Solar testing in climate chambers Stefan Roest Technical director
Costs are not the issue anymore... improving reliability is key. Gujarat, India 2
Testing PV modules IEC 61215 & 61646 Performance testing Weathering Accelerated Life testing 3
+ + In one test setup Performance testing Weathering Accelerated life testing 4
Reliability testing of CIGS cells Copper Indium Gallium Selenide/sulfur: Cu(In,Ga)(Se,S) 2 In, Ga Se, S 5
CIGS solar cells/modules i-zni / ZnO:Al window Buffer layer 3-5 micron CIGS absorber Mo back contact Glass substrate Source: Friedlmeyer 2010 6
Benefits of CIGS solar cells/modules High efficiencies (20.3%) Thin film solar cell (flexibility) Low cost ( /W p ) potential due to high efficiencies and low material usage (per m 2 module) Nice black colour makes it suitable for building integration 7
Main challenge Water is the biggest enemy in combination with light and electrical loads. 8
How to find weaknesses Loads Temperature Moisture Light Electrical load Place a CIGS cell or mini-module under one or more loads In-situ measuring of degradation of In-situ measuring CIGS cells of degradation of CIGS cells Removal of cells from setup when they break down Chemical analysis of the cells before and after degradation: XRD, XPS, SEM- 9
The test setup 10
The test setup Eternal Sun climate chamber solar simulator Solar simulator 80 x 80 cm 2 Climate chamber For damp heat treatment Window shutter For dark curves 11
The samples - A non-degrading metal is used as contact Four point probe connection Contacts Single cell with silver contacts Mini-module with gold contacts 12
Test layout 400 mm CIGS cells Thermocouple on every cell 400 mm Photodiode Interconnection Damp heat resistant 13
Vertical position [ mm ] Test layout: light uniformity < 2% CIGS cells 400 Measured Intensity [ W / m 2 ] 1025 350 1020 300 250 1015 200 1010 < 2 % Class A IEC 60904 (solar simulation standard) 150 100 50 1005 1000 995 0 0 50 100 150 200 250 300 350 400 Horizontal position [ mm ] 14
Current density (ma/cm 2 ) Efficiency (%) Open clamp voltage (V) Fill factor (%) Multiple cell parameter results 1 Open clamp voltage 70 Fill Factor 0.9 60 0.8 50 0.7 0 100 200 300 400 Time at 85C/85% RH (hours) 40 0 100 200 300 400 Time at 85C/85% RH (hours) 16 Current density 9 Efficiency 15 14 8 7 6 13 0 100 200 300 400 Time at 85C/85% RH (hours) 5 0 100 200 300 400 Time at 85C/85% RH (hours) 15
Efficiency (%) I sc (ma) V oc (Volt) Temperature dependency The setup can also be used to determine temperature dependency of many cell parameters 15 1,6 14 (abs): -0.06%/ o C 13 I sc : -0,006 ma/ o C 1,4 12 11 V oc : -4 mv/ o C 1,2 10 1,0 9 8 0 20 40 60 80 100 Temperature ( o C) 0,8 16
Summary AAA-accuracy solar simulation inside in climate chamber + + Improve PV reliability faster and easier 17
Thank you Stefan Roest sroest@eternalsun.com
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Eternal Sun solar simulation test procedures IEC 61215: Crystalline silicon PV modules Design qualification and type approval Eternal Sun Large area solar simulator scope Eternal Sun Climate chamber solar simulator additional scope 20
Eternal Sun solar simulation test procedures IEC 61646: Thin-film PV modules Design qualification and type approval Eternal Sun Large area solar simulator scope Eternal Sun Climate chamber solar simulator additional scope 21
About Eternal Sun The unique benefits of Eternal Sun products are: AAA-accuracy Any size Steady-state Company presentation 22
Large area solar simulator Performance and degradation testing AAA class steady-state or long pulse Suited for testing new module types & large sizes Flexible in use & operational in different angles Small footprint & turn-key 23
Climate chamber solar simulator Accelerated lifetime testing and weathering Sunlight, humidity and temperature cycling AAA class steady-state or long pulse sunlight inside climate chamber Computer controlled integrated system Turn key operation 24
In-line solar simulator In-line performance testing and inspection In-line, sunny side down testing One module every 10 seconds One second IV sweep for any module technology Production line tuning 25
Roll to roll solar simulator Roll to roll performance testing and inspection Roll to Roll PV testing Easy mounting of rolls of different sizes 1 module every 4 seconds 1 second IV sweep for any module technology 26
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