clear sky and all-weather global and beam irradiance models: long term validation

6th Performance Modeling Workshop 2016Pierre Ineichen, Université de Genève

Clear sky and all-weather global and beam irradiance models: long term validation

Dr Pierre Ineichen

University of Geneva – Institute of Environmental Sciences


Solarresource:fromgroundtobankabledata

Statement#1ï itisillusorytodevelopandtovalidatesolarresource

modelswithouthighqualitygroundmeasurements

Statement#2ï highqualitybankabledatagothroughastringent

processofacquisitionandqualitycontrolofthedata

Statement#3ï highqualitymodeleddataarebasedonthe

knowledgeofpreciseinputparameterswithadaptedspaceandtimegranularity,mainlyatmosphericaerosolcontentandwatervaporcolumn


Solarresourceassessment

Groundmeasurementsï situationandsitecharacterizationï typeofsensors,calibrationandcharacterization

Dataarchivingï measurementscontinuity,gapfillingï dataqualitycontrol(onlineandlongterm)ï format,Metadata,dissemination

Modelingï satellitedata(Meteosat,Goes,etc.images)ï inputparameters(turbidity,watervapor,etc.)ï granularity(terrainaggregation,aod,w)ï components(clearsky,beam,tilted,etc.)

Modelvalidationï grounddata(climate,latitude,altitude,etc)ï qualitycontrol(ground&model)ï comparisonstatistics(first&secondorder)ï resultspresentation


Validationbackground

ð 22groundsites,inEuropeandMediterraneanregion,ð latitude:20° ->60°,altitude:0m->1600mð validationoverupto8years,global,diffuseandnormalbeamcomponents(when

onlyglobalcomponent,beamfromDirIndex)ð hourly,dailyandmonthly valuescomparisonð aod inputdata:MACCproject,aeronet andMolineaux-Ineichen(bmpi retrofit model)ð clearskymodels:CAMSMcClear,Solis,REST2,CPCR2,Bird,ESRAandKastenð all-weathermodels:14global,9beamirradiance,average(8)andrealtime(6)ð Interannualvariability

Modelvalidation

1993

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2010

2011

2012

2013

Almeria(Spain)Bratislava(Slovakia)Cabauw(theNetherlands)Carpentras(France)Davos(Switzerland)Geneva(Switzerland)Kassel(Germany)MtKenya(Kenya)Kishinev(Moldavia)Lerwick(GreatBritain)Lindenberg(Germany)Madrid(Spain)Nantes(France)Payerne(Switzerland)SedeBoqer(Israel)Skukuza(SouthAfrica)Tamanrasset(Algeria)Toravere(Estonia)Valentia(Ireland)Vaulx-en-Velin(France)Wien(Austria)Zilani(Letonia)


Dataqualitycontrol

Timestampvalidation(acquisitiontime)ï solartimesymmetry(irradianceorclearnessindexKt)

Dataabsolutecalibrationï comparisonwithancillarydata(aeronet,nearbysite,etc.)ï yeartoyearcomparison(stability)

Componentscoherenceï 3components:«closureequation»:global=direct+diffuseï 2components:coherencewithSolisclearskymodel


Validationstatistics

ð meanbiasdifference(mbd)ð meanabsolutebiasdifference(mabd)ð rootmeansquaredifference(rmsd)ð standarddeviation(sd)ð correlationcoefficient(RorR2)ð Kolmogorov-Smirnovintegral(KSI)ð standarddeviationofthebiases

Includingthedispersioninducedby:

ð groundmeasurementsuncertaintyð comparisonperiodlengthð algorithmsprecisionð qualityoftheinputdata(aod,w,etc.)ð comparisonofdatawithdifferenttime/space

granularities

Validationstatistics

𝑚𝑏𝑑 = ∑(𝐺𝑠𝑎𝑡 − 𝐺𝑚𝑒𝑠 )

𝑁

𝑟𝑚𝑠𝑑 = '∑(𝐺𝑠𝑎𝑡 − 𝐺𝑚𝑒𝑠 )2

𝑁

𝑠𝑑 = %∑(𝐺𝑠𝑎𝑡 − 𝐺𝑚𝑒𝑠 )2

𝑁

𝑅 =∑%𝐺𝑠𝑎𝑡 −𝐺𝑠𝑎𝑡 +%𝐺𝑚𝑒𝑠 −𝐺𝑚𝑒𝑠 +

.(∑(𝐺𝑠𝑎𝑡 −𝐺𝑠𝑎𝑡 )2)(∑(𝐺𝑚𝑒𝑠 −𝐺𝑚𝑒𝑠)2)

𝐾𝑆𝐼 = & |𝐹𝑐(𝐺𝑠𝑎𝑡 ) −𝐹𝑐(𝐺𝑚𝑒𝑠 )| ∙ 𝑑𝐺𝑚𝑒𝑠𝐺𝑚𝑎𝑥

𝐺𝑚𝑖𝑛


Resultspresentation

ð scatterplots(Gh,Dh,Bn)

ð biasdependence(skytype,aod)

ð clearnessindexversussolarelevation

ð frequencydistribution

ï irradiance,Kt,cumulated

ï biasaroundthe1:1axis

ð Comparisonof monthlyvalues:seasonaldependence

ð tables,histograms,etc.

Resultspresentation


FromMACCprojectð retrievedbyMinesParisTech,

Fromgroundmeasurements:Molineaux-Ineichenbmpimodelð IntegratedModtran &smarts2RTMcalculationð Dcda =-0.101+0.235amR

-0.16 Dw =0.112amR-0.55 w0.34

ð aod retro-calculatedfromDNI&GHIwithSolis

FromAeronet network(groundmeasurements)ð level2.0(ifnotavailable,level1.5)indailyvalues

Comparisonð Solisretrofit/aeronet aod (dailyvalues):5%bias,good

correlation(bothissuedfromgroundmeasurements)ð Macc/aeronet(dailyvalues):highdispersionandbiasð w(Ta,HR)/aeronet:nobias,highdispersion,lowimpacton

themodelsresults

Inputdata


Overallresultsð negligiblebiasð GHI:sd =2.5%- 3%ð DNI:sd = 3%- 10%

Standarddeviationofthebiasð GHI:∼ 20W/m2 3.5%ð DNI:∼ 25- 39W/m2 3%- 5%ð DIF:∼ 25W/m2 25%

Clearskymodelvalidation


Biasdependence

ð with theaerosolopticaldepthð slightdependencewithMACCaerosol

asinputð nospecificpatternwithbmpi aod as

input

ð nospecificseasonaldependence

ð thedistributionofthebiasaroundthe1:1axisisnearofnormal(exceptforDavosandMtKenya)->firstorderstatisticreliable

ð thehighestbeammeasurementsareneverreachedbythemodelledvalueswhateverthemodelis

Clearskymodelvalidation


Representationsð DiffusefractionDHI/GHI,Kt andKb

versussolarelevationangleandKt

Clearskymodels’behavior


Overallvalidationresults:

ð performanceoverallthedata(110site-year,475’000hourlyvalues,43’000dailyvalues,1’700monthlyvalues)

í hourly: nobias,sd(Gh)=17-20%, bias2%,sd(Bn)=34-50%

í daily: nobias, sd(Gh)=8-12%, bias2%, sd(Bn)=20-32%

í monthly: nobias, sd(Gh)= 3-6%, bias2%, sd(Bn)=9-17%

mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd

0 57 -6 119 7 47 5 70 21 166 -13 60 6 80 -40 170 33 800% 17% -2% 34% 5% 35% 1% 20% 6% 47% -10% 45% 2% 23% -11% 49% 25% 60%

0.00 0.29 -0.05 0.75 0.07 0.32 0.05 0.44 0.22 1.25 -0.14 0.46 0.07 0.49 -0.39 1.23 0.33 0.620% 8% -1% 20% 5% 22% 1% 12% 6% 32% -9% 31% 2% 13% -10% 32% 23% 42%

-0.1 3.6 -1.7 10.4 2.3 4.5 1.5 7.5 6.6 18.6 -4.1 6.1 2.0 6.2 -12.6 16.6 10.5 9.60% 3% -2% 9% 5% 11% 1% 7% 6% 17% -10% 14% 2% 6% -11% 15% 25% 23%

bias sd

mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd mbd sd

4 66 0 140 5 55 0 75 7 165 2 55 2 81 -1 174 5 621% 19% 0% 39% 4% 41% 0% 22% 2% 47% 2% 42% 1% 24% 0% 49% 4% 46%

0.04 0.33 0.02 0.90 0.05 0.39 0.00 0.43 0.07 1.10 0.03 0.39 0.02 0.44 0.00 1.17 0.04 0.411% 9% 0% 23% 3% 27% 0% 12% 2% 30% 2% 28% 0% 12% 0% 31% 3% 30%

1.1 4.2 0.3 12.1 1.6 5.2 0.1 5.0 2.0 11.7 0.8 4.8 0.6 6.4 -0.3 15.8 1.6 5.31% 4% 0% 11% 4% 12% 0% 5% 2% 11% 2% 12% 1% 6% 0% 15% 4% 13%

bias sd

SolarGis Helioclim 3 Solemi

Heliomont

Gh Bn Dh Gh Bn Dh Gh Bn Dh

131 340

Dh Gh Bn Dh

134

1.46

hourly [Wh/m2h]

341 351 134 345 354 134 342 350

346 354

CM-SAF IrSOLaVGh Bn Dh Gh

3.73 1.38 3.60 3.73 1.41

353 134

3.75 3.85 1.47 3.56

135 337 354

Bn

Daily [kWh/m2]

3.73 3.83 1.46 3.81 3.91 1.49 3.73 3.82

40.5 104.3 107.9 40.8

hourly [Wh/m2h]

Daily [kWh/m2]

Monthly [kWh/m2]

107.6 110.3 42.1 104.2 109.4

112.1 42.8 108.8 111.3 42.5Monthly

[kWh/m2]

108.5 111.4 42.5 109.3

2.1% 5.9% 7.5% 5.1% 13.9% 14.2% 4.8% 14.5% 25.2%

3.6% 9.3% 9.6% 3.7% 9.1% 6.3% 4.2% 12.0% 13.8%-80%

-60%

-40%

-20%

0%

20%

40%

60%

80%

Global irradiation Beam irradiation Diffuse irradiation

SolarGis Helioclim3 Solemi Heliomont CM-SAF IrSOLaV

hourly

mon

thly

daily

All-weathermodelvalidation


Validationresults

ð Gh:nearnormalbiasdistributionaroundthe1:1axis->reliablestatistics

ð Bn:nonnormalhighdispersion,thestandarddeviation

ð similarbehaviorforallthemodelswiththeclearnessindexKt

ð Model/measurementscomparablemonthlydispersion

Validationresults


Validationresults

ð Coherentfrequencydistributionfortheglobal

ð exceptforDavos(snow)

ð Randompatternforthebeamclearnessindexfrequencydistribution

ð 94%oftheglobaland83%ofthebeammonthlyvaluesarewithinonemeasurementsstandarddeviation

Validationresults


Validationresults

ð helioclim 3v4:poorclearskymodeltakenintoaccountinthefinalmodel,correctedinhc3v5

ð betterresultswithdailyinputparametersinsteadofmonthlyclimaticdatabanks

ð BettersnowmanagementinHeliomontandSolarGis

Validationresults


All-weathermodelvalidation


Interannualvariability

Histogramsoftheannualtotal


Interannualvariability

Allsitesoverallstatistics:systematicbiascomparedtotheinterannualvariability

ð Gh:allreal-timemodelswithinonemeasurementsstandarddeviation

ð Gh:TMY:2/6modelswithinonemeasurementsstandarddeviation

ð Bn:exceptSolemi,allmodelswithinonemeasurementsstandarddeviation

PVG

IS-CMSAF

WRD

C(198

1-19

93)

RetScreen(1

961-19

90)

NAS

A-SSE(198

3-20

05)

MN

7 (1

980-

2000

)

ESRA(198

1-19

90)

Satellight(1

996-20

00)

SolarGis(20

04-201

1)

Helioclim(2

004-20

11)

Sol

emi (

2004

-201

1)

Heliomon

t(20

06-201

1)

CM

-SA

F (2

004-

2011

)

IrS

OLa

V (2

006-

2011

)

NAS

A-SSE(198

3-20

05)

MN

7 (1

980-

2000

)

Satellight(1

996-20

00)

SolarGis(20

04-201

1)

Helioclim(2

004-20

11)

Solem

i(20

04-201

1)

Heliomon

t(20

06-201

1)

CM-SAF

(200

4-20

11)

IrSO

LaV(200

6-20

11)

SitesAlmeria 1850 2.5% 1.8% -8.1% -8.1% -3.0% 4.9% 0.4% 6.1% 3.0% 3.2% -0.1% 0.3% 2126 5.5% -3.8% -11.1% 15.1% -1.9% 12.1% -3.0% 6.3% 2.0% -3.9%Bratislava 1176 2.9% 3.2% 1.0% 1.1% -1.0% 1.7% 4.3% -3.5% 3.2% -0.2% 5.4% 2.8% 6.5% 4.4% 1191 7.4% -4.0% -7.5% -11.9% -9.6% -2.1% -21.8% -15.3% 3.5% 9.1%Carpentras 1587 2.1% 2.5% -4.8% -15.0% -6.0% -2.8% -5.4% 0.4% 0.3% 0.6% 2.7% 1.6% 2.1% 1.2% 1884 4.1% 0.4% -10.1% 4.9% -1.8% -0.3% -4.2% 3.0% 4.4% -1.6%Davos 1383 1.3% -0.8% -2.7% -7.9% 2.1% -2.9% -17.5% -4.2% 11.5% -13.2% -4.4% -14.5% -7.1% 1420 8.4% -8.0% 18.1% -26.2% -2.8% 21.9% -33.6% -9.5% -27.0% -36.9%Geneva 1282 2.3% 3.5% -6.3% 0.1% 0.1% -4.9% -5.5% -0.6% 4.2% 0.1% 6.4% 3.5% 4.1% 5.3% 1274 3.3% 4.3% -9.8% -0.9% 7.0% 1.9% -4.2% 8.6% 9.4% 4.0%Kassel 1048 2.7% 0.6% -5.6% -5.6% -5.8% -6.6% -5.9% -0.1% -3.4% 0.8% -2.9% -1.4% 4.0% 874 6.4% 1.0% -7.9% -5.1% 2.0% 10.2% -19.4% -4.4% 7.4% 21.8%Lerwick 810 4.7% -4.3% 9.2% 9.1% -3.5% -4.4% -2.5% 0.7% 5.4% 3.8% -3.2% -5.5% 580 13.3% 55.5% 18.2% 0.8% 6.9% 50.4% -11.5% 21.6% 8.5%Lindenberg 1120 3.8% -3.7% -3.8% -3.8% -9.8% -3.9% -12.3% -4.5% -3.1% -2.1% -3.5% -4.8% -0.5% -0.4% 1026 9.6% -8.1% 1.4% -0.4% -6.4% 5.8% -27.9% -15.1% 2.6% 30.5%Madrid 1697 4.9% 3.5% -5.2% -5.2% -3.1% -2.5% 1.7% 1.4% 4.4% 5.7% 5.6% 3.4% 1.9% 1798 5.2% 10.0% -0.8% 14.1% 5.4% 8.6% 4.8% 16.4% 11.0% -2.3%Nantes 1266 3.4% 1.5% -5.2% -3.4% -6.7% -2.2% -0.9% -2.7% -3.3% 0.4% 3.3% 0.7% -0.2% 1.3% 1307 6.7% -12.1% -9.6% -8.8% -8.4% 2.7% -11.1% 4.2% 0.6% 0.7%Payerne 1278 2.4% 1.7% -8.4% -2.5% 0.4% -1.9% -8.3% -2.8% 0.7% -6.4% 1.8% -0.1% -0.3% 4.8% 1191 4.4% 11.1% 5.9% 2.0% 7.0% -3.4% -5.8% 6.1% 7.5% 12.5%SedeBoqer 2114 1.2% -9.2% 0.5% -6.7% -3.9% -4.0% 0.6% -6.1% 3.4% 4.7% 0.9% -1.7% 2382 3.6% 4.6% -5.4% -4.6% -16.9% -8.7% -3.1% -4.8% -7.8%Tamanrasset 2345 1.8% -2.8% 0.8% 2.6% -8.1% 0.9% -1.2% 2.1% -1.8% -1.0% 0.0% 2355 4.0% 6.1% 18.1% 2.5% 14.7% -10.5% -9.2% 6.3%Toravere 981 3.8% 3.1% 3.1% -0.1% 4.6% -2.3% 2.1% -1.5% -4.4% -6.3% -0.8% 1028 8.8% 8.4% 2.4% 7.2% -6.5% 7.2% -28.4% -14.3% -11.7% 1.9%Valentia 1021 4.6% 9.4% -3.9% -4.8% 8.0% -5.3% -4.7% -4.2% -3.6% 4.1% 3.2% 1.8% -5.1% 1.4% 992 13.4% 10.7% -21.5% -21.3% -21.6% 3.3% -25.1% -2.3% -20.1% 1.9%Vaulx-en-Velin 1304 4.4% 3.4% -7.8% -4.0% -3.0% -6.3% -3.3% 0.4% 3.1% 2.6% 7.3% 5.9% 5.0% 3.6% 1359 5.3% -2.1% -11.6% -0.5% -0.9% 4.2% -4.7% 10.1% 7.9% -0.5%Wien 1175 2.7% 0.5% -6.8% -6.0% -0.8% 1.0% -7.0% -1.4% -0.3% -3.0% 3.4% 0.4% 2.7% 0.7% 1112 8.0% 2.9% -3.1% -2.5% -2.3% 4.0% -12.7% -3.5% 11.3% 15.0%Zilani 1024 3.3% -6.1% -3.2% 2.5% -2.6% 6.0% -1.4% 10.9% -3.2% -2.6% -5.9% -17.6% 1000 9.1% 13.4% -0.1% 20.5% -0.2% 31.9% -26.5% -7.3% -5.5% -13.6%

Allsites 1359 2.9% 0.1% -3.5% -3.5% -3.3% -2.3% -4.5% -1.6% -0.1% 1.4% 1.8% 1.0% 0.1% 0.5% 1383 6.3% 3.8% -1.6% -0.1% -1.6% 5.9% -11.3% 0.1% 1.9% -0.4%

3.4% 4.0% 5.1% 5.1% 3.0% 5.1% 3.9% 1.7% 3.9% 3.9% 2.9% 2.7% 3.0% 7.5% 9.3% 9.5% 4.8% 10.0% 12.0% 7.8% 7.5% 7.8%

4.6% 4.6% 6.5% 6.3% 3.4% 5.7% 5.9% 2.1% 5.1% 4.8% 3.6% 3.7% 4.2% 9.0% 11.9% 13.2% 5.9% 13.9% 14.5% 9.3% 9.1% 12.0%

mbd higherthantwostandarddeviationsmbd withinonestandarddeviation

Beamirradiation,meanbiasdifferencembdYearlyto

tal[kW

h/m2]

averageover2

004-20

10

standarddeviatio

nover2

004-20

10

Yearlyto

tal[kW

h/m2]

averageover2

004-20

10

standarddeviatio

nover2

004-20

10

Standarddeviationofmbd

Allsitesabsolutemeanbias

Globalirradiation,meanbiasdifferencembd

mbd withintwostandarddeviations


Publications:http://www.unige.ch/energie/fr/equipe/ineichen/

Thankyouforyourattention

clear sky and all-weather global and beam irradiance models: long term validation

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