能源有效性与可再生能源.ppt

,,Chapter8,EnergyEfficiencyandRenewableEnergy能源有效性与可再生能源,,,,KeyConcepts,EnergyuatingenergyresourcesImprovingenergyefficiency,,Typesandusesofsolarenergy,Typesandusesofflowingwater,Usesofwindenergy,Typesandusesofbiomass,Useofhydrogenasafuel,Useofgeothermalenergy,Decentralizedpowersystems,,,Glossary,energyefficiencyPercentageofthetotalenergythatdoesusefulworkandisnotconvertedintolow-quality,usuallyuselessheatinanenergyconversionsystemorprocess.Seeenergyquality,netenergy.Comparematerialefficiency.geothermalenergyHeattransferredfromtheearthsundergroundconcentrationsof1drysteamsteamwithnowaterdroplets,2wetsteamamixtureofsteamandwaterdroplets,or3hotwatertrappedinfracturedorporousrock.,,,Energys,,Kineticenergy,Potentialenergy,Heat,,,Glossary,kineticenergyEnergythatmatterhasbecauseofitsmassandspeedorvelocity.Comparepotentialenergy.potentialenergyEnergystoredinanobjectbecauseofitspositionorthepositionofitsparts.Comparekineticenergy,,,TransferofHeatEnergy,,,,,EnergyQuality,High-qualityenergy,Low-qualityenergy,,,,uatingEnergyResources,,Renewableenergy,Non-renewableenergy,Futureavailability,Netenergyyield,Cost,Environmentaleffects,,,Glossary,nonrenewableresourceResourcethatexistsinafixedamountstockinvariousplacesintheearthscrustandhasthepotentialforrenewalbygeological,physical,andchemicalprocessestakingplaceoverhundredsofmillionstobillionsofyears.Examplesarecopper,aluminum,coal,andoil.Weclassifytheseresourcesasexhaustiblebecauseweareextractingandusingthematamuchfasterratethantheywereed.CenergyTotalamountofusefulenergyavailablefromanenergyresourceorenergysystemoveritslifetime,minustheamountofenergy1usedthefirstlawofthermodynamics,2automaticallywastedthesecondlawofthermodynamics,and3unnecessarilywastedinfinding,processing,concentrating,andtransportingittousers.,,,ImportantNonrenewableEnergySources,,,,NuclearEnergy,Fissionreactors,,Uranium-235,Potentiallydangerous,Radioactivewastes,,,Glossary,nuclearenergyEnergyreleasedwhenatomicnucleiundergoanuclearreactionsuchasthespontaneousemissionofradioactivity,nuclearfission,ornuclearfusion.,,,TheImportanceofImprovingEnergyEfficiency,,Netusefulenergy净有用能源,Lifecyclecost,LeastEfficient,Incandescentlights,Internalcombustionengine,Nuclearpowerplants,,,Efficiencies,,,,WaystoImproveEnergyEfficiency,,Insulation,Eliminationofairleaks,Airtoairheatexchangers,Cogeneration,Efficientelectricmotors,High-efficiencylighting,Increasingfueleconomy,,,Glossary,cogenerationProductionoftwousefulsofenergy,suchashightemperatureheatorsteamandelectricity,fromthesamefuelsource.,,,ElectricandHybridCars,,Rechargeablebatterysystems,Hybridelectric-internalcombustionengine,Fuelcells,,,,UsingSolarEnergytoProvideHeatandElectricity,,Passivesolarheating,Activesolarheating,,,Glossary,activesolarheatingsystemSystemthatusessolarcollectorstocaptureenergyfromthesunandstoreitasheatforspaceheatingandwaterheating.Liquidorairpumpedthroughthecollectorstransfersthecapturedheattoastoragesystemsuchasaninsulatedwatertankorrockbed.Pumpsorfansthendistributethestoredheatorhotwaterthroughoutadwellingasneeded.Comparepassivesolarheatingsystem.passivesolarheatingsystemSystemthatcapturessunlightdirectlywithinastructureandconvertsitintolow-temperatureheatforspaceheatingorforheatingwaterfordomesticusewithouttheuseofmechanicaldevices.Compareactivesolarheatingsystem.,,,UsingSolarEnergytoProvideHigh-TemperatureHeatandElectricity,,Solarthermalsystems,PhotovoltaicPVcells,,,,Glossary,solarcellSeephotovoltaiccell.photovoltaiccellsolarcellDevicewhichconvertsradiantsolarenergydirectlyintoelectricalenergy.solarcollectorDeviceforcollectingradiantenergyfromthesunandconvertingitintoheat.Seeactivesolarheatingsystem,passivesolarheatingsystem.,,,ProducingElectricityfromMovingWater,,Large-scalehydropower,Small-scalehydropower,Pumped-storagehydropower,Tidalpowerplant,Wavepowerplant,,,ProducingElectricityfromHeatStoredinWater,,OceanthermalenergyconversionOTEC,Salinesolarponds,Freshwatersolarponds,,,ProducingElectricityfromWind,,,,ProducingEnergyfromBiomass,,Biofuels,Biomassplantations,Cropresidues,Animalmanure,Biogas,Ethanol,Methanol,,,,Glossary,biofuelGasorliquidfuelsuchasethylalcoholmadefromplantmaterialbiomass.,,,TheSolar-HydrogenRevolution,,Extractinghydrogenefficiently,Storinghydrogen,Fuelcells,,,,GeothermalEnergy,Geothermalreservoirs,,Drysteam,Wetsteam,Hotwater,Moltenrock,Hotdry-rockzones,,,,EnteringtheAgeofDecentralizedMicropower,Centralizedpowersystems,,Decentralizedpowersystems,Micropowersystems,,,,,Glossary,micropowersystemsSystemsofsmall-scaledecentralizedunitsthatgenerate1-10,000kilowattsofelectricity.Examplesinclude1microturbines,2fuelcells,and3householdsolarpanelsandsolarroofs.,,,SolutionsASustainableEnergyStrategy,,,