The presentation is a detailed study on the following: a) Impact of solar module component on reliability b) Raw Material - Quality Assurance c) Manufacturing Process - Quality Assurance d) Lab Inspection e) On site module inspection

1. GENSOL CONSULTANTS PVT. LTD
www.gensol.in
PV Module Reliability & Quality Assurance

2. Significance of PV Modules Quality
Gensol Group
The lack of Quality Standards in the industry has a negative effect on the quality of modules being installed in
the country today. Different manufactures follows different methodology for quality process.
It is very important to know the quality standardization
process of solar PV modules for Developer, Investor, EPC &
O&M Contractor in solar industry as failure of modules with
lead to huge loss.

3. Solar PV Module Performance Curve
Gensol Group
The performance of solar PV module in various phases follows the bathtub shaped curve.
Fraunhofers Photovoltaic Durability Initiative Reducing Investment Risks, 2013 Defects Observed in PV Solar modules, Mike Rycroft(EE Publishers), 2016
IEA PVPS 2014

4. Impact of Solar Module Components on Reliability
Gensol Group
Ethyl Vinyl Acetate (EVA) sheets or solar EVA encapsulant are one of the most important components of the solar
module and are responsible for its long-term reliability and performance
Source -Encapsulants: Cost vs. Reliability, Brij Foot care

5. Impact of Solar PV Module Failures in Energy Gen. & Cost
Gensol Group
Solar PV Modules
PV Investment Technical Rsik Management, Solar Bankability, 2017

6. PV Modules Quality Assurance Plan
Gensol Group
Implementing a Quality
Assurance Plan (QAP)
will efficiently diminish
the technology risk
associated with solar
investment. Robust
quality system needs to
be in place for
performing vigorous
material level
evaluation, production
process and post
manufacturing module
level reliability
evaluation.
Reliability
Comes From
Quality
Assurance
Quality
Assurance
Testing
Pre/During
/Post
Process
Visual
Inspection
Proper
Measurem
ent
Service
Terms
Warranty
&
Guarantee

7. PV Modules Quality Assurance Plan
Gensol Group
Raw Material
Inspection
In Process
Inspection
Final
Inspection
Assurance
Inspection
Site
Inspection

8. Step I -Raw Material – Quality Assurance
Gensol Group
A) Glass
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Length Major Measurement Tolerance : ± 1 mm
Width Major Measurement Tolerance : ± 1 mm
Thickness Major Measurement 3.2 mm ± 2 mm
Transmitivity Major
Indirect
Measurement
Normal ≥ 91.5% and
Coating
Impact Resistant Major Testing (Impact Tester) Not broken
Appearance Major Visual
1. Scratch L ≤ 50 mm, W ≤ 0.5mm
allowed one, slight scratch do not
limit
2. Air bubble: width≤ 0.5mm
length ≤ 50mm, n≤ 4/square meter
0.5mm ≤ width ≤ 1mm, length ≤
30mm, n ≤ 1/square meter
3. Glass should be clarity and clean.
Cleaning of the glass surface done
using the rag with alcohol to wipe,
Type of Check Evaluation Technique
Measurement Steel ruler, angle ruler, stopwatch
Electronic scale
Testing
Thermometer, moderator Hygrometer
pull-force meter, Safety testing machine,
Power tester, Illuminance meters
Visual visual inspection
Note –The inspection processes represented here for solar PV quality assurance & its reliability are taken from various module manufacturer’s
QAP and other sources

9. Step I -Raw Material – Quality Assurance
Gensol Group
B) EVA
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Thickness Major Measurement ≥ 0.03mm
Dimensions Major Measurement Tolerance: 0-5mm
Gel content Major Testing 75% - 95% or 8 mm
Peel strength
between
Glass with EVA
Critical Testing ≥ 60 N/cm
Peel strength
between EVA with
back sheet
Critical Testing ≥ 40 N/cm
Shrinking Major Testing TD < 2%, MD < 4%
Volume resistivity Major Testing ≥ 6× 10e14 Ω-cm
Appearance Minor Visual
No dust and other foreign material;
no breakage;
no stain

10. Step I -Raw Material – Quality Assurance
Gensol Group
C) Back sheets
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Thickness Major Measurement 0.18-0.235 mm
Length Major Measurement Tolerance: ± 0.5mm
Width Major Measurement Tolerance: ± 0.5mm
Back busbar width Major Measurement
Accoding to drawing of cell
Front busbar width Major Measurement
AJ-BSF Adhensive Major Testing ≥ 10 N/cm
EL Major Testing
No microcrack, pollution
Power Critical Measurement Average power (0- +3% ×
nominal power)
Appearance Major Visual
No visible cells crack, cells broken,
any extended V shape
notch are not allowed

11. Step I -Raw Material – Quality Assurance
Gensol Group
D) Solar Cells
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Thickness Major Measurement 0.18-0.235 mm
Length Major Measurement Tolerance: ± 0.5mm
Width Major Measurement Tolerance: ± 0.5mm
Back busbar width Major Measurement
Accoding to drawing of cell
Front busbar width Major Measurement
AJ-BSF Adhensive Major Testing ≥ 10 N/cm
EL Major Testing No micro-crack, pollution free
Power Critical Measurement
Average power (0- +3% ×
nominal power)
Appearance Major Visual
No visible cells crack, cells broken,
any extended V shape
notch are not allowed

12. Step I -Raw Material – Quality Assurance
Gensol Group
E) Ribbon
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Thickness Major Measurement
Cell connector- Tolerance: ± 0.01mm
String connector- Tolerance: ± 0.01mm
Width Major Measurement
Cell connector- Tolerance: ± 0.05mm
String connector- Tolerance: ± 0.05mm
Soldering strength Critical Testing ≥ 1.5 N/mm
Coating thickness Major
Visual (check the report
provided by supplied)
0.025mm ± 0.005mm (single side)
(check supplier outgoing report)
Appearance Major Visual
Flatness, no stain, no deformation,
no crystal, no coating-missing
Thickness Major Measurement
Cell connector- Tolerance: ± 0.01mm
String connector- Tolerance: ± 0.01mm
Width Major Measurement
Cell connector- Tolerance: ± 0.05mm
String connector- Tolerance: ± 0.05mm
Soldering strength Critical Testing ≥ 1.5 N/mm
Coating thickness Major
Visual (check the report
provided by supplied)
0.025mm ± 0.005mm (single side)
(check supplier outgoing report)
Appearance Major Visual
Flatness, no stain, no deformation,
no crystal, no coating-missing

13. Step I -Raw Material – Quality Assurance
Gensol Group
F) Anodized Al Frames
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Width Major Measurement Tolerance: ± 0.5mm
Length Major Measurement Tolerance: ± 0.5mm
Mounting hole pitch Critical Measurement Tolerance: ± 0.5mm
Drain hole distance Major Measurement
60 mm ± 0.5mm
Angle Major Measurement
45˚± 0.25˚
Hardness Major Measurement ≥ 8 hw
Coating thickness Major Measurement ≥ 15um
Appearance Major Visual
same color, no water stain, oil
stain,
contamination, scratch,
coating film no broken

14. Step I -Raw Material – Quality Assurance
Gensol Group
G) Junction Box
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Cable length Major Measurement Actual length ± 13mm
Dimensions Major Measurement According drawings
Electrical performance Major Measurement Contact resistance ≤ 10 mohms
Appearance Major Visual
1. Diode polarity, quantity is right,
terminal should be complete
2. No damage
H) Sealant
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Manufactured date Major Visual Within 12 months after manufacturing
Expiry date Major Visual 12 months
Batch No. Major Visual Within 12 months after manufacturing
Appearance Major Visual No bubble, smooth, thick liquid,
no damage package

15. Step I -Raw Material – Quality Assurance
Gensol Group
I) Flux
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Manufactured date Major Visual
Within 6 months after
manufacturing
Expiry date Major Visual 6 months
Batch No. Major Visual
Within 6 months after
manufacturing
Appearance Major Visual Transparent, Colourless
J) Label
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Label parameters Major Visual
Module type, Pmpp, Voc, Isc, Vmpp, Impp,
Series fuse rating, Tolerance of Pmpp,
Weight, Dimension STC, Measuring
uncertainty of power
Dimensions Major Measurement Tolerance: 5-1 mm
Appearance Major Visual
No flaw, mildew, dirty, delamination,
hole obvious defect by naked eye not
allowed

16. Step I -Raw Material – Quality Assurance
Gensol Group
G) Palet
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Dimensions Major Measurement Tolerance: 5-1 mm
Appearance Major Visual
No flaw, mildew, dirty, delamination,
hole obvious defect by naked eye not
allowed
H) Package
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Dimensions Major Measurement Tolerance: 5-0 mm
Appearance Major Visual
No broken, right painting
Printing Major Visual

17. Step II - Manufacturing Process –Quality Assurance
Gensol Group
Solar Cells Solar Scribbling Soldering
EVA & back sheet
cutting
Laying
Lamination Framing EL Check IV Test Cleaning
Packaging

18. Step II - Manufacturing Process –Quality Assurance
Gensol Group
A) Sorting of Cells
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Appearance Major Visual/Manually
Colour conformity or jumping colour in
one module, No north, No V-type defect,
No crack, No broken
B) EVA & Back Sheet Cutting
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
EVA supplier Major Visual
According to the BOM of production plan
Supplier and Type are right
EVA expiry date Major Visual 6 months
Uneven cutting Major Visual Not allowed
Length of the EVA &
Backsheet
Major Measurement
EVA: +2MM
Backsheet: ± 1mm

19. Step II - Manufacturing Process –Quality Assurance
Gensol Group
C) Cell Assembling
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Check materials Major Visual
According to the BOM of production plan supplier and
type are rightCells supplier Major Visual
Flux supplier Major Visual
Expiry date of flux Major Visual 6 months
D) Soldering
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Ribbon adhesion with
busbar and Tin covering
area
Major Measurement Ribbon Adhesion with busbar ≥ 1.5Nmm
Tin covering area ≥ 85%
Manual line:
Iron temperature
Major Measurement
0.2mm (Ribbon thickness) 320˚ - 350˚
0.23mm (Ribbon thickness) 330˚ - 360˚
0.25mm (Ribbon thickness) 340˚ - 370˚
Automatic soldering
temperature
Major
Visual(check the setting
temperature with the
standard temperature)
Temperature 180˚ - 210˚
Ribbon adhesion with
busbar and Tin covering
area
Major Measurement Ribbon Adhesion with busbar ≥ 1.5Nmm
Tin covering area ≥ 85%
Time Control Major Measurement 3-5 sec

20. Step II - Manufacturing Process –Quality Assurance
Gensol Group
E) Ribbon
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Check interconnector (connect
the cells) materials as BOM
Major Visual
According to the BOM of production plan
Supplier and size is right
Check the cross connector
(connect the termination)
Major Visual
According to the BOM of production plan
Supplier and size is right
Appearance Major Visual
Flatness, no stain, no deformation,
no crystal, no coating-missing
F) Lay -Up
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
String misaligned Major Measurement ± 0.3mm
Foreign materials Major Visual Not allowed
EL Test Major Testing According to the EL inspection standard

21. Step II - Manufacturing Process –Quality Assurance
Gensol Group
G) Lamination
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Bubbles Major Visual
S ≤ 2mm (on the cell), ≤ 1pcs
S ≤ 3mm (out of the cell), ≤ 2pcs
String merged Major Visual Not allowed
Delamination Major Visual Not allowed
Foreign materials Major Visual As per plant standard
Temperature Major Testing Tolerance ± 3 degrees according to EVA property
Vacuum Major Testing <-99.5kpa
Gel content Major Testing 75% - 95%
Peel strength test Major Testing
Back plate with EVA ≥ 60 N/cm
Glass with EVA ≥ 40 N/cm
H) Framing & Crimping
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Comer Gap Major Visual ≤ 0.5mm
Vertical Gap Major Visual ≤ 0.5mm
Diagonal Difference Major Visual
Diagonal ≤ 1m, Diagonal difference ≤ 2mm
Diagonal > 1m, Diagonal difference ≤ 3mm
Pressure Major Visual
The presence of the framing machine is
0.6-0.7Mpa
Comer Crimping Major Visual Polish & smooth

22. Step II - Manufacturing Process –Quality Assurance
Gensol Group
I) JB Fixing & Potting
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Check junction box, fixing
and potting materials
Major Visual Supplier and type are right
Check for JB soldering
temperature
Major Visual 380˚ - 400˚
J) Cleaning & Labelling
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Appearance Major Visual
According to the Manufacturers
Inspection Standard for modules
Label fixing Major Visual

23. Step III- Final Product In Lab Testing
Gensol Group
Source- TUV Rhineland,

24. Step III- Final Product - In Lab Testing
Gensol Group
A) Thermal Cycling
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Solder bond or ribbon
failure, usually
associated with thermal
fatigue
Major Testing
This is an extension of IEC 61215 (200
cycles). Thermal cycling is known to identify
this failure; field and modelling studies imply
that longer testing may be beneficial.
-40° C to 85° C.
B) Dynamic Mechanical Load Test
Characteristics Class
Type of
Check
Acceptance Norms/
Tolerance
Cracked cells that
cause hot spots and
power loss
Major Testing
IEC 62782. Studies have shown that the
combination of DML and thermal cycling can
uncover this failure.
mechanical stress -1,000 cycles at
±1,000 Pa) followed by thermal stress (50
cycles of thermal cycling)
Source - PV Module Reliability, DNV GL, 2017

25. Step III- Final Product In Lab Testing
Gensol Group
D) Damp Heat Test
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Damp Heat Test Major Testing
In the IEC 61215, modules are held at
a constant temperature of 85° C and a
relative humidity of 85% for 1,000
hours (~42 days)
E) PID Test
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
PID Test Major Testing
Power loss for modules operating at
large (positive or negative) bias
voltage
Test method: IEC 62804
Source - Photovoltaic Module Qualification Plus Testing, 2013
C) Humidity Freeze test
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Humidity Freeze Test Major Testing
In the standard IEC 61215 test modules are exposed to
temperatures of 85° C and a relative humidity of 85% for a minimum
of 20 hours. The temperature is then rapidly dropped to -40° C for a
minimum of 30 minutes (maximum 4 hours), freezing any moisture
within the module & for 10 cycles.

26. Step III- Final Product In Lab Testing
Gensol Group
F) Appearance/Visual Inspection
Characteristics Class
Type of
Check
Acceptance Norms/
Tolerance
• Colour of cell,
• Snail trails,
• Bubble,
• Foreign
material,
• Serial number,
• Back sheet,
• Glass,
• Frame
• Junction box
Major Visual
a) No broken, cracked, or tom external surfaces including
superstrates, substrates, frames and junction boxes.
b) No bent or misaligned external surfaces, including
superstrates, substrates, frames and junction boxes to the
extent that the installation and/or operation of the module
would be impaired;
c) No voids in, or visible corrosion of any of the thin film
layers of the active circuity of the module, extending over
more than 10% of any cell;
d) No bubbles or delamination forming a continuous path
between any part of the electrical circuit and the edge of
the module;
e) No loss of mechanical integrity, to the extent that the
installation and/or operation of the module would be
impaired;
f) Module markings(label) is no longer attached or the
information is unreadable.

27. Step III- Final Product In Lab Testing
Gensol Group
G) Dimensions
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Length, width, diagonal
difference & label fixing
Major Measurement
Length, width ± 1mm
Diagonal ≤ 1m, Diagonal difference ≤ 2mm
Diagonal > 1m, Diagonal difference ≤ 3mm
H) Insulation Resistance
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Insulation resistance Major Testing
Module area > 0.1 square meter,
≥ 40Mohm.mm2
Module area < o.1 square meter,
≥ 400 Mohm
I) Hi Pot
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Hi-pot test Major Testing ≤ 50 µA

28. Step III- Final Product - In Lab Testing
Gensol Group
J) Grounding Continuity
Characteristics
Class Type of Check
Acceptance Norms/
Tolerance
Grounding continuity test
Major Testing ≤ 100 mΩ
K) Flash Test & IV Data Measurement
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Electrical data measurement of
vmp, imp, pmax, voc, isc, shunt
resistance, series resistance,
etc.
Major Testing
As the Technical specification;
1) Calibration on Board power than 0.1% of
nominal value
2) Test power on board than 0.3% of nominal
value
L) Electroluminescence Testing
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Brightness, Black finger, cross
crack, Shadow, Black Area, or
invalid cell, irregular crack
concentration, material
pollution,
wrong cell printing
Major Testing
EL defect of any of the thin film layers of
the active circuitry of the module
extending over more than 10% of any cell.
Total power loss of the module less than
5%. Testing I-V curve is not abnormal

29. Step III- Final Product - In Lab Testing
Gensol Group
M) Wet Leakage Test
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Wet leakage test Major Testing ≤ 50 µA
N) Impulse Voltage Test
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Impulse voltage test Major Testing IEC 61730-2:2004
O) Packaging & Marking
Characteristics Class Type of Check
Acceptance Norms/
Tolerance
Impulse voltage test Major Visual
Road and sea worthy packaging as every sales market
condition

30. Step IV – Assurance Inspection
Gensol Group
Assurance
Inspection
includes two
principles:
"Fit for purpose"
(the product
should be
suitable for the
intended
purpose);
"right first time"
(mistakes should
be eliminated).
For Assurance Inspection, same sets of tests are being performed as performed during manufacturing process. The final
testing process prior to deployment and is performed by a company tester who ultimately signs off on the product
Safety test
(Safety testing
machine)
Test condition
Withstand voltage test: voltage 3600V, the
upper limit of current 50µA,rising voltage 8S,
test 1S
Property
After a single test, Fail light or the instrument
appear bazzar alarm means unqualified

31. Step V – On Site Module Inspection
Gensol Group
Visual Inspection.
Electroluminescence Test
(prior and after installation
on structure)
Maximum Power
determination at STC
(module and arrays).
PV String - Voc and Isc
Measurement.
IR Thermography
Inspection of modules
(ground and drone
inspections) and electrical
connection,
Verification of Diodes
Operation.
Voltage Drop
Measurement .
Polarity Verification Tests.
Insulation Resistance
Measurement
Grounding Resistance
Measurements
Audit of Monitoring
System & Weather Stations

32. Step V – On Site Module Inspection
Gensol Group
Aerial inspections (from drone or airplane) of PV power
plants are being conducted nowadays for defective or
underperforming modules and strings which are able to
detect module-level defects which cause temperature
differences in the module such as diode faults, cell hot-
spots, junction box heating and major differences in module
efficiency.
Source: Heliolytics, “Summary of DC Losses
Observed using Aerial Infra-Red Inspection Across
>1.6 GW”, Rob Andrews and Kristine Sinclair, 2017

33. Assurance Compliances or Testing Specification
Gensol Group
Compliances Comply with
IEC 61215 (Edition
2005)
Crystalline silicon terrestrial photovoltaic (PV) modules -
Design qualification-Performance Standards
IEC 61646 Thin-film terrestrial photovoltaic (PV) modules - Design
qualification -Performance Standards
IEC 61730 Module safety Qualification – Safety Standards
UL 1703 Fire classification rating
ISO 9001:2008 Module manufacturing unit Quality compliances
ISO 14001 Environmental Management System Certification
OHSAS 18001 Occupational health and Safety
IEC 60891 PV - Procedures for temperature and irradiance corrections to
measured I-V characteristics
IEC 61701 Salt mist corrosion testing
IEC 62716 Ammonium corrosion testing
IEC 60364 Protection Against Electric Shock for low-voltage electrical
installations in PV modules
IEC61646 or
IEC61625-
Wet Leakage Test to test the electrical isolation of the
housing
ASTM E1171 - 15 Test Methods for Photovoltaic Modules in Cyclic
Temperature and Humidity Environments
IEC 60904 Measurement of current-voltage characteristics of bifacial
photovoltaic devices
IEC 60721 PV module’s performance capability under prolonged
exposure to standard climates
IEC60068-2-2 Test to evaluate the ability of the module for use/storage
under high temperature
IEC 61853 Validation of Models using Outdoor Test Methods
IEC TS 62782 test method for performing a cyclic (dynamic) mechanical
load test
IEC TS 62804-1:2015 Test to evaluate the durability of crystalline (PV) modules to
the effects of short-term high-voltage stress including
potential-induced degradation (PID)

34. About Gensol
Solar Advisory Services Solar EPC Services Solar O&M Services
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Gensol Group
Gensol provides concept to commissioning solar advisory, execution and operations services for Solar Projects in India and abroad.
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Evangelist
+91 7698833311
anmoljaggi@gensol.in
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Head of Strategic Advisory
& Business Development
+91 9327016962
imrannaqvi@gensol.in
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Head of Engineering &
Operations
+91 9725544301
gurpreetsingh@gensol.in
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Director
+91 9998025820
puneetjaggi@gensol.in
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President
+91 9850673664
pranaymundra@gensol.in
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Head of Supply Chain & Group
CFO
+91 9376703846
shivyasinghal@gensol.in
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35. Gensol is one of the leading consultants and system integrators for Solar Power Plants. We boast of a portfolio of over 6000 MW of Solar Photovoltaic Plants. Gensol is also a channel
partner to Ministry of New & Renewable Energy and installs kW scale Solar Rooftop systems on a turnkey basis with more than 42 MW of cumulative installations across the country.
The information contained herein is of a general nature and is not intended to address the circumstances of any particular individual or entity. Although we endeavor to provide
accurate and timely information, there can be no guarantee that such information is accurate as of the date it is received or that it will continue to be accurate in the future. No one
should act on such information without appropriate professional advice after a thorough examination of the particular situation.
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