Review of the Life Cycle Greenhouse Gas Emissions from Different Photovoltaic and Concentrating

18 Pages·2017·1.23 MB·English

energies
Article
Review of the Life Cycle Greenhouse Gas Emissions
from Different Photovoltaic and Concentrating Solar
Power Electricity Generation Systems
RaghavaKommalapati1,2,*,AkhilKadiyala1,Md.TarkikShahriar1,2andZiaulHuque3
1 CenterforEnergy&EnvironmentalSustainability,PrairieViewA&MUniversity,PrairieView,TX77446,
USA;[email protected](A.K.);[email protected](M.T.S.)
2 DepartmentofCivil&EnvironmentalEngineering,PrairieViewA&MUniversity,PrairieView,
TX77446,USA
3 DepartmentofMechanicalEngineering,PrairieViewA&MUniversity,PrairieView,TX77446,USA;
[email protected]
* Correspondence:[email protected];Tel.:[phone]
AcademicEditor:SergioUlgiati
Received:8October2016;Accepted:6March2017;Published:11March2017
Abstract: This paper contains an extensive review of life cycle assessment (LCA) studies on
greenhouse gas emissions (GHG) from different material-based photovoltaic (PV) and working
mechanism-based concentrating solar power (CSP) electricity generation systems. Statistical
evaluation of the life cycle GHG emissions is conducted to assess the role of different PVs and
CSPs in reducing GHG emissions. The widely-used parabolic trough and central receiver CSP
electricitygenerationsystemsemittedapproximately50%moreGHGsthantheparaboloidaldish,
solarchimney,andsolarpondCSPelectricitygenerationsystems. ThecadmiumtelluridePVsand
solarpondCSPscontributedtominimumlifecycleGHGs. Thin-filmPVsarealsosuitableforwider
implementation,duetotheirlowerEnergyPay-BackTime(EPBT)periods,inadditiontolowerGHG
emission,incomparisonwithc-SiPVs.
Keywords: life cycle assessment; greenhouse gas emissions; solar energy; photovoltaics;
concentratingsolarpower;electricitygeneration
1. Introduction
SolarenergymaybedefinedastheenergyharnessedfromthesolarradiationreachingtheEarth’s
surface. Solarenergymaybeharnessedforelectricitygenerationbyusing(a)photovoltaic(PV)and
(b)concentratingsolarpower(CSP)systems.ThePVsystemsworkontheprincipleofdirectconversion
ofsolarradiationintoelectricitywhensunlightcomesincontactwithmaterials(e.g.,semiconductors)
exhibitingthephotoelectriceffect(wherethereisareleaseofelectronsafterabsorptionofphotonsof
light). AcombinationofmultiplePVmodules(acombinationofanumberofsolarcellsconnectedto
eachotherandmountedoveraframe)isgenerallyreferredtoasanarray. ThePVmodulesorarrays
maybeconnectedinseriesorparalleltogenerateelectricity. TheCSPsystemsaccumulatethesun's
energytoareceiverthatservesasaheatsourcetobeused,subsequently,inmovingsteamorwind
turbinestogenerateelectricity. Anintermediatemedium(referredtoastheheattransferfluid)isused
forthetransferofthermalenergytogenerateelectricitywiththecaseofCSPbeinglocatedataplace
differentfromthelocationofthereceiver.
Thetotalelectricitygenerationin2012acrosstheworldwasreportedtobe21.53trillionkWh[1].
Theprojectedworldelectricitygenerationfor2040is39trillionkWh(anincreaseof81%from2012)[2].
Renewableenergysourceshavebeenprojectedtoaccountfor9.6trillionkWh(25%)oftheworld’s
Energies2017,10,350;doi:10.3390/en10030350 www.mdpi.com/journal/energies
Energies2017,10,350 2of18
total electricity generation in 2040. With the continuing depletion of traditional non-renewable
energysources,thenecessityforgeneratingelectricitythroughtheuseofrenewableenergysources
(solar, hydro, wind, biomass, geothermal) increased manifold. Solar energy accounted for only
0.096trillionkWh(0.44%)oftheworld’stotalelectricitygeneratedin2012. Basedonthe2012statistics,
solar energy was the fourth largest renewable energy source for electricity generation after hydro
(3.646trillionkWh),wind(0.52trillionkWh),andbiomass(0.384trillionkWh)[1]. Thesestatistics
indicatethatthereisamplescopetogenerateelectricityonalargescaleusingsolarenergy. Inthe
UnitedStatesofAmerica(USA)alone,solarenergy-basedelectricitygenerationisprojectedtoincrease
from8gigawatts(GW)in2012to48GWin2040. Increasingthecontributionofrenewables,likesolar,
isimperativetolowerglobalGHGemissionsandmeetclimategoals[3].
Undersuchaprojectedincrease, oneneedstoevaluatethesustainabilityofdifferenttypesof
PVsandCSPsbyanalyzinglifecyclegreenhousegas(GHG)emissionsresultingfromtheiradoption.
The life cycle assessment (LCA) approach helps evaluate the net GHG emissions resulting from
the use of solar energy as a fuel. LCA is an analytical method that provides an assessment of the
environmentalimpactsoftheconsideredproductsandtechnologiesfroma‘cradletograve’systems
perspectiveutilizingthedetailedinputandoutputparametersthatoperatewithinthedesignated
systemboundaries.
ManystudiesanalyzedtheLCAofPVs[4–34]andCSPs[35–46]. TheuseofPV/CSPelectricity
generationsystemsaroundtheworldisbeingencouragedinviewoftheadvantagesthatsolarenergyis
afreeandabundantresourcefromwhichelectricitymaybegeneratedwithrelativelylowoperational
and maintenance costs in comparison with other renewable energy sources. The use of PV/CSP
electricitygenerationsystemsisinhibitedbyissuessuchastheintermittencyandtheunpredictability
ofsolarradiationoncloudydays/nightsandtherequirementoflargeareasoflandforutility-scale
CSPinstallation. AmoredetaileddescriptionoftheLCAboundaryconditions,greenhousegas(GHG)
emissions,andsite-specificcharacteristicsassociatedwitheachoftheaforementionedPVandCSP
electricitygenerationsystemstudiesisprovidedintheSections3.1and3.2.
ThemajorityofthePVandCSPLCApublicationstodatehaveemphasizedonthedetermination
ofthelifecycleGHGemissionsfromselectPV/CSPelectricitygenerationsystems. Therewerelimited
studiesthatanalyzedthelifecycleGHGemissionsfromabroaderspectrumofPV[47,48]andCSP[48]
electricitygenerationsystems. NoneoftheearlierstudiesexaminedthelifecycleGHGemissions
andcomparedthemacrossalloffthecurrentlyavailabledistinctPVandCSPelectricitygeneration
system types. This study aims to fill this knowledge gap by performing a comprehensive review
of the literature on all the currently available PV and CSP LCA studies, followed by a statistical
evaluation of the life cycle GHG emissions from the reviewed PV and CSP electricity generation
systemsindividually. TheresultsfromthestatisticalevaluationofthelifecycleGHGemissionswill
assist energy policy-makers and environmental professionals in decision-making and selection of
sustainablesolarsolutionstopowerproduction.
2. Methodology
AreviewoftheliteratureshowedthatthePVandCSPelectricitygenerationsystemsmayfurther
becategorizedonthebasisofmaterialtypeandworkingmechanismgoverningtheaccumulation
of solar energy, respectively. The different categories of PV electricity generation systems [49] are
asfollows:
• Non-organicmaterial-basedPVs:asfollows:
(cid:226) Crystalline-silicon(c-Si): lightisallowedtofilterthroughaseriesoflayerscomprisingofa
protectiveglasscover,atransparentadhesive,andananti-reflectivecoatingmaterialto
reachpositive-andanegative-typesiliconcrystallinematerialsboundtogetherandheld
withpositiveandnegativeelectricalcontacts. Thec-Sicellsarereferredtoasthemono-or
single-crystallinesilicon(sc-Si)cells,whentheyarecutfromasinglehigh-puritycrystal.
Energies2017,10,350 3of18
Ifthec-Sicellsareobtainedintheformofwafersresultingfromtheprocessofcooling
andsolidificationofmoltensiliconcrystalblocks,then,theyaredesignatedaspoly-or
multi-crystallinesilicon(mc-Si)cells.
(cid:226) Thin-films: lightisallowedtofilterthroughaseriesoflayerscomprisingatransparent
coating,ananti-reflectivelayer,positiveandnegativesemi-conductormaterials,acontact
plate and a substrate. Thin films may further be categorized as amorphous-silicon
(a-Si),multi-junctionthin-filmsilicon(µc-Si),cadmiumtelluride(CdTe),copper-indium-
diselenide(CIS),andcopper-indium-gallium-diselenide(CIGS)thinfilmsonthebasisof
thematerialcomponentsused.
• OrganicmaterialbasedPVs:
(cid:226) OrganicPVs(OPV):builtfromthinfilmsoforganicsemiconductorsthatincludepolymers.
(cid:226) Dye-sensitized solar cells (DSSC): consists of a photosensitive dye and is based on a
semiconductorformedbetweenaphoto-sensitizedanodeandanelectrolytethatfacilitates
themovementofelectronstogenerateelectricity
ThedifferentcategoriesofCSPelectricitygenerationsystems[48]areasfollows:
• Parabolictrough: arraysofparabolictroughreflectorsreflectthesunlighttoablackabsorbertube
thatiscooledbyaheat-transferringfluid. Theheat-transferringfluidwhenhot,ispumpedtothe
heatexchangerofasteamRankinecycleforpowergeneration.
• Centralreceiver: solarradiationisreflectedontoacentrallyplacedreceivermountedoverthetop
ofatowerbyacollectorthatcomprisesoftwolargeheliostats.
• Paraboloidaldish:aparaboloidaldishreflectorisusedasasolarcollectorandtheheattoelectricity
conversionisachievedbyusingaStirlingengine.
• Solarchimney:aflatareaiscoveredbyaglasscover(withsoilandairunderneath)thatisinclined
towardthemiddle,whereachimneyislocatedatthecenterandisexposedtothesun. Thehotair
risingupthroughthechimneygenerateselectricitybyusingawindturbine.
• Solarpond: alargereservoirofwaterwithablackbottomabsorbssolarradiationandtransforms
itintoheatintheformofhotwater.
ThisstudyadoptedthesameclassificationofPVs(sc-Si,mc-Si,a-Si,µc-Si,CdTe,CIS,CIGS,OPV,
DSSC)andCSPs(parabolictrough,centralreceiver,paraboloidaldish,solarchimney,solarpond)on
thebasisoftheclassificationsproposedbytheIPCCReport[49]andAmponsahetal.[48],respectively,
to evaluate the life cycle GHG emissions from using different PV and CSP electricity generation
systems. EachofthereviewedPVandCSPLCAstudywasfirstassignedadistinctcategory. Next,
thelifecycleGHGemissionsfrommaterial-basedPVandworkingmechanism-basedCSPelectricity
generationsystemswereevaluatedusingstatisticalmetrics(samplesize,mean,standarddeviation,
minimum,maximum,standarderrorofthemean,quartile1,quartile2ormedian,quartile3)and
graphicalrepresentations(errorbarsrepresentingthemeanwith95%confidenceintervals,boxplots
representingthequartileswithoutliers). Whiletheerrorbarsdemonstratethedegreeofconfidencein
themeanGHGemissions,theboxplotsprovideinformationonthedegreeofvariationamongthe
LCAstudiescharacterizedbydifferentPVandCSPcategories.
3. ResultsandDiscussion
3.1. ReviewofPVLCAStudies
Therearenumerousstudies[4–34]thatevaluatedthelifecycleenvironmentalimpactsofusing
PVsforelectricitygeneration. Oneneedstodefinethesystemboundaryconditions(thatincludes
detailsontheactivitiesorprocessestobeconsideredintheanalysis)andafunctionalunitofmeasure
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(thatenablesquantificationofthenetenvironmentalimpactsfromcarryingoutanactivityoraprocess
asdefinedwithintheLCAsystemboundaryconditions)whenperformingaLCA.
The majority of the aforementioned studies [6,8,13,17–19,22,23,28,30–32,34] that performed
the LCA of PV electricity generation systems defined the system boundary conditions to include
activitiessuchasrawmaterialextraction,manufacturingprocesses,transport,installation,operation,
maintenance, and end-of-life processes (dismantling, recycling, and final disposal). Some
studies[11,16,29]excludedtheconsiderationofend-of-lifeprocessestodefinetheirsystemboundaries
tobelimitedtorawmaterialextraction,manufacturingprocesses,transport,installation,operation,
and maintenance. The remaining studies [4,5,7,9,10,12,14,15,18,20,21,24–27,33] limited the system
boundariestoPVmoduleproduction.
ThecommonfunctionalunitofmeasureadoptedbythemajorityofthePVLCAstudiesisgrams
ofcarbondioxideequivalentperkilowatthour(gCO e/kWh)ofelectricityproduced. Accordingly,
2
this study also adopts the functional unit of measure for GHG emissions to be gCO e/kWh of
2
electricityproduced.
Table 1 provides a summary of the PV module categorization (based on the type of material)
along with the corresponding GHG emissions (in gCO e/kWh) and energy payback time (EPBT,
2
expressedinyears)periodsforeachofthereviewedPVLCAstudy. Table1alsoprovidesadditional
site-specific details that included module efficiency (η , expressed in %), performance ratio (η ,
1 2
expressed in %), power rating (PR, expressed in kW), available solar radiation at the location (SR,
expressedinkWh/m2/yr),thetypeofinstallation(TI:roof-top/ground-mount/building-integrated
with the angle of tilt), and the geographical location (GL) for the installed PV systems. The EPBT
maybedefinedasthetimeperiodforwhichaPVsystemshouldoperatetorecoveranequivalent
amountofenergyspentintheproductionoftheinstalledPVsystem. η providesameasureofthe
1
performanceofthePVmoduleingeneratingenergyfromsunlightandisdefinedastheratioofenergy
outputfromthePVmoduletotheinputenergyfromthesun. η isdefinedastheratiooftheactual
2
andtheoreticallypossibleenergyoutputsandmaybeusedincomparingthePVsystemsatdifferent
locationsacrosstheworld(consideringthatη isindependentoftheorientationandtheamountof
2
incidentsolarradiation). Basedonthereviewof31PVelectricitygenerationLCAstudies(referto
Table1),onemaynotethatmc-Si(N =35)PVelectricitygenerationsystemsweremoreinnumber
comparedtosc-Si(N=24),CdTe(N=21),a-Si(N=16),CIS(N=3),DSSC(N=2),µc-Si(N=1),and
CIGS(N =1)PVelectricitygenerationsystems. TherewerenoLCAstudiesontheuseofOPVsin
electricitygeneration.
Table1.GreenhouseGas(GHG)emissionsandEnergyPay-BackTime(EPBT)periodsforphotovoltaic
(PV)electricitygenerationsystems.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
sc-Si(annualcellproductionof
2.5MWperyear;annualload 130 3.7 η1=14;PR=300;
GL=Germany
durationtimeof2000hperyear)
sc-Si(annualcellproductionof
2.5MWperyear;annualload 250 7.3 η1=14;PR=300;
GL=Germany
Schaeferand durationtimeof1000hperyear)
Hagedorn[4]
sc-Si(annualcellproductionof
25MWperyear;annualload 70 3.7 η1=15.5;PR=1500;
GL=Germany
durationtimeof2000hperyear)
sc-Si(annualcellproductionof
25MWperyear;annualload 150 7.3 η1=15.5;PR=1500;
GL=Germany
durationtimeof1000hperyear)
Energies2017,10,350 5of18
Table1.Cont.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
mc-Si(annualcellproductionof
2.5MWperyear;annualload 120 3.6 η1=12;PR=300;
GL=Germany
durationtimeof2000hperyear)
mc-Si(annualcellproductionof
2.5MWperyear;annualload 250 7.1 η1=12;PR=300;
GL=Germany
durationtimeof1000hperyear)
mc-Si(annualcellproductionof
25MWperyear;annualload 50 3.6 η1=13.5;PR=1500;
GL=Germany
durationtimeof2000hperyear)
mc-Si(annualcellproductionof
Schaeferand 25MWperyear;annualload 110 7.1 η1=13.5;PR=1500;
GL=Germany
Hagedorn[4] durationtimeof1000hperyear)
a-Si(annualcellproductionof
2.5MWperyear;annualload 90 2.9 η1=6;PR=300;
GL=Germany
durationtimeof2000hperyear)
a-Si(annualcellproductionof
2.5MWperyear;annualload 170 5.8 η1=6;PR=300;
GL=Germany
durationtimeof1000hperyear)
a-Si(annualcellproductionof
25MWperyear;annualload 50 2.9 η1=8;PR=1500;
GL=Germany
durationtimeof2000hperyear)
a-Si(annualcellproductionof
25MWperyear;annualload 100 5.8 η1=8;PR=1500;
GL=Germany
durationtimeof1000hperyear)
mc-Si(worstcase) 167 3.8 η1=13;η2=75;SR=1000;
Netherlands GL=Netherlands
AgencyforEnergy
andthe mc-Si(basecase) 31 1.3 η1=16;η2=80;SR=1000;
GL=Netherlands
Environment
Report[5] mc-Si(bestcase) 9.8 0.5 η1=18;η2=85;SR=1000;
GL=Netherlands
Nieuwlaaretal.[6] a-Si 47 4 η1=10;TI=roof-top;
GL=Netherlands
sc-Si(worstcase) 91 15.5 η2=81;PR=3;SR=1427;
TI=roof-top;GL=Japan
sc-Si(basecase) 65 11 η2=81;PR=3;SR=1427;
TI=roof-top;GL=Japan
Katoetal.[7] sc-Si(optimisticcase) 21 4 η2=81;PR=3;SR=1427;
TI=roof-top;GL=Japan
mc-Si 18 2.5 η2=81;PR=3;SR=1427;
TI=roof-top;GL=Japan
a-Si 15 1.5 η2=81;PR=3;SR=1427;
TI=roof-top;GL=Japan
mc-Si 189 NA η1=14;PR=3;
Donesand TI=roof-top;GL=Switzerland
Frischknecht[8]
sc-Si 114 NA η1=16.5;PR=3;
TI=roof-top;GL=Switzerland
η1=11.2;PR=20;
Frankletal.[9] sc-Si 200 9 SR=1700;TI=roof-top,30◦tilt;
GL=Italy
Energies2017,10,350 6of18
Table1.Cont.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
η1=12.2;η2=81;PR=3;
sc-Si(worstcase) 83 11.8 SR=1427;TI=roof-top;
GL=Japan
η1=12.2;η2=81;PR=3;
sc-Si(basecase) 61 8.9 SR=1427;TI=roof-top;
GL=Japan
η1=12.2;η2=81;PR=3;
sc-Si(bestcase) 25 3.3 SR=1427;TI=roof-top;
GL=Japan
mc-Si(annualcellproductionof η1=11.6;η2=81;PR=3;
20 2.4 SR=1427;TI=roof-top;
10MWperyear)
GL=Japan
Katoetal.[10]
mc-Si(annualcellproductionof η1=11.7;η2=81;PR=3;
18 2.2 SR=1427;TI=roof-top;
30MWperyear)
GL=Japan
mc-Si(annualcellproductionof η1=15.7;η2=81;PR=3;
13 1.5 SR=1427;TI=roof-top;
100MWperyear)
GL=Japan
a-Si(annualcellproductionof η1=8;η2=81;PR=3;
17 2.1 SR=1427;TI=roof-top;
10MWperyear)
GL=Japan
a-Si(annualcellproductionof η1=10;η2=81;PR=3;
13 1.7 SR=1427;TI=roof-top;
30MWperyear)
GL=Japan
a-Si(annualcellproductionof η1=12;η2=81;PR=3;
9 1.1 SR=1427;TI=roof-top;
100MWperyear)
GL=Japan
η1=3.89;
Lewisetal.[11] a-Si 187.8 5.14 TI=building-integrated;
GL=USA
sc-Si 60 3.2 η1=14;SR=1700;TI=roof-top;
GL=Netherlands
Alsema[12] mc-Si 50 3.2 η1=13;SR=1700;TI=roof-top;
GL=Netherlands
a-Si 50 2.7 η1=7;SR=1700;TI=roof-top;
GL=Netherlands
η1=14;η2=55;
mc-Si 120 NA TI=building-integrated;
GL=SwissJuraAlps,Europe
OliverandJackson
[13] η1=14;η2=85;
mc-Si 170 NA TI=building-integrated;
GL=SwissJuraAlps,Europe
DSSC 19 NA η1=7;η2=53;SR=2190;
GL=SaharaDesert,Africa
Greijeretal.[14]
DSSC 47 NA η1=12;η2=53;SR=2190;
GL=SaharaDesert,Africa
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Table1.Cont.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
CdTe(annualcellproductionof η1=10.3;η2=81;PR=3;
14 1.7 SR=1427;TI=roof-top;
10MWperyear)
GL=Japan
Katoetal.[15] CdTe(annualcellproductionof η1=11.2;η2=81;PR=3;
11.5 1.4 SR=1427;TI=roof-top;
30MWperyear)
GL=Japan
CdTe(annualcellproductionof η1=12.4;η2=81;PR=3;
8.9 1.1 SR=1427;TI=roof-top;
100MWperyear)
GL=Japan
mc-Si 104 NA GL=Japan
Nomuraetal.[16]
mc-Si 133 NA GL=Japan
η1=5.7;
Meier[17] a-Si 39 4.9 TI=building-integrated;
GL=USA
η1=12.8;η2=78;PR=1,000,000;
SR=1854(10◦tilt)-2037
Itoetal.[18] mc-Si 12 1.7 (40◦tilt);TI=ground-mount;
GL=GobiDesert,China
FthenakisandKim η1=9;η2=80;PR=25,000;
CdTe 23.6 1.2 SR=1800;TI=ground-mount;
[19]
GL=USA
sc-Si 35 2.6 η1=14;η2=75;SR=1700;
TI=roof-top;GL=Europe
Alsemaetal.[20] mc-Si 32 1.9 η1=13.2;η2=75;SR=1700;
TI=roof-top;GL=Europe
η1=9;η2=75;SR=1700;
CdTe 25 1.1 TI=ground-mount;
GL=Europe
mc-Si 37 2.2 η1=13.2;η2=75;SR=1700;
TI=roof-top;GL=Europe
Fthenakisand CdTe 21 1 η1=8;η2=75;SR=1700;
Alsema[21] TI=roof-top;GL=Europe
CdTe 25 1.1 η1=9;η2=75;SR=1700;
TI=roof-top;GL=US
Kannanetal.[22] sc-Si 165 4.47 η1=11.86;PR=2.7;SR=1635;
TI=roof-top;GL=Singapore
mc-Si 37 NA η1=13.2;η2=80;SR=1700;
TI=roof-top;GL=Europe
FthenakisandKim sc-Si 45 NA η1=14;η2=80;SR=1700;
[23] TI=roof-top;GL=Europe
CdTe 16 NA η1=9;η2=80;SR=1700;
TI=roof-top;GL=Europe
a-Si 34.3 3.2 η112=◦6t.i3l;t;SGRL==13M59ic;hTiIg=anr,oUofS-tAop,
Paccaetal.[24] η1=12.92;SR=1359;
mc-Si 72.4 7.4 TI=roof-top,12◦tilt;
GL=Michigan,USA
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Table1.Cont.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
mc-Si(worstcase) 167 5.5 η1=14;η2=75;SR=1700;
TI=roof-top;GL=Europe
mc-Si(basecase) 72 2.4 η1=14;η2=75;SR=1700;
TI=roof-top;GL=Europe
Raugeietal.[25] mc-Si(bestcase) 57 2.5 η1=14;η2=75;SR=1700;
TI=roof-top;GL=Europe
CIS 95 2.8 η1=11;η2=75;SR=1700;
TI=roof-top;GL=Europe
CdTe 48 1.5 η1=9;η2=75;SR=1700;
TI=roof-top;GL=Europe
sc-Si(CrystalClearprojectwith η1=14;η2=80;SR=1700;
32 NA TI=ground-mount;
Ecoinventdatabase)
GL=Europe
sc-Si(UCTEgridmixturewith η1=14;η2=80;SR=1700;
42 NA TI=ground-mount;
Ecoinventdatabase)
GL=Europe
sc-Si(USgridmixturewith η1=14;η2=80;SR=1700;
52 NA TI=ground-mount;
Franklindatabase)
GL=USA
mc-Si(CrystalClearprojectwith η1=13.2;η2=80;SR=1700;
Fthenakisetal.[26] Ecoinventdatabase) 31 NA TI=ground-mount;
GL=Europe
mc-Si(UCTEgridmixturewith η1=13.2;η2=80;SR=1700;
41 NA TI=ground-mount;
Ecoinventdatabase)
GL=Europe
mc-Si(USgridmixturewith η1=13.2;η2=80;SR=1700;
51 NA TI=ground-mount;
Franklindatabase)
GL=USA
CdTe(UCTEgridmixturewith 20 NA η1=9;η2=80;SR=1700;
Ecoinventdatabase) TI=roof-top;GL=Europe
CdTe(USgridmixturewith 26 NA η1=9;η2=80;SR=1700;
Franklindatabase) TI=roof-top;GL=USA
η1=12.8;η2=78;PR=100,000;
SR=1702(horizontal)-2017
mc-Si 12.1 1.9 (30◦tilt);TI=ground-mount;
GL=GobiDesert,China
η1=15.8;η2=78;PR=100,000;
SR=1702(horizontal)-2017
mc-Si 9.4 1.5 (30◦tilt);TI=ground-mount;
GL=GobiDesert,China
Itoetal.[27]
η1=6.9;η2=77.1;PR=100,000;
SR=1702(horizontal)-2017
a-Si 15.6 2.5 (30◦tilt);TI=ground-mount;
GL=GobiDesert,China
η1=9;η2=77.2;PR=100,000;
SR=1702(horizontal)-2017
CdTe 12.8 1.9 (30◦tilt);TI=ground-mount;
GL=GobiDesert,China
Energies2017,10,350 9of18
Table1.Cont.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
η1=11;η2=77.6;PR=100,000;
SR=1702(horizontal)-2017
Itoetal.[27] CIS 10.5 1.6 (30◦tilt);TI=ground-mount;
GL=GobiDesert,China
García-Valverde sc-Si 131 9.08 η2=T6I2=;ProRo=f-t4o.2p4,;3S0R◦t=ilt1;932;
etal.[28]
GL=Murcia,Spain
η2=78;SR=1702;
sc-Si 51 2.5 TI=ground-mount;
GL=GobiDesert,China
η2=78;SR=1702;
mc-Si 42 2 TI=ground-mount;
GL=GobiDesert,China
Itoetal.[29] η2=78;SR=1702;
a-Si 43 2.1 TI=ground-mount;
GL=GobiDesert,China
η2=78;SR=1702;
CIS 46 1.8 TI=ground-mount;
GL=GobiDesert,China
η2=78;SR=1702;
CdTe 51 2.1 TI=ground-mount;
GL=GobiDesert,China
sc-Si 98.9 3.8 η22=2◦75ti;ltS;RG=L1=7G00r;oTssIe=tor,oIotfa-ltyop,
Bravietal.[30] mc-Si 180.3 3.5 η22=2◦75ti;ltS;RG=L1=7G00r;oTssIe=tor,oIotfa-ltyop,
a-Si,CIGS,CdTe,µc-Si 39.2 2.5 η22=2◦75ti;ltS;RG=L1=7G00r;oTssIe=tor,oIotfa-ltyop,
η1=14;η2=80;PR=24;
sc-Si 38 2.4 SR=1700-2280;TI=roof-top;
GL=Europe
FthenakisandKim η1=13.2;η2=80;PR=24;
mc-Si 30 1.9 SR=1700-2280;TI=roof-top;
[31]
GL=Europe,USA
η1=9;η2=80;PR=24;
CdTe 19 0.7 SR=1700-2280;TI=roof-top;
GL=Europe,USA
η1=10.9;η2=80;PR=200,000;
CdTe 29.5 1.1 SR=1200;TI=ground-mount;
GL=CentralEurope(Germany)
η1=10.9;η2=80;PR=200,000;
SR=1700;TI=ground-mount;
HeldandIig[32] CdTe 20.9 0.76
GL=Mediterraneanregion,
Europe(Italy)
η1=10.9;η2=80;PR=200,000;
SR=1700;TI=ground-mount;
CdTe 20.9 0.9
GL=Mediterraneanregion,
Europe(EU-25)
Energies2017,10,350 10of18
Table1.Cont.
PVCategory GHG AdditionalFeatures
EPBT
Source (SupplementaryCase Emissions (Years) η1(%),η2(%),PR(kW),
Description) (gCO2e/kWh) SR(kWh/m2/yr),TI,GL
η1=10.9;η2=80;PR=200,000;
CdTe 18.7 0.7 SR=1900;TI=ground-mount;
GL=Spain
HeldandIig[32]
η1=10.9;η2=80;PR=200,000;
CdTe 18.7 0.9 SR=1900;TI=ground-mount;
GL=Portugal
η1=14;η2=75;SR=1700;
sc-Si 38 1.7 TI=roof-top;
GL=SouthernEurope
International η1=13.2;η2=75;SR=1700;
EnergyAgency mc-Si 34 1.7 TI=roof-top;
Report[33] GL=SouthernEurope
η1=10.9;η2=75;SR=1700;
CdTe 18 0.8 TI=roof-top;
GL=SouthernEurope
η1=14.4;η2=80;PR=1778;
Desiderietal.[34] mc-Si 88.74 4.17 TI=ground-mount,25◦tilt;
GL=Perugia,Italy
Tiltofsolarpanels:dueSouthunlessspecified.NA:notavailable.PR:powerrating.SR:solarradiation.TI:typeof
installation.GL:geographicallocation.
3.2. ReviewofCSPLCAStudies
Many studies [35–46] evaluated the life cycle environmental impacts of using CSP electricity
generationsystems. ThemajorityoftheCSPstudies[35,37,39–42,44–46]definedtheLCAboundary
conditionstoincludeactivities,suchasmanufacturing(extractionofrawmaterials,transportationto
themanufacturingfacility,componentmanufacturingprocesses,transportationofthefinalproductto
regionalstorage),construction(activitiesassociatedwithsiteimprovements,transportingcomponents
tothesite,plantassembly),operation,andmaintenance(manufactureofreplacementcomponents
andtheirtransportationtothesite,waterconsumptioninthepowerblockandformirrorcleaning,
fuel consumption in cleaning/maintenance vehicles, on-site natural gas combustion, electricity
consumptionfromtheregionalpowergrid),dismantling(energyrequiredtodisassemblethemajorCSP
plantsystems),anddisposal(energyrequiredtotransportdemolitionwastetothelandfill,incinerator,
recyclingplant,orre-manufacturerandtheenergyrequiredforfinaldisposal). Onestudy[38]limited
thelifecycleboundaryconditionstoincludeonlymaterialproduction.
Table 2 provides a summary of the CSP electricity generation systems (based on the type of
working mechanism) along with the corresponding GHG emissions (in gCO e/kWh) and EPBT
2
periods(inyears)foreachofthereviewedCSPelectricitygenerationLCAstudy. Table2alsopresents
additional site-specific features that included power rating (PR, expressed in kW), available solar
radiationatthelocation(SR,expressedinkWh/m2/yr),andthegeographicallocation(GL)forthe
installed CSP systems. Based on the review of 12 CSP electricity generation LCA studies (refer to
Table2),onemaynotethatparabolictrough(N=10)CSPelectricitygenerationsystemsweregreater
innumbercomparedtocentralreceiver(N=9),solarchimney(N=3),paraboloidaldish(N=2),and
solarpond(N=2)CSPelectricitygenerationsystems.