1 PV essentials from standards to testing
12 Years experience on PV module testing- testing Services -
TÜV Rheinland Group
C.DreierTÜV Rheinland JapanPhotovoltaicEnergy and Environment TechnologyIndustrial ServicesTel.:+ 81 45 914 [email protected]
W.Vaassen, W.Herrmann, J.Althaus, TÜV Immissionsschutz und Energiesysteme GmbHAm Grauen Stein, 51105 Köln, GermanyTel.:+ 49 221/ 806 2870, Fax + 49 221/806 1350
2 PV essentials from standards to testing
�Facilities
• TÜV Rheinland, Cologne
• TÜV Rheinland Japan, Yokohama
• TÜV Rheinland Shanghai, Shanghai
• TÜV Rheinland North America, Phoenix
• TÜV Rheinland Taiwan, Taipei
3 PV essentials from standards to testing
�Type approval qualification of Photovoltaic-ModulesStandards
EN IEC 61215 (1993): Crystalline silicon terrestrial photovoltaic (PV)
modules – Design qualification and type approval
IEC 61215 (2005): Crystalline silicon terrestrial photovoltaic (PV)
modules – Design qualification and type approval
Edition 2
IEC 61646 (2008): Thin-film terrestrial photovoltaic (PV) modules –
Design qualification and type approval
Edition 2
IEC 61730 (2004): Photovoltaic (PV) module safety qualification
- Part 1: Requirements for construction
- Part 2: Requirements for testing
4 PV essentials from standards to testing
Visual Inspection, Performance, Insulation, Wet leakage
� IEC 61215, Ed. 2 (April 2005) Crystalline silicon terrestrial PV modules - Design qualification and type approval
Preconditioning (5 kWh/m²)
Thermal cycling(200 cycles)
ElectricalParameters
OutdoorTest
Bypass Diode Test
Hot-Spot Test
UV preconditioning
Thermal cycling(50 cycles)
Humidity freezeTest
TerminationsTest
Damp Heat Test
Hail Test
Mech.Load
Visual Inspection, Performance, Insulation, Wet leakage
5 PV essentials from standards to testing
Visual Inspection, Performance, Insulation, Wet leakage
� IEC 61646, Ed. 2 (2008) Thin-film terrestrial PV modules - Design qualification and type approval
Thermal cycling(200 cycles)
ElectricalParameters
OutdoorTest
Bypass Diode Test
Hot-Spot Test
UV preconditioning
Thermal cycling(50 cycles)
Humidity freezeTest
TerminationsTest
Damp Heat Test
Hail Test
Mech.Load
Visual Inspection, Performance, Insulation, Wet leakage
Light soaking
6 PV essentials from standards to testing
� IEC 61215Pass Criteria
Extract from IEC 61215:
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�Measurement of modulesSteady state solar simulator
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�Measurement of modulesFlash type solar simulator (long pulse 800ms) AAA
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�Measurement of modulesspectral response equipment
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�Measurement of modulesFlash type solar simulator (3m x 3m surface AAA (<1% uniformity))
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�Measurement of modulesFlash type solar simulator (3m x 3m surface AAA (<1% uniformity))
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�Outdoor Test
Outdoor exposure dose:
60 60 kWh/mkWh/m²²NOCT:
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�Bypass diode thermal testPossible problem in field installation
3,8°C
37,0°C
10
20
30
Active by-pass diode (closed connection box)
24,7°C
84,1°C
40
60
80
Active by-pass diode (connection box with open lid)
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�Bypass diode thermal testExample of test performance
38,0°C
163,0°C
40
60
80
100
120
140
160
Diode type: 80 SQ 045 Tj max = 175°C
CurrentCurrentCurrentCurrent[A][A][A][A]
Box Temperature[[[[°°°°C]C]C]C]
Junction TemperatureJunction TemperatureJunction TemperatureJunction TemperatureTTTTJJJJ [ [ [ [ °°°°C]C]C]C]
4.88 (ISC) 128.2 135.2
6.1 (1.25*ISC) 144.2 151.2
15 PV essentials from standards to testing
�Hot-Spot endurance testProblem
Cell Voltage
Cell Current
Reverse-Voltage
Module Current
Forward-Voltage
Forward-Voltage
Solar-cellIV-curves
ReducedIrradiationIrradiation
Infraredimages
16 PV essentials from standards to testing
�Hot-Spot endurance testTest failure
182 °C
326 °C
200
250
300
Hot-Spots can produce severe visible defects on module front and rear side (temperatures > 300 °C !)
17 PV essentials from standards to testing
�UV-preconditioning testTÜV test chamber Browning effects of EVA
- Dose UV (280 nm - 400 nm): > 15 kWh/m²
- Dose UV-B (280 nm - 320 nm): =3 to 10 % of total UV
- Module temperature: 60 °C
18 PV essentials from standards to testing
�Climatic-TestsTÜV test facilities
19 PV essentials from standards to testing
�Climatic-TestsThermal cycling test
200 (50) temperature cycles from -40 °C to 85 °C
Edition 2:
Current flow (IMPP ± 2%) through modules (t > 25 °C)
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�Climatic-TestsHumidity-Freeze test
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�Climatic-TestsDamp heat test
Test temperature: 85 °C ± 2 °C
Relative Humidity: 85% ± 5%
Test duration: 1000 hours
Module temperature/ °C
Time / h
85
0 500 1000
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�Climatic-TestsTest failures I: Module delaminations
23 PV essentials from standards to testing
�Climatic-TestsTest failures II: Boxes and connectors
Crumbled junction box
Broken and shrunken plugs
Crumbled junction box
Zinc dust
24 PV essentials from standards to testing
�Climatic-TestsTest failures III: Solar cells
Corrosion of cell interconnector
Cracking of cells
Shifting ofcells
Cell delamination
25 PV essentials from standards to testing
�Climatic-TestsTest failures IV: Other
Browning of string-connector
Shrinking of foil
Come off of the foil
Glass-corrosion
26 PV essentials from standards to testing
�Climatic testsTest failure – IV-curves
Reduction of Fill-Factor due to increasement of series resistance
Power loss of strings due to interrupted interconnects
27 PV essentials from standards to testing
�Climatic testsDamp Heat test, test experience last 5 years
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�Mechanical load testTest performance
3 load-tension cycles:
2400 Pa, 1 hour
Optional: 5400 Pa
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�Mechanical load testTest failures
30 PV essentials from standards to testing
�Hail impact testTest performance
Hail impact shots on 10 different locations:
Iceball speed: 23 m/s
Iceball diameter: 2.5 cm
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�Light soakingTÜV test facilities
32 PV essentials from standards to testing
�Summary Test statistic
Measurement of different PV- module typestest results (last 8 years)
0 20 40 60 80 100
%
All Tests
Passed
Fault
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�Summary Test statistic of new certification processes
Failure, Module typenot accepted
Certificationwithout anyproblems
Certification with problems(Repeat of tests)
30 %20 %
50 %
34 PV essentials from standards to testing
� Test failuresHow to continue?
• If the test samples fail in several different qualification tests (i. g. damp-heat, thermal-cycling and hot-spot) we have to reject the complete module design!
The manufacturer can then reapply with an improved design.
• If one qualification test is failed, the following procedure applies:
• The failed test sample(s) will be shipped back to the manufacturer for investigation.
• The manufacturer provides us with a detailed failure analysis report:
• What exactly was the reason for the failure?
• What measures will be taken to avoid such failures?
• With this evaluation report at hand, TÜV decides what tests have to be repeated with new test samples.
• If the repetition of the selected tests is passed, TÜV will issue the certificate.
If the test-repetition is failed again, the module design has to be rejected!
35 PV essentials from standards to testing
�SummaryConclusion
• Although PV-modules have reached a sophisticated level of technology, a lot of different test-failures occur in laboratory testing
• Manufacturing a PV-Module that is able to pass all qualification tests is a difficult task. All materials, components and process parameters
have to be chosen carefully.
• Even small design changes can effect the suitability of the module design and therefore may require a retesting program to maintain type
approval certification.
36 PV essentials from standards to testing
Thank you for your kind attention
If you have additional questions:Christian Dreier,
TÜV Rheinland JapanPhotovoltaicEnergy and Environment TechnologyIndustrial ServicesTel.:+ 81 45 914 3888