1. MALDIVES POWER
STATION IN FUTER
MAKE ELECITEY IN SEA WATER IN MALDIVES
MODEL TECONOLEY USING IM MALDIVES IN 2016
2.
3. EVERY ATOLL ONE THAMES BARRIER MAKE SEA WATER ELETRICITY MAKE A BACKUP WATER
PLANTE INALL AREA OFMALDIVES
Thames Barrier
he Thames Barrier is located downstream of central London. Operational since 1982, its
purpose is to prevent thefloodplain of allbut the easternmost boroughs of Greater London
from being flooded by exceptionally high tides and storm surges moving up from the North
Sea. When needed, it is closed (raised) during high tide; at lowtide it can be opened to
restore the river'sflow towardsthe sea. Built approximately 3 km (1.9 mi) due east of the
Isle of Dogs, its northern bankis inSilvertown in the London Borough of Newham and its
southern bank is in the New Charlton area of the RoyalBorough of Greenwich. The report
of Sir Hermann Bondi on the North Sea flood of 1953 affecting parts of the ThamesEstuary
and parts of London[1] was instrumental in the building of the barrier
History
Design andconstruction
The conceptof the rotating gates wasdevised by (Reginald) CharlesDraper. In the 1950s, fromhis
parents' house inPellatt Grove,WoodGreen, London,he constructed a workingmodel. The novel
rotatingcylinderswere based on a small householdappliance –a brassgas tap whichcould be found
in mostpost-warhouses inthe UK. The barrier was designedby Rendel, Palmer andTritton for the
Greater LondonCouncil andtested at the HydraulicsResearch Station,Wallingford.Thesite at New
Charltonwas chosenbecause of the relative straightnessofthe banks,andbecause the underlying
river chalk was strongenoughto supportthe barrier. Work beganat the barrier site in 1974 and
construction,whichhad been undertakenby a Costain/HollandscheBetonMaatschappij/Tarmac
Constructionconsortium,[3]waslargelycomplete by 1982. The gates of the barrier were made by
ClevelandBridge UK Ltd[4] at Dent's Wharfon the River Tees.[5]
4. In additiontothe barrier, the flooddefences for 11 milesdown river were raisedand strengthened.
The barrier wasofficiallyopenedon8 May 1984 by Queen ElizabethII. Total constructioncost was
around£534 million(£1.3 billionat2001 prices) with anadditional £100 millionforriver defences.
Built acrossa 520-metre (570 yd) widestretch ofthe river, the barrier dividesthe river intofour 61-
metre (200 ft) andtwo, approximately30 metre (100 ft) navigablespans.There are alsofoursmaller
non-navigablechannelsbetweennineconcrete piersand two abutments.The floodgatesacross the
openingsare circularsegments in cross section,andthey operate by rotating,raisedto allow
"underspill" toallowoperatorsto control upstream levels anda complete 180 degree rotationfor
maintenance.All the gates are hollowandmade of steel up to 40 millimetres(1.6 in) thick.The gates
are filledwith water when submerged andempty as they emerge from the river. The fourlarge central
gates are 20.1 metres (66 ft) highand weigh3,700 tonnes.[6]Four radial gates by the riverbanks,also
about30 metres (100 ft) wide, canbe lowered.These gate openings,unlikethe mainsix, are non-
navigable.
Predictionsfor operation
A Thames Barrier flooddefence closureis triggered when a combinationofhightidesforecast in the
North Sea andhighriver flowsat the tidal limitat Teddingtonweir indicatethat water levels would
exceed 4.87 metres (16.0 ft) in central London.ThoughTeddingtonmarks the Normal Tidal Limit,in
periodsof very high fluvial flowthetidal influencecan be seen as farupstream as East Molesey,
locationofthe secondlock[clarificationneeded]onthe Thames.[7][8] Forecast sea levelsat the mouth
of the Thames Estuary are generated by Met Officecomputers andalsoby models run onthe Thames
Barrier's own forecastingandtelemetry computer systems. About9 hours before the hightide reaches
the barrier a flooddefenceclosure beginswith messagesto stop river traffic,close subsidiarygates
and alert other river users. As well as the Thames Barrier, the smallergates alongthe Thames Tideway
includeBarking Barrier, KingGeorge V Lock gate, Dartford Barrier andgates at Tilbury Docks and
CanveyIsland must alsobe closed. Once river navigationhasbeen stoppedand all subsidiarygates
closed,then the Thames Barrier itselfcan be closed. The smaller gatesare closedfirst, then the main
navigablespansinsuccession.The gates remain closeduntil the tide downstreamof the barrier falls
to the same level as the water level upstream.
After periods ofheavy rain west of London,floodwatercanalso flowdownthe Thames fromareas
upstream ofLondon.Because the river is tidal from Teddingtonweir all the way throughLondon,this
is onlya problemat hightide,which prevents the floodwaterfrom escapingout to sea. From
Teddingtonthe river isopeningout into itsestuary, and at lowtide it can take muchgreater flowrates
the further one goes downstream.In periods when the river is in floodupstream,ifthe gates are
closedshortly after low tide,a huge empty volumeis created behindthe barrier which canact asa
reservoir to hold the floodwatercomingover Teddingtonweir. Most river floodswill not fill this
volumein the few hours of the hightide cycle duringwhich the barrier needs to be closed. If the
barrier were not there, the hightide wouldfill upthis volumeinstead,and the floodwatercouldthen
spill over the river banksin London.Abouta third of the closures upto 2009 were to alleviatefluvial
flooding.
5. Barrier closuresand incidents
During the barrier'sentire historyup to July2014, there have been 174 flooddefenceclosures. It costs
£16,000 (2008) to close the Thames Barrier oneach occasion.[10]The barrier was closedtwice on9
November 2007 after a storm surge inthe North Sea whichwas comparedto the one in1953.[11] The
maindanger of floodingfromthesurge was on the coast above the Thames Barrier, where
evacuationstook place,but the windsabated a little and,at the Thames Barrier, the 9 November2007
storm surge didnot completelycoincidewith hightide.[12]
On 20 August1989, hours after the Marchionessdisaster,the barrier wasclosed againsta springtide
for 16 hours "toassistthe divingandsalvageoperations".[13]
On 27 October 1997, the barrier was damagedwhen the dredger MV SandKite, operatingin thick fog,
collidedwithone of the Thames Barrier's piers. As the shipstarted to sinkshe dumpedher 3,300 tonne
loadof aggregate,finallysinkingbythe bow on top of one ofthe barrier'sgates where she lay for
several days.Initiallythe gate couldnot be closed as it wascovered ina thick layer of gravel.A longer
term problemwas the premature lossof painton the flat side ofthe gate causedby abrasion.One
estimate of the cost of floodingdamage,haditoccurred, was around£13 billion.[14]Thevessel was
refloatedin mid-November1997.
The annual full test closurein 2012 was scheduledfor 3 June to coincidewith the Thames pageant
celebratingQueen ElizabethII's DiamondJubilee.Floodrisk managerAndy Batchelor saidthe pageant
gave the EnvironmentAgency "a uniqueopportunityto test its designfor a longerperiod than we
wouldnormallybe able to",and that the more stable tidal conditionsincentral London that resulted
wouldhelp the vessels takingpart.[15]
The barrier hassurvived 15 boatcollisionswithoutseriousdamage
6. History
The Company emerged from modest beginnings in 1949 with an installed
capacity of only 14 kW and providing electricity to just the residences in
Male’.
Over the past five decades the Company operated as a Government
Department under different names like “Department of Electricity” and
“Maldives Electricity Board” until 1997, when “State Electric Company”,
STELCO, was formed.
Initially the number of customers were 50 houses in Male’. Today the total
number of customers have increased to 26,055 in Male’ and 20,503
customers in the islands (as at March 2009). Thus, STELCO now provide
electricity to over 46% of the total population.
Welcome
7. State Electric Company Ltd, STELCO, is wholly owned by the Government of
Maldives. Our core business includes power generation, distribution and
retail.
We operate 27 power system in 27 islands, providing electricity to 43% of
the population of the country. Each power system is independent with its
own power generation and distribution infrastructure.
STELCO has its largest operation in Male’, the capital of Maldives, with an
installed capacity of 61.42MW, and a 26 km underground 11kV distribution
network feeding power to 99 distribution transformers to provide
electricity to 33,341 customers.
Marine gas oil is the only fuel used for power generation and exhaust heat
from the power station is used by an ME desalination plant with a daily
production capacity of 150 tones per day to produce water for Male’ power
station’s use.
Today STELCO has an installed capacity of 79.2MW, 471 employees and a
customer base of 41,743 (as at August 2012).
Malé
The Malé powerhouse is the largest generation facility in Maldives. We
generate and provide reliable and efficient electric energy to meet the
growing demand of Malé.
A 56 member staff team, with engineers, supervisors, and technicians keep
the power facility in operating condition at all times.
HOW TO MAKE ELETRICITY IN SEA WATER IN UK
MALDIVES ALSO MAKE ELETRICITY IN SEA WATER SAME
AS UK
8. WATER FROM THE OCEAN OR THE SEA IS AVIABLE BY DIGGING ACANALFROM THE OCEAN WATER
SURFACEAND GOING DEEP INTOTHE EARTH BY DIGGING 100 METERS BELOW THE SEA LEVEL AND
THEN CONNECTING THISCANAL INTO A HEAD RACE TUNNEL 100 METERS BELOW THE EARTH.FROM
HERE THE UNDERGROUNDDAMS WILL START IN THE STAITCASE MODEL AND WILL GODEEP I.E. 2100
METERS ,INTO THE EARTH TO FORM STEPS ONE STEP STARTS WHERE THE OTHER ENDS AND ON EACH
INDIVIDUAL STEP THERE WILL BE INDIVIDUAL DAMS TO GENERATE ELECTRICITY AND WHENTHE LAST
STEP IS CONSTRUCTED THE BASE RESERVOIR STARTS BELOW THE LAST STEP AND THE WATER
RUNNING DOWNTHE HILL AFTER SPINNING THE TURBINES WILL BE COLLECTED INTO THIS RESERVOIR
. WATER PUMPS WILL BE USED TO LIFT THIS WATER FROM A DEPTH OF 2100 METERS DEEP BELOW
THE EARTH IN STEP WISE ONLYAND HERE IN EACH STEP , THE STEP IS DIVIDED INTO 3 CHAMBERS .THE
FIRST CHAMBER WILL HOLD THE PUMPEDWATER ,THE SECOND CHAMBER WILLHAVE A HYDRO
TURBINE AND THE THIRD CHAMBER WILL HOLD THE WATER COMMING OUTOF THE TURBINE SO
THAT THE WATER PUMPSCAN LIFT THIS WATER TO THE NEXT STEP THIS STEPS ARE ALSO IN THE
STAIRCASE MODEL.THE EARTH WHICH IS REMOVED TO DIG THE STEPS WILL BE USED TO CONSTRUCTA
BIG MOUNTAINAND ON THIS MOUNTAINTOO THERE WILL BE DAMS .THE WATER IS PUMPED INTO
THE DAMS FROM THE SURFACEOF THE FINAL STEP AND WATER IS COLLECTED INTO A RESERVOIR
CONSTRUCTED ONTOP OFTHE MOUNTAINAND WATER IS RELEASED INTO THE DAMS FOR THE SEA
WATER ELECTRICAL GENERATION.AS THE WATER IS COMMING DOWNTHE MOUNTAINTHIS WATER
IS COLLECTED INTO A CANALAND THIS CANAL IS CONNECTEDONCE AGAININTOTHE OCEAN.THIS IS A
CIRCUITAND A FACILITYIN WHICH SEA WATER WILL CIRCULATE IN THE ENTIRE FACILITY AND THERE IS
ELECTRICAL GENERATIONIN THE ENTIRE FACILITY.IN ALL THE STEPS SEA WATER WILL FALL IN A
WATER FALL TO GET THE REQUIRED DRAG INTO THE TURBINE I.E. 6000000/- LAC LITERS OF SEA
WATER PER EVERY INDIVIDUALSECOND FROM A HEIGHT OF 100 METERS DIRECTLY INTO THE 1000
MEGAWATTTURBINE-GENERATOR . THE RAW MATERIAL IS AVIALABLE IN PLENTY AND IT IS FREE OF
COST TO GENERATE CHEEP SEA WATER ELECTRICITY.24X7=366 DAYS THE GENERATION IS EVER GREEN.
IN THIS INVENTIONWE CAN DESIGN THE SEA WATER ELECTRICITY FACILITY ACCORDING TO OUR
9. REQUIREMENTS AND FINANCEAVIALABLE WECAN GENERATE FROM FEW WATTSTO ANYNUMBER
OF MW , EITHER SMALL OR BIG GENERATIONSANY WHERE ON THE GLOBE BECAUSE IN THIS FACILITY
THE HEAD AND WATER VELOCITY WILL BE CONSTANT AND THE WATER IN THE OCEANIS EVER GREEN
CSR SYSTEMS IS A COMPANYDEDICATED TO THE OCEANHYDRO ELECTRICAL GENERATION BY
DESIGNING CHEAPAND ECONOMICALGENERATION FACILITIESTO GENERATE OCEANPOWER
GENERATIONSUTIBLE TO ANY PART OF THE WORLD IN A SCIENTEFICAND INNOVATIVEWAYSO THAT
THE GENERATED ELECTRICITY CANBE CONNECTEDTO THE GRID WITH IN A VERY SHORT PERIOD OF
TIME.CSR SYSTEMS MAINOBJECT IS TO ERIDICATE POVERTY BY GIVING CHEAPELECTRICITY TO ALL
PEOPLE AND FOR THE HUMAN UPLIFTMENT SO THAT THER WILL BE ALL ROUND DEVELOPMENT IN
EVERY SECTOR I.E.INDUSTRY, AGRICULTURE,ETC.
Flowing salt water over graphene generates electricity
10. An image of graphene, showing defects in its single-atom thickness
Hydroelectricity isone of the oldest techniquesfor generatingelectrical power, withover 150
countriesusingit as a source for renewable energy. Hydroelectric generators onlywork efficientlyat
large scales,though—scaleslargeenoughto interrupt river flowand possiblyharmlocal ecosystems.
And gettingthis sort of generationdownto where it can power small devices isn'trealistic.
In recent years, scientistshave investigatedgeneratingelectrical power usingnano-structures.In
particular,they have lookedat generating electricity when ionicfluids—aliquidwithchargedionsin
it—arepushed througha system with a pressure gradient.However, the ability to harvest the
generated electricity has been limitedbecause it requires a pressure gradientto drive ionicfluid
througha small tube. But scientistshavenow foundthat draggingsmall dropletsof saltwater on
stripsof graphene generates electricity withoutthe need for pressure gradients.
In their study,publishedinNature Nanotechnology,researchersfrom Chinagrew a layer of graphene
and placeda droplet ofsalt water on it. They then draggedthe droplet across the graphene layer at
differentvelocitiesand foundthat the process generated a small voltagedifference.
In additiontobeing the first to demonstrate thiseffect, the scientistsfounda linear relationship
between the velocityand the generated electricity. The faster they draggedthe dropletacross the
graphene strip,the higher the voltage they generated. The scientistsalsofoundthat the voltage
increased whenmultipledroplets ofthe samesize were used at once.
What’sthe mechanismbehindthis?The scientistslookedat the charge distributiononthe sidesof the
droplet when it wassittingstill on graphene,as well as when it was moving.Whenthe droplet was
11. static,the charge redistributedsymmetricallyonboth sides,leavinga net potential difference of zero
between them.
However, when the dropletwas dragged acrossthe graphenestrip, thisdistributionbecame
unbalanced.The scientistsfoundthat electrons are desorbed fromthe grapheneat one end ofthe
droplet andare adsorbedintothe grapheneat another end, whichresults in a largepotential on one
side ofthe dropletand generates a measurablevoltage acrossits length.
The scientiststhen scaledthis technologyupto demonstrate that you can harvestelectricity from it.
They used a droplet made ofcopper chloride andplacedit on a graphene surface. The surface was
tilted to one sideand the droplet was allowedto flowfrom one end to the other under gravity,
resultingin the generationof a measurablevoltage—approximately30mV.
Althoughorders ofmagnitudelower than today’shydroelectricgenerators, these nano-sized
generators can work with small devices,somethingthat hydroelectricsystems can'tdo. And they can
easilybe scaled up,providingthe potential to create large-scalegenerators.
Generating power from salty water: Unique salt allows
energy production to move inland
Productionofenergy fromthe differencebetween saltwater andfresh water ismost convenientnear
the oceans, but now,usingan ammoniumbicarbonatesaltsolution, researcherscan combinebacterial
degradationofwaste water withenergy extracted from the salt-waterfresh-water gradientto
produce power anywhere.
12. Microbial reversedialysistest cell.
Credit:Penn State, Dept of Public Information
Production of energy from the difference between salt water and
fresh water is most convenient near the oceans, but now, using an
ammonium bicarbonate salt solution, Penn State researchers can
combine bacterial degradation of waste water with energy extracted
from the salt-water fresh-water gradient to produce power anywhere.
We are taking two technologies,eachhavinglimitations,andputtingthemtogether," saidBruce E.
Logan,Kappe Professorof Environmental Engineering."Combined,theyovercome the limitationsof
the individual technologies."
The technologiesLoganrefers to are microbial fuel cells(MFC) -- whichuse wastewater andnaturally
occurringbacteria to produce electricity -- and reverse electrodialysis(RED) -- whichproduces
electricity directly fromthe salinitygradientbetween saltyand fresh water. The combinedtechnology
creates a microbial reverse-electrodialysiscell (MRC).The researchers describe MRCs in the March 1
editionof Science Express.
RED stacks extract energy from the ionic differencebetween fresh water andsalt water. A stack
consistsof alternatingionexchangemembranes -- positiveand negative-- with each RED membrane
pair contributingadditivelytothe electrical output. Unfortunately,usingonlyRED stacks to produce
electricity is difficultbecausealarge number of membranesis required when usingwater at the
electrodes, due to the need forwater electrolysis.
Usingexoelectrogenicbacteria -- bacteria foundinwastewater that consumeorganicmaterial and
produce anelectric current -- reduces the number ofstacks needed and increases electric production
by the bacteria.
Logan,working withRolandCusick,graduate student inenvironmental engineering,andpostdoctoral
fellowYounggyKim,placed a RED stack between the electrodes of an MFCto formthe MRC.
13. Whilethe researchers previouslyshowedthat an MRC canwork withnatural seawater, the organic
matter in water will foul the membraneswithout extensiveprecleaning and treatment of the water.
Seawater use restricts MRC operationto coastal areas, butfood waste, domesticwaste andanimal
waste containabout17 gigawattsofpower throughoutthe U.S. One nuclear reactor typically
produces1 gigawatt.
Rather thanrely on seawater, the researchers used ammoniumbicarbonate,anunusual salt.An
ammoniumbicarbonatesolutionworkssimilarlytoseawater in the MRC andwill notfoul the
membranes.The ammoniumbicarbonateisalsoeasilyremoved from the water above110 degrees
Fahrenheit.The ammoniaandcarbondioxidethat make up the salt boil out,and are recaptured and
recombinedfor reuse.
"Wasteheat makes up 7 to 17 percent of energy consumedin industrial processes," saidLogan."There
is alwaysa source ofwaste heat near where this process couldtake place andit usuallygoesunused."
The researchers tested their ammoniumbicarbonateMRCandfoundthat the initial productionof
electricity was greater than that from anMRC usingseawater.
"The bacteria inthe cell quicklyused up all the dissolvedorganicmaterial," saidLogan."Thisisthe
portionof wastewater that is usuallythe mostdifficulttoremove andrequires tricklingfilters,while
the particulateportion whichtook longerfor the bacteriato consume, ismore easily removed."
The researchers tested the MRC onlyin a fill andempty mode, but eventuallya stream of wastewater
wouldbe run through the cell. Accordingto Logan,MRCs can be configuredto produceelectricity or
hydrogen,makingboth withoutcontributingtogreenhouse gases suchas carbon dioxide.The MRC
tested produced 5.6 watts per square meter.
Loganalso saidnot havingto processwastewater wouldsave about60 gigawatts.
Electricity generation
14. Turbo generator
Electricity generation is the process of generatingelectric power from other sources of primaryenergy.
The fundamental principlesofelectricitygenerationwere discoveredduringthe 1820s andearly 1830s
by the British scientistMichael Faraday.His basicmethod is still used today:electricity is generated by
the movement of a loopof wire, or discof copper between the polesof a magnet.[1] For electric
utilities,itis the first process in the delivery ofelectricity to consumers.The other processes, electricity
transmission,distribution,andelectrical power storageand recovery usingpumped-storagemethods
are normallycarried out by the electric power industry.Electricityis most often generated at a power
stationby electromechanical generators,primarilydriven by heat enginesfueled by chemical
combustionor nuclearfissionbutalsoby other meanssuch as the kinetic energy of flowingwaterand
wind.Other energy sources includesolarphotovoltaicsandgeothermal power.
History
Mainarticle: Electrification
Central power stationsbecame economicallypractical withthe developmentof alternatingcurrent
power transmission,usingpowertransformersto transmit power at highvoltageand with lowloss.
Electricity hasbeen generated at central stationssince1882. The first power plantswere run on water
power[2] or coal,[3]and today we rely mainlyon coal,nuclear,natural gas, hydroelectric,wind
generators, andpetroleum, witha small amountfrom solarenergy, tidal power,and geothermal
sources. The use of power-linesandpower-poleshave been significantlyimportantinthedistribution
of electricity.
15. Diagramof an electric powersystem,
generationsystem in black
Methods of generating electricity
There are seven fundamental methodsof directlytransformingother formsof energy into electrical
energy:
Static electricity,from the physical separationandtransport of charge(examples:triboelectric effect
and lightning)
Electromagneticinduction,where an electrical generator, dynamoor alternatortransformskinetic
energy (energy of motion) intoelectricity. Thisis the most used form forgenerating electricity andis
based onFaraday'slaw.It can be experimentedby simplyrotatinga magnet withinclosedloopsof a
conductingmaterial (e.g.copper wire)
Electrochemistry,the direct transformationofchemical energy into electricity,as in a battery, fuel cell
or nerve impulse
Photovoltaiceffect,the transformationoflightinto electrical energy, as in solarcells
Thermoelectric effect, the direct conversionof temperature differencesto electricity, as in
thermocouples,thermopiles,andthermionicconverters.
Piezoelectriceffect, from the mechanical strainof electricallyanisotropicmoleculesor crystals.
Researchers at the US Department of Energy'sLawrence Berkeley National Laboratory(Berkeley Lab)
have developeda piezoelectric generator sufficienttooperate a liquidcrystal displayusingthinfilms
of M13 bacteriophage.[6]
Nucleartransformation,the creationand accelerationof charged particles(examples:betavoltaicsor
alphaparticleemission)
Static electricity wasthe firstform discoveredand investigated,andthe electrostatic generator is still
used even in modern devicessuch as the Van de Graaffgenerator andMHD generators. Charge
carriers are separatedand physicallytransportedto a positionofincreasedelectric potential.Almost
16. all commercial electrical generationis done usingelectromagneticinduction,inwhichmechanical
energy forces an electrical generator to rotate. There are many differentmethods ofdevelopingthe
mechanical energy, includingheatengines,hydro,windand tidal power. The direct conversionof
nuclear potential energy to electricity by beta decay isused only ona small scale. In a full-sizenuclear
power plant,the heat ofa nuclear reaction isused to run a heat engine. Thisdrives a generator, which
converts mechanical energy intoelectricity by magneticinduction.Mostelectric generationis driven
by heat engines.The combustionoffossil fuelssuppliesmostof the heat to these engines,witha
significantfractionfromnuclearfissionandsome fromrenewable sources. The modern steam turbine
(inventedby Sir CharlesParsonsin 1884) currentlygenerates about80% of the electric power in the
world usingavariety of heat sources.
Sources of electricityin France in 2006;[5] nuclearpower was the mainsource.
Turbines
All turbines are driven by a fluidactingas an intermediateenergy carrier. Manyof the heat engines
just mentionedare turbines. Other types of turbinescan be driven by windor fallingwater. Sources
include:
Steam - Water isboiledby-
Nuclearfission
The burningoffossil fuels(coal,natural gas,or petroleum).In hot gas (gasturbine),turbinesare
driven directlyby gases producedby the combustionofnatural gasor oil.Combinedcyclegas turbine
plantsare driven by both steam andnatural gas. They generate power by burningnatural gasin a gas
turbine anduse residual heat to generate additional electricityfromsteam. These plantsoffer
efficiencyof upto 60%.
Renewables. The steam is generated by:
Biomass
17. Solarthermal energy (the sun as the heat source): solarparabolictroughsandsolar power towers
concentrate sunlightto heat a heat transfer fluid,whichisthen used to produce steam.
Geothermal power. Either steam under pressure emerges fromthe groundanddrives a turbine or hot
water evaporates a low boilingliquidtocreate vapor to drive a turbine.
Ocean thermal energy conversion(OTEC):uses the big differencebetween coolerdeep andwarmer
surface oceanwaters to run a heat engine(usuallya turbine).
Other renewable sources:
Large dams suchas Hoover Dam canprovide large amountsofhydroelectric power; it has 2.07 GW
capability.
that is artificiallyproducedinsidethechimneyby heating it withsunlight,andare more properlyseen
as formsof solarthermal energy.
Large dams suchas Three GorgesDam inChinacan providelarge
amountsof hydroelectricpower; it has a 22.5 GW capability
Reciprocating engines
Large dams suchas Hoover Dam canprovide large amountsof
hydroelectric power; it has2.07 GW capability.
Small electricity generators are often powered by reciprocatingenginesburningdiesel,biogasor
natural gas. Diesel enginesare often used for back upgeneration, usuallyatlow voltages.However
most large power gridsalsouse diesel generators,originallyprovidedasemergency back up for a
specificfacilitysuchas a hospital,tofeed power intothe grid duringcertain circumstances.Biogasis
often combustedwhere it isproduced,such as a landfill orwastewater treatment plant,with a
reciprocatingengine or a microturbine,whichis a small gasturbine.
18. A coal-firedpower plantin Laughlin,NevadaU.S.A.Ownersof this plantceased operationsafter
decliningtoinvest in pollutioncontrol equipmenttocomply withpollutionregulations.[7]
A coal-firedpower plantin Laughlin,NevadaU.S.A.Ownersof this
plantceased operationsafter decliningto investin pollutioncontrol equipmentto complywith
pollutionregulations.
Photovoltaic panels
Unlikethe solar heat concentratorsmentioned above,photovoltaicpanelsconvertsunlightdirectly to
electricity. Althoughsunlightisfree and abundant,solarelectricityis still usuallymoreexpensive to
produce thanlarge-scalemechanicallygenerated power due to the cost of the panels.Low-efficiency
siliconsolarcellshave been decreasing incost and multijunctioncellswithcloseto 30% conversion
efficiencyare now commerciallyavailable.Over40% efficiencyhas been demonstratedin
experimental systems.[8] Until recently, photovoltaicsweremost commonlyused inremote sites
where there is no access to a commercial power grid,or asa supplemental electricitysource for
individual homesandbusinesses.Recent advancesin manufacturingefficiencyandphotovoltaic
technology,combinedwithsubsidiesdrivenby environmental concerns,have dramaticallyaccelerated
the deploymentof solarpanels. Installedcapacityisgrowingby 40% per year led by increasesin
Germany,Japan,andthe UnitedStates.
Other generation methods
Variousother technologieshavebeen studiedanddeveloped for power generation.Solid-state
generation(withoutmovingparts) is of particularinterest in portableapplications.Thisareais largely
dominatedby thermoelectric (TE) devices,thoughthermionic(TI) andthermophotovoltaic(TPV)
systems have been developedas well. Typically,TE devices are used at lower temperatures than TI
and TPV systems.Piezoelectric devicesare used for power generationfrom mechanical strain,
particularlyinpower harvesting.Betavoltaicsare anothertype ofsolid-statepower generator which
produceselectricity from radioactivedecay. Fluid-basedmagnetohydrodynamic(MHD) power
generationhas been studiedas a method for extractingelectrical power from nuclearreactors and
alsofrom more conventional fuel combustionsystems.Osmoticpower finallyisanother possibilityat
placeswhere salt andfresh water merges (e.g.deltas, ...) Electrochemical electricity generationis also
importantin portableand mobileapplications.Currently,mostelectrochemical powercomes from
19. closedelectrochemical cells("batteries"),[9]whichare arguablyutilizedmoreas storage systems than
generationsystems; but open electrochemical systems,known as fuel cells,have been undergoinga
great deal of research and developmentinthe lastfew years. Fuel cells canbe used to extract power
either from natural fuelsor fromsynthesizedfuels (mainlyelectrolytichydrogen) andso can be viewed
as either generationsystems or storage systems dependingontheir use.
Windturbinesusuallyprovideelectrical generationin conjunctionwith
other methods ofproducingpower.
Economics of generation and production of electricity
The selectionof electricityproductionmodes andtheir economic viabilityvariesinaccordance with
demandand region.The economicsvary considerablyaroundthe world,resultingin widespread
sellingprices,e.g. the price inVenezuela is3 cents per kWhwhile inDenmark it is40 cents per kWh.
Hydroelectric plants,nuclearpower plants,thermal power plantsand renewable sourceshave their
own prosand cons,and selectionis based uponthe local power requirement and the fluctuationsin
demand.All power gridshave varyingloadson them but the dailyminimumisthe baseload,supplied
by plantswhichrun continuously.Nuclear,coal,oil andgas plantscan supplybaseload.
Thermal energy is economical inareas of highindustrial density,asthe highdemand cannotbe met by
renewable sources. The effect of localizedpollutionisalsominimizedasindustriesareusuallylocated
away fromresidential areas. These plantscanalso withstandvariationinloadandconsumptionby
addingmore unitsor temporarilydecreasing the productionofsome units.Nuclear power plantscan
produce a huge amountofpower from a singleunit. However, recent disastersin Japanhave raised
concerns over the safety of nuclearpower, and the capital cost of nuclearplantsis very high.
Hydroelectric power plantsare locatedin areas where the potential energy fromfallingwater can be
harnessedfor movingturbines andthe generation ofpower. It isnot an economicallyviablesourceof
productionwhere the loadvariestoo much duringthe annual productioncycle andthe abilitytostore
the flow ofwater islimited.
20. Renewable sources other than hydroelectricity(solarpower, windenergy, tidal power, etc.) due to
advancementsin technology,andwith massproduction,their cost ofproductionhascome downand
the energy isnow in manycases cost-comparativewithfossil fuels.Manygovernments aroundthe
world providesubsidiestooffset the higher cost ofany new power production,andto make the
installationofrenewableenergy systems economicallyfeasible.However,their use is frequently
limitedby their intermittent nature. If natural gasprices are below$3 per millionBritishthermal units,
generatingelectricity from natural gas ischeaper than generatingpower by burningcoal
Production
The productionofelectricity in2009 was 20,053TWh. Sources ofelectricity were fossil fuels67%,
renewable energy 16% (mainlyhydroelectric,wind,solarand biomass),andnuclearpower 13%, and
other sources were 3%. The majorityof fossil fuel usagefor the generation ofelectricity was coal and
gas. Oil was 5.5%, as it is the most expensivecommoncommodityused to produce electrical energy.
Ninety-twopercent of renewable energy was hydroelectricfollowedby windat 6% andgeothermal at
1.8%. Solarphotovoltaicwas0.06%, and solarthermal was0.004%. Data are fromOECD 2011-12
Factbook(2009 data)
Source of Electricity (World total year 2008)
- Coal Oil NaturalGasNuclear Renewables other TOTAL
Average electric power (TWh/year) 8,263 1,111 4,301 2,731 3,288 568 20,261
Average electric power (GW) 942.6 126.7 490.7 311.6 375.1 64.8 2311.4
Proportion 41% 5% 21% 13% 16% 3% 100%
Total energy consumedat all power plantsfor the generationof electricity was 4,398,768 ktoe (kilo
ton of oil equivalent) whichwas36% of the total for primaryenergy sources(TPES) of 2008.
Electricity output(gross) was 1,735,579 ktoe (20,185 TWh),efficiencywas 39%, and the balanceof
61% was generated heat. A small part (145,141 ktoe, which was 3% of the inputtotal) of the heat was
utilizedat co-generationheat andpower plants.The in-houseconsumptionofelectricityandpower
transmissionlosseswere 289,681 ktoe. The amount suppliedtothe final consumerwas 1,445,285 ktoe
(16,430 TWh) whichwas 33% of the total energy consumedat power plantsand heat and power co-
generation(CHP) plants.
21. Energy Flow ofPower Plant
Historical results of production of electricity
Production by country
Mainarticle: Worldenergy resources and consumption
See also:Electricity consumption
The UnitedStates haslong been the largest producer andconsumer ofelectricity, with a global share
in 2005 ofat least25%, followedbyChina,Japan,Russia,and India.Asof Jan-2010, total electricity
generationfor the 2 largest generators was asfollows:USA: 3992 billionkWh(3992 TWh) andChina:
3715 billionkWh(3715 TWh).
List of countries with source of electricity 2008
Data source of values(electric power generated) is IEA/OECD.[13]Listed countries are top 20 by
populationortop 20 by GDP (PPP) andSaudi Arabiabased on CIAWorldFactbook 2009.[14]
Composition of Electricity by Resource (TWh per year 2008)
Country'selectricitysector Fossil Fuel Nuclearrank Renewable Bio
other* total rank
24. Saudi ArabiaSaudi Arabia - 116 88 204 12 - - - -
- - - - - - - 204 18
TaiwanTaiwan 125 14 46 186 15 41 11 7.8 - 0.004 -
0.6 - 8.4 21 3.5 238 16
AustraliaAustralia 198 2.8 39 239 10 - - 12 - 0.2
0.004 3.9 - 16 19 2.2 257 15
NetherlandsNetherlands 27 2.1 63 92 21 4.2 15 0.1 -
0.04 - 4.3 - 4.4 27 6.8 108 23
CountryCoal Oil Gas sub
total rank Nuclearrank Hydro Geo
Thermal Solar
PV Solar
Thermal Wind Tide sub
total rank Bio
other Total rank
Cogeneration
Co-generationisthe practice of usingexhaustor extracted steam froma turbine for heatingpurposes,
such asdrying paper,distillingpetroleumina refinery or for buildingheat.Before central power
stationswere widelyintroducedit was commonfor industries,largehotels andcommercial buildings
to generate their ownpower anduse low pressure exhauststeam for heating.[15]This practice carried
on for manyyears after central stationsbecame commonand is still inuse in many industries.
Environmental concerns
Variationsbetween countriesgeneratingelectrical power affect concerns aboutthe environment.In
France only10% of electricity isgenerated fromfossil fuels,the US is higherat 70% and Chinaisat
80%.[13] The cleanlinessofelectricity dependson its source. Mostscientistsagree that emissionsof
pollutantsandgreenhousegases from fossil fuel-basedelectricitygenerationaccountfor a significant
portionof worldgreenhouse gas emissions;inthe UnitedStates, electricity generationaccountsfor
nearly 40% ofemissions,the largestof any source. Transportationemissionsareclose behind,
contributingaboutone-thirdofU.S. productionofcarbon dioxide.[16]In the UnitedStates, fossil fuel
combustionforelectric power generationis responsiblefor65% of all emissionsofsulfurdioxide,the
25. maincomponentof acidrain.[17] Electricity generationis the fourthhighestcombinedsource of NOx,
carbonmonoxide,andparticulate matter in the US.[18] In July2011, the UK parliamenttableda
motionthat "levelsof (carbon) emissionsfromnuclearpower were approximatelythree times lower
per kilowatt hourthan those ofsolar, fourtimes lower than cleancoal and36 times lower than
conventional coal".[19]
Mainarticle: Life-cyclegreenhouse-gasemissionsofenergy sources
Lifecycle greenhouse gas emissions by electricity source.
Technology Description 50th percentile
(g CO2/kWhe)
Hydroelectric reservoir 4
Wind onshore 12
NuclearvariousgenerationII reactor types 16
Biomass various18
Solarthermal parabolictrough 22
Geothermal hot dry rock 45
SolarPV Polycrystalinesilicon 46
Natural gas variouscombinedcycle turbineswithout scrubbing 469
Coal variousgenerator types withoutscrubbing 1001
Water consumption
Most large scalethermoelectric power stationsconsume considerableamountsofwater for cooling
purposesand boilerwater make up - 1 L/kWhfor once through(e.g. river cooling),and1.7 L/kWhfor
coolingtower cooling.[21]Water abstractionforcooling water accounts forabout 40% ofEuropean
total water abstraction,althoughmostofthis water is returned to itssource, albeit slightlywarmer.
Different coolingsystemshave differentconsumptionvs.abstractioncharacteristics.Coolingtowers
withdrawa small amountof water from the environmentandevaporate most of it.Once-through
26. systems withdrawa large amountbut return it to the environmentimmediately,at a higher
temperature.
