
•Sometimes messes up wildlife
•Loss of fish species
•Change in river or watercourse quality
•Cost for building
•Hydroelectric power production require implosion therapy of full vales and scenic countries. •Disrupts natural seasonal alterations in he river. and ecosystems can be destroyed. •Ends deluging that aid to clean out the silt in rivers. doing them to choke off ( Energy Laboratory ) . •The silt that normally flows down to the Beaches and Estuaries is block by the dike. •Studies show that the works decay caused downstream of major dikes produces as many nursery gasses as more conventional methods of bring forthing electricity. •Dams are expensive to construct. and due to drought may go useless. or bring forth much less power than originally planned. •A dike being build in Quebec will stop up deluging an country every bit big as Switzerland ( Energy Laboratory ) . •Dams can interrupt in a monolithic flash inundation
•Construction costs of large-scale hydroelectric undertakings are high. •Damming rivers causes alterations in ecological rhythms and environing landscapes ; self-acting ecosystems are changed into 1s that must be managed. •Sedimentation can increasingly restrict a dam’s ability to hive away H2O and generate energy. •There are a limited figure of executable sites for big dikes. •Damming can do loss of land suited for agribusiness and diversion. •Drought can impact power production.
•Dams are vulnerable to natural forces. There is a high direct decease rate from the failure of dike. •River channels downstream from dikes are more susceptible to eroding. •A disadvantage of hydroelectric power Stationss is that it destroys wildlife and home grounds of any animals populating in the country. •Dams are highly expensive to construct and must be built to a really high criterion. •The high cost of dam building means that they must run for many decennaries to go profitable. •The implosion therapy of big countries of land agencies that the natural environment is destroyed. •People life in small towns and towns that are in the vale to be flooded. must travel out. This means that they lose their farms and concerns. In some states. people are forcibly removed so that hydro-power strategies can travel in front. •The edifice of big dikes can do serious geological harm. For illustration. the edifice of the Hoover Dam in the USA triggered a figure of earth temblors and has depressed the earth’s surface at its location. •Although modern planning and design of dike is good. in the past old dikes have been known to be breached ( the dike gives under the weight of H2O in the lake ) .
This has led to deceases and deluging. •Dams built barricading the advancement of a river in one state normally means that the H2O supply from the same river in the undermentioned state is out of their control. This can take to serious jobs between neighbouring states. •Building a big dike alters the natural H2O table degree. For illustration. the edifice of the Aswan Dam in Egypt has altered the degree of the H2O tabular array. This is easy prima to damage of many of its ancient memorials as salts and destructive minerals are deposited in the rock work from ‘rising damp’ caused by the altering H2O table degree. •Hydro power dikes can damage the surrounding environment and change the quality of the H2O by making low dissolved O degrees. which impacts fish and the environing ecosystems. They besides take up a great trade of infinite and can enforce on animate being. works. and even human environments. •Fish populations can be impacted if fish can non migrate upstream yesteryear impounding dike to engendering evidences or if they can non migrate downstream to the ocean.
Upstream fish transition can be aided utilizing fish ladders or lifts. or by pin downing and haling the fish upstream by truck. Downstream fish transition is aided by deviating fish from turbine consumptions utilizing screens or racks or even submerged visible radiations and sounds. and by keeping a lower limit spill flux past the turbine. •Hydro power can impact H2O quality and flow. Hydro power workss can do low dissolved O degrees in the H2O. a job that is harmful to riparian ( riverside ) home grounds and is addressed utilizing assorted aeration techniques. which oxygenate the H2O. Keeping minimal flows of H2O downstream of a hydro power installing is besides critical for the endurance of riparian home grounds. •Hydro power workss can be impacted by drouth. When H2O is non available. the hydro power workss can’t produce electricity. •New hydro power installations impact the local environment and may vie with other utilizations for the land. Those alternate utilizations may be more extremely valued than electricity coevals.
Worlds. vegetation. and zoology may lose their natural home ground. Local civilizations and historical sites may be flooded. Some older hydro power installations may hold historic value. so redevelopments of these installations must besides be sensitive to such saving concerns and to impacts on works and carnal life. •By 2020. it is projected that the per centum of power obtained from hydro power dikes will diminish to around four per centum because no new workss are in the plants. and because more money is being invested in other alternate energy beginnings such as solar power and air current power. •Dams normally flood big river vale. covering a batch of native home ground with H2O. displacing animate beings and sometimes people. In China more than one million people were moved when they built their large “Three Gorges” dike. Many archeological sites are now unapproachable under H2O and there is environmental harm along the Bankss of the many feeders of the Yangtze Rive.
