每日一练乐加乐2016年寒假fceday23

POWERINGTHEFUTURE

Despitemodernsociety'sheavydependenceonfossilfuelsforenergy,mostpeopleareawarethatthesupplyofthesefuelsisfinite.Asoil,inparticular,becomesmorecostlyanddifficulttofind,researchersarelookingatalternativeenergysources,includingsolar,wind,andevennuclearpower.Butwhichsubstitute-ifany-istherightone?

Solar

Solarpanelscatchenergydirectlyfromthesunandconvertitintoelectricity.

Oneoftheworld'slargestsolarpowerstationsislocatednearLeipzig,Germany,wheremorethan33,000solarpanelshavethecapacitytogenerateenoughenergytopowerabout1,800homes.Butunliketheburningoffossilfuels,theprocessusedtocreateallthatsolarenergyproducesnoemissions.

Today,however,solarpowerprovideslessthanonepercentoftheworld'senergy,primarilybecausethecostofthepanelsisstillveryhigh.Andpriceisonlyoneissue.Cloudsanddarknessalsocausesolarpanelstoproducelessenergy,whichrequiresonetohaveadditionalpowersources(suchasbatteries)available.

Somescientiststhinkthesolutiontothisproblemcanbefoundinspace-whichtheysayistheidealplacetogatherenergyfromthesun.Withnocloudsandnonighttime,aspace-basedsolarpowerstationcouldoperateconstantly.ThesestationswouldsendthepowerbacktoEarth,whichcouldthenbeturnedintoelectricityforconsumption.

Advocatesofsolarspacestationssaythistechnologywouldinitiallyrequirealotofmoney,buteventuallyitcouldprovidecontinuous,cleanenergythatwouldbecheaperthanotherfuels.Also,unlikeotherenergysources,solarpowerfromspacewilllastaslongasthesunshines,andwillbeabletoguaranteeeveryoneonEarthalltheenergytheyneed.

Wind

Wind-thefastest-growingalternativeenergysource-isanotherwayofcollectingenergyfromthesun.Windiscausedbythesun'sheatratherthanitslight,andtherefore,unlikesolarpower,itworkswellevenoncloudydays.

AlloverEurope,incentivesdesignedtodecreasethedependenceonoilandcoalhaveledtoasteepincreaseinwind-poweredenergy.Today,Europeleadstheworldinwindpower,producingalmost35,000megawatts1,theequivalentof35largecoal-poweredplants.NorthAmericaremainsadistantsecond,producingjustover7,000megawatts.

Despiteitssuccesses,someopposewind-powerdevelopment,sayingtheturbines2arebothnoisyandugly.JustoutsideEngland'sLakeDistrict,aprotectednationalpark,sevenwindtowersareplanned,eachabout40meters(130feet)tall.Manylocalsareprotesting."Thisisahigh-qualitylandscape,"saysonelocalhomeowner.”Theyshouldn'tbeputtingthosethingsinhere."

Thereareotherchallenges,too.Ifthewinddoesn'tblow,theturbinesarenotabletoproduce

1Amegawattisaunitofpower.

2Aturbineisamachinethatuseswater,steam,orwindtoturnawheeltoproduceelectricity.

adequateenergy.Asaresult,otherpowersourcesareneeded.Incontrast,astrongwindcancreatetoomuchpower.Incaseslikethis,theenergycompanymustselltheextrapoweratamuch-reducedratewhichisnotgoodforbusiness.

What'sneededforbothwindandsolarisawaytostorealargeenergysurplus3.However,mostsystemsarestilldecadesawayfrommakingthisareality.Ontheplusside,bothwindandsolarenablepeopletogeneratetheirownenergywheretheylive:Peoplecanhavetheirownwindmillsorsolarpanels,withbatteriesforcalmdays.

Nuclear

Inthe1970s,nuclearwasseenasthemainenergyalternative.Nuclearpowerproducesvastamountsofelectricitymorecheaplythangasorcoal,withnocarbonemissions.Foranumberofyearsinthe1980sand'90s,however,useofnuclearpowerdeclinedduetoaccidents,concernsaboutnuclearwastestorageanddisposal,andhighconstructioncosts.

Today,timesarechanging.Worldwide,about432plantsnowgenerate13percentoftheplanet'selectricpower,andsomecountrieshaveinvestedheavilyinnuclearenergy.France,forinstance,getsthreequartersofitselectricityfromnuclearpower,thehighestofanycountry.Chinahasstartedtobuildoneortwonewplantsayear,andIndiahasalsobeguntoutilizenuclearenergyonalargescale.However,therearestillconcernsaboutthesafetyofnuclearpower,asseenmostrecentlyattheFukushimanuclearpowerplantinJapan.Thecountryhadtocloseitsnuclearreactorwhentheplantwashitbyatsunamiand,asaconsequence,beganreleasingsubstantialamountsofradioactivematerials.Manystillbelieve,however,thatnuclearpowerisoneofthefuture'sgreenestenergyalternatives.

Intheend,isanyofthesesourcesalonetheanswertoourcurrentenergyproblems?Theshortanswerisno,butusedinsomecombination-alongwithotherpowersources-wemayfindwaystoreduceandeventuallyeliminateourdependenceonfossilfuels.

3Ifyouhaveasurplusofsomething,youhavemoreofitthanyouneed.

ReadingComprehension

MultipleChoice.Choosethebestanswerforeachquestion.

Whatisthisreadingmainlyabout?

possiblereplacementsforfossilfuelsforenergy

thevariouscausesoftheenergycrisistheworldover

thebenefitsofsolarpoweroverotheralternateenergysources

problemscausedbyouroverdependenceonfossilfuels

Inline12,thewordemissionsisclosestinmeaningto

panels b.electricity

c.pollution d.accidents

Whichofthesestatementsaboutsolarenergyisstatedinthetext?

Solariscurrentlythebiggestcontributortotheworld'senergy.

Solarenergyischeaptoproduceduetothelowpriceofsolarpanels.

Solarspacestationscouldbethesolutiontotheenergycrisis.

Solarenergycanhaveaharmfuleffectontheenvironment.

WhatisNOTmentionedasadisadvantageofwindpower?

Strongwindsproducetoomuchpower.

Strongwindscandamagetheturbines.

Theturbinescreatealotofnoise.

Theturbinesareseenasugly.

Whichofthesestatementsistrueaboutnuclearenergyaccordingtothereading?

Itisamoreexpensiveformofenergythancoalorgas.

Itproducesalotofcarbonwaste.

Safetyconcernsma