Bsi bs en 61646 2008 (2009)

BS EN 61 646:2008
Incorporating Corrigendum August 2009

BSI Standards Publication

Thin-film terrestrial photovoltaic
(PV) modules — Design
qualification and type approval


BS EN 61 646:2008

BRITISH STANDARD
National foreword
This British Standard is the UK implementation of EN 61 646:2008. It is identical to IEC 61 646:2008. It supersedes BS EN 61 646:1 997 which is withdrawn.
The UK participation in its preparation was entrusted to Technical Committee
GEL/82, Solar photovoltaic energy systems.
A list of organizations represented on this committee can be obtained on
request to its secretary.
This publication does not purport to include all the necessary provisions of a
contract. Users are responsible for its correct application.
© BSI 2009
ISBN 978 0 580 68994 9
ICS 27.1 60

Compliance with a British Standard cannot confer immunity from
legal obligations.
This British Standard was published under the authority of the Standards
Policy and Strategy Committee on 31 July 2009

Amendments issued since publication

Date

Text affected

31 August 2009

Correction to missing CENELEC pages


EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM

EN 61 646
August 2008

ICS 27.1 60

Supersedes EN 61 646:1 997

English version

Thin-film terrestrial photovoltaic (PV) modules Design qualification and type approval
(IEC 61 646:2008)
Modules photovoltaïques (PV)
en couches minces
pour application terrestre Qualification de la conception
et homologation
(CEI 61 646:2008)

Terrestrische Dünnschicht-Photovoltaik
(PV)-Module Bauarteignung und Bauartzulassung
(IEC 61 646:2008)

This European Standard was approved by CENELEC on 2008-06-01 . CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1 050 Brussels
© 2008 CENELEC -

All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61 646:2008 E


BS EN 61 645:2008

EN 61 646:2008

-2-

Foreword
The text of document 82/51 2/FDIS, future edition 2 of IEC 61 646, prepared by IEC TC 82, Solar
photovoltaic energy systems, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 61 646 on 2008-06-01 .
This European Standard supersedes EN 61 646:1 997.
EN 61 646:2008 includes the following significant technical changes with respect to EN 61 646:1 997:
The major change is in the pass/fail criteria. It no longer relies on meeting a plus/minus criterion before
and after each test, but rather on meeting the rated power after all of the tests have been completed and
the modules have been light-soaked. This was done to eliminate the technology-specific preconditioning
necessary to accurately measure the changes caused by the test. (Some modules lose power in light
while others lose power during dark heat.) Since all modules must work after exposure to light, this
seemed like a good approach and will streamline the test procedure, hopefully reducing the testing cost.
– updated normative references;
– added a definition of “minimum value of maximum output power”;
– modified the wording in major visual defects to allow some bending and misalignment without failure;
– added requirements to the report from EN ISO/IEC 1 7025;
– removed the “Twist Test” as was done from EN 61 21 5, since no one has ever failed this test;
– made the pass/fail criteria for insulation resistance and wet leakage current dependent on the module
area;
– added the temperature coefficient of power ( δ) to the required measurements;
– modified temperature coefficient section to allow for measurements under natural sunlight or a solar
simulator;
– deleted reference plate method from NOCT;
– added apparatus sections to those test procedures that did not have apparatus sections in
EN 61 646:1 997;
– rewrote the hot-spot test;

– eliminated edge dip method from wet leakage current test;
– changed mechanical load test to 3 cycles to be consistent with other standards;
– added bypass diode thermal test.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement

(dop)

2009-03-01

– latest date by which the national standards conflicting
with the EN have to be withdrawn

(dow)

201 1 -06-01

Annex ZA has been added by CENELEC.
__________


-3-

BS EN 61 646:2008
EN 61 646:2008

Endorsement notice
The text of the International Standard IEC 61 646:2008 was approved by CENELEC as a European

Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60904-5

NOTE Harmonized as EN 60904-5:1 995 (not modified).

IEC 60904-8

NOTE Harmonized as EN 60904-8:1 998 (not modified).

__________


BS EN 61 645:2008
EN 61 646:2008

-4-

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication
IEC 60068-1

Year
-1 )

IEC 60068-2-21

-1 )

IEC 60068-2-78

2001

IEC 6041 0

-1 )

IEC 60721 -2-1

-1 )

IEC 60891

-1 )

IEC 60904-1

2006

IEC 60904-2

-1 )

IEC 60904-3

-1 )

IEC 60904-7

-1 )

IEC 60904-9

-1 )

IEC 60904-1 0

-1 )

IEC 61 21 5

-1 )

1)
2)

Undated reference .
Valid edition at date of issue .

Title
EN/HD

Environmental testing EN 60068-1
Part 1 : General and guidance
Environmental testing EN 60068-2-21
Part 2-21 : Tests - Test U: Robustness of
terminations and integral mounting devices
Environmental testing EN 60068-2-78
Part 2-78: Tests - Test Cab: Damp heat,
steady state
Sampling plans and procedures for inspection by attributes
Classification of environmental conditions - HD 478.2.1 S1
Part 2-1 : Environmental conditions appearing
in nature - Temperature and humidity
Procedures for temperature and irradiance EN 60891
corrections to measured I-V characteristics of
crystalline silicon photovoltaic devices
Photovoltaic devices EN 60904-1
Part 1 : Measurement of photovoltaic currentvoltage characteristics
Photovoltaic devices EN 60904-2
Part 2: Requirements for reference solar
devices
EN 60904-3
Photovoltaic devices Part 3: Measurement principles for terrestrial
photovoltaic (PV) solar devices with reference
spectral irradiance data
Photovoltaic devices EN 60904-7
Part 7: Computation of spectral mismatch
error introduced in the testing of a photovoltaic
device
Photovoltaic devices EN 60904-9
Part 9: Solar simulator performance

requirements
Photovoltaic devices EN 60904-1 0
Part 1 0: Methods of linearity measurement
Crystalline silicon terrestrial photovoltaic (PV) EN 61 21 5
modules - Design qualification and type
approval

Year
1 994 2)
2006 2)
2001 2)
1 989 2)
1 994 2)
2006 2)
2007 2)
2008 2)

1 998 2)

2007 2)
1 998 2)
2005 2)


-5Publication
ISO/IEC 1 7025

Year
-1 )

BS EN 61 646:2008
EN 61 646:2008

Title
EN/HD
Year
General requirements for the competence of EN ISO/IEC 1 7025 2005 2)
testing and calibration laboratories


BS EN 61 646:2008
–2–

61 646

 I EC: 2008

CONTENTS
FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 5
1 Scope an d obj ect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 N orm ati ve references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Sam plin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 8
4
5
6
7
8
9
10

M arkin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 8
Testin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 9
Pass criteri a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 9
M aj or visu al defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0
Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 1 0
M od ifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1
Test procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 1 Visu al inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 1 . 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 1 . 2 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 1 . 3 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 2 M axim um power determ ination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 2. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 2. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 2. 3 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
1 0. 3 I nsu lation test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
1 0. 3. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
1 0. 3. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
1 0. 3. 3 Test con d iti on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
1 0. 3. 4 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
1 0. 3. 5 Test req u irem ents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
1 0. 4 M easurem ent of tem perature coeffici ents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
1 0. 4. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
1 0. 4. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
1 0. 4. 3 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
1 0. 5 Measurem ent of n om in al operati n g cell tem perature (N OCT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8
1 0. 5. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8
1 0. 5. 2 I n trod ucti on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8
1 0. 5. 3 Princi pl e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8
1 0. 5. 4 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8

1 0. 5. 5 Test m od u le m ou nting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9
1 0. 5. 6 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9
1 0. 6 Perform ance at STC an d N OCT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1 0. 6. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1 0. 6. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1 0. 6. 3 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1 0. 7 Perform ance at low irrad i ance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1 0. 7. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1 0. 7. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1 0. 7. 3 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1 0. 8 Outd oor exposure test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23


BS EN 61 646:2008
61 646

 I EC: 2008

–3–

1 0. 8. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 8. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 8. 3 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 8. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 8. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 9 H ot-spot en d urance test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 9. 1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 9. 2 H ot-spot effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1 0. 9. 3 Cl assificati on of cel l i n tercon n ecti on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1 0. 9. 4 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

1 0. 9. 5 Proced ure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1 0. 9. 6 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
1 0. 9. 7 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
1 0. 1 0 U V precond i tion i ng test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 0. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 0. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 0. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 0. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 0. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 1 Therm al cycl i n g test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 1 . 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1 0. 1 1 . 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1 0. 1 1 . 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1 0. 1 1 . 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1 0. 1 1 . 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1 0. 1 2 H um id ity-freeze test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1 0. 1 2. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1 0. 1 2. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1 0. 1 2. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 2. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 2. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 3 Dam p heat test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 3. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 3. 2 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 3. 3 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1 0. 1 3. 4 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

1 0. 1 4 Robustness of term in ati ons test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1 0. 1 4. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1 0. 1 4. 2 Types of term in ati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1 0. 1 4. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1 0. 1 4. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 4. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 5 Wet leakag e current test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 5. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 5. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 5. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 5. 4 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 0. 1 6 Mech an ical l oad test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 6. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33


BS EN 61 646:2008
–4–

61 646

 I EC: 2008

1 0. 1 6. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 6. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 6. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 6. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 7 H ail test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

1 0. 1 7. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 7. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1 0. 1 7. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
1 0. 1 7. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1 0. 1 7. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1 0. 1 8 Bypass d iode th erm al test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1 0. 1 8. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1 0. 1 8. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
1 0. 1 8. 3 Proced ure 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
1 0. 1 8. 4 Proced ure 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
1 0. 1 8. 5 Fi nal Measurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
1 0. 1 8. 6 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1 0. 1 9 Light-soakin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1 0. 1 9. 1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1 0. 1 9. 2 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1 0. 1 9. 3 Proced ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1 0. 1 9. 4 Fi nal m easurem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
1 0. 1 9. 5 Req uirem en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Bibli ograph y. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 40
Fi gu re 1 – Qu al ification test seq uence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2
Figu re 2 – N OCT correction factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figu re 3 – H ot-spot effect i n a th i n-fi lm m odu le wi th serial l y con nected cells. Worst
case shad in g con d iti on is sh adi n g of 4 cells at the sam e tim e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figu re 4 – Th erm al cycl in g test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figu re 5 – H um i di ty-freeze cycl e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figu re 6 – H ai l test eq ui pm ent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figu re 7 – I m pact l ocati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figu re 8 – Bypass Di ode Therm al Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Tabl e 1 – Summ ary of test l evels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3
Tabl e 2 – I ce bal l m asses an d test velocities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Tabl e 3 – I m pact locati on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36


BS EN 61 646:2008
61 646

 I EC: 2008

–5–

I NTERNATI ON AL ELECTROTECH NI CAL COMMI SSI ON
___________

THIN-FILM TERRESTRIAL PHOTOVOLTAIC (PV) MODULES –
DESIGN QU ALIFICATION AND TYPE APPROVAL
FOREWORD
1 ) The I nternati on al El ectrotechn i cal Com m i ssi on (I EC) i s a worl d wi d e organi zati on for stand ardi zati on com pri si n g
al l n ati on al el ectrotechn i cal com m i ttees (I EC N ati on al Com m i ttees). Th e obj ect of I EC i s to prom ote
i n ternati on al co-operati on on al l q u esti on s con cern i n g stand ardi zati on in the el ectri cal and el ectron i c fi el d s. To
thi s en d an d i n ad di ti on to oth er acti vi ti es, I EC pu bl i sh es I ntern ati on al Stan dards, Tech n i cal Speci fi cati ons,
Tech n i cal Reports, Pu bl i cl y Avai l abl e Speci fi cati ons (PAS) an d Gu i des (h ereafter referred to as “I EC
Publ i cati on (s)”). Th ei r preparati on i s en trusted to tech n i cal com m i ttees; an y I EC N ati onal Com m i ttee i n terested
i n th e subj ect d eal t with m ay parti ci pate i n th is preparatory work. I ntern ati on al , governm ental an d n on govern m en tal organ i zati on s l iai si ng wi th th e I EC al so partici pate i n thi s preparati on. I EC col l aborates closel y
wi th the I ntern ati onal Organ i zati on for Stand ardi zati on (I SO) i n accordance wi th con d i ti ons determ i ned by
agreem en t between th e two organ i zati ons.
2) The form al d eci si on s or ag reem ents of I EC on tech ni cal m atters express, as n earl y as possi bl e, an i n tern ati onal
con sen su s of opi ni on on th e rel evan t su bj ects si n ce each tech ni cal com m i ttee h as representati on from al l

i nterested I EC N ati on al Com m ittees.
3) I EC Pu bl i cati ons have the form of recom m en dati ons for i ntern ati onal use an d are accepted by I EC N ati on al
Com m i ttees i n th at sense. Whi l e al l reason abl e efforts are m ad e to en su re th at the tech n i cal content of I EC
Pu bl i cati ons i s accu rate, I EC can n ot be h el d respon si bl e for th e way i n wh i ch th ey are used or for an y
m i si n terpretati on by an y en d u ser.
4) I n ord er to prom ote i n tern ati on al u ni form i ty, I EC N ati on al Com m i ttees u nd ertake to appl y I EC Pu bl i cati on s
tran sparen tl y to th e m axi m u m extent possi bl e i n th ei r n ati onal an d regi on al pu bl i cati on s. An y d i vergen ce
between an y I EC Publ i cati on an d the correspon di ng n ati on al or regi on al pu bl i cati on shal l be cl earl y i n di cated i n
the l atter.
5) I EC provi d es no m arki n g procedu re to i nd i cate i ts approval an d can not be rend ered responsi bl e for an y
equ i pm ent decl ared to be i n con form i ty wi th an I EC Pu bl i cati on.
6) Al l users sh ou l d en su re that th ey h ave the l atest edi ti on of th i s pu bl i cati on .
7) N o l i abi l i ty sh al l attach to I EC or i ts d irectors, em pl oyees, servants or ag ents i ncl u d i ng i n d i vi du al experts and
m em bers of i ts tech ni cal com m i ttees an d I EC N ati on al Com m i ttees for an y person al i n j u ry, property d am age or
oth er d am age of an y n ature whatsoever, wheth er d i rect or i n di rect, or for costs (i ncl ud i n g l eg al fees) a n d
expen ses ari si ng ou t of th e pu bl i cati on , use of, or rel i an ce u pon , th i s I EC Publ i cati on or an y other I E C
Publ i cati on s.
8) Attenti on i s d rawn to th e N orm ati ve referen ces ci ted i n thi s publ i cati on. U se of the referen ced pu bl i cati ons i s
i n di spen sabl e for th e correct appl i cati on of th i s pu bl i cati on .
9) Atten ti on i s d rawn to th e possi bi l i ty that som e of th e el em en ts of th i s I EC Publ i cati on m ay be th e su bj ect of
patent ri g hts. I EC shal l not be hel d respon si bl e for i den ti fyi ng an y or al l su ch paten t ri ghts.

I n tern ati on al Stan dard I EC 61 646 h as been prepared by I EC tech n ical comm ittee 82: Sol ar
ph otovoltaic energ y system s.
This secon d ed iti on can cels an d repl aces the fi rst ed iti on pu blish ed i n 1 996. Th is ed i tion
constitutes a techn ical revision .
This ed i ti on inclu des the foll owing si gn ifican t techn ical chan ges wi th respect to the previous
ed i tion:
The m aj or ch ange is i n the pass/fail criteria. I t n o l on ger rel ies on m eeti ng a pl us/m in us
criteri on before an d after each test, but rather on m eeti n g th e rated power after al l of th e tests

have been com pl eted an d th e m od u les h ave been l ight-soaked . Th is was d on e to el im in ate
th e tech n olog y-specific precon d iti on i n g n ecessary to accuratel y m easure the chan ges caused
by th e test. (Som e m od u les l ose power i n l igh t wh i l e others lose power d urin g d ark h eat. )
Since al l m odu l es m ust work after exposure to l igh t, this seem ed l iked a good approach an d
wi l l stream l i ne th e test proced ure, h opefu l l y red ucing th e testin g cost.

•
•

U pd ated N orm ative references.
Add ed a d efi n iti on of “m i n im um valu e of m axim um output power”.


BS EN 61 646:2008
–6–

61 646  I EC: 2008

•

Mod ifi ed th e word i n g i n Maj or visual d efects to al l ow som e ben d in g an d m isal i g nm ent
wi thout fai lu re.

•

Add ed requ irem ents to th e report from I SO/I EC 1 7025.

•

Rem oved th e “Twist Test” as was don e from I EC 61 21 5, since n o on e h as ever fai led th is

test.

•

Mad e th e pass/fai l criteria for insul ati on resistance an d wet l eakage current d epend ent on
th e m od u le area.

•

Add ed th e tem perature coeffici en t of power ( δ ) to th e requ ired m easurem ents.

•

Mod ifi ed tem perature coeffici ent secti on to al low for m easurem ents un d er natural sun l igh t
or a solar sim ulator.

•

Del eted reference pl ate m ethod from N OCT.

•

Add ed apparatus secti on s to th ose test proced ures th at did n ot h ave apparatus secti ons in
ed ition 1 .

•

Rewrote th e h ot-spot test.

•

El im in ated ed g e d ip m eth od from wet leakage curren t test.

•

Ch ang ed m ech anical l oad test to 3 cycl es to be consisten t wi th oth er stan dards.

•

Add ed bypass d i ode th erm al test.

The text of th is stan d ard is based on the fol lowi n g docum en ts:
FDI S

Report on voti n g

82/51 2/FDI S

82/528/RVD

Fu l l inform ation on th e voti ng for th e approval of th is stan dard can be fou nd in th e report on
voti ng in d icated in th e above table.
This publ icati on has been drafted i n accordance with th e I SO/I EC Directi ves, Part 2.
The comm ittee has decided that the con ten ts of th is pu bl icati on will rem ai n unch an g ed un ti l
th e m ai ntenance resu lt date i n d icated on th e I EC web si te u n der "h ttp: //webstore. i ec. ch " in
th e d ata rel ated to the specific publ icati on . At th is date, the pu bl ication wi l l be
•
•
•
•

reconfi rm ed,
wi thdrawn ,
repl aced by a revised ed i ti on, or
am end ed.


BS EN 61 646:2008
61 646

 I EC: 2008

–7–

THIN-FILM TERRESTRIAL PHOTOVOLTAIC (PV) MODULES –
DESIGN QU ALIFICATION AND TYPE APPROVAL

1

Scope and object

This I ntern ati on al Stand ard l ays down req u irem en ts for th e d esi g n q u al ificati on an d type
approval of terrestri al , th i n-fi lm ph otovol taic m od u l es su i table for lon g-term operati on i n
gen eral open-air cl im ates as defi n ed i n I EC 60721 -2-1 . This stan d ard is i ntend ed to appl y to
all terrestri al flat pl ate m od u l e m aterials n ot covered by I EC 61 21 5.
The test sequ ence is derived from I EC 61 21 5 for the desi gn qu al ificati on and type approval of
terrestrial crystall i ne si l icon PV m odu l es. H owever, it n o lon ger rel i es on m eetin g a plus/m in us
criteri on before and after each test, but rath er on m eetin g a specified percen tage of the rated
m inim um power after all of th e tests h ave been com pleted an d th e m odu l es h ave been li gh tsoaked. Th is el im in ates th e tech nol og y-specific precon di tion ing n ecessary to accuratel y
m easure th e ch an ges caused by th e test.

This stan dard d oes n ot appl y to m od u l es used wi th concentrators.
The obj ect of th is test seq u ence is to d eterm i ne th e el ectrical an d thermal ch aracteristics of
th e m odu le an d to show, as far as possi ble wi th i n reason able constraints of cost and tim e,
th at the m odu le is capable of wi thstan d in g prolonged exposure in clim ates described in th e
scope. The actu al life expectancy of m odu l es so q u alified wi ll d epend on th eir d esig n , their
en vironm ent an d th e con d iti ons u n der wh ich th ey are operated.

2

Normati ve references

The fol l owing referenced docum ents are i n d ispen sabl e for th e appl icati on of this d ocum ent.
For d ated references, on l y the ed i tion ci ted appli es. For u n dated references, th e l atest edi tion
of th e referenced d ocum en t (i nclu d i ng an y am end m ents) appl ies.
I EC 60068-1 :

En viro n m e n ta l te stin g – Pa rt 1 : G e n e ra l a n d gu ida n ce

I EC 60068-2-2 1 :

En viro n m e n ta l

te s tin g

–

Pa rt

2-2 1 :

Te s ts

–

Te s t

U:

R o b us tn e s s

of

te rm in a tio n s a n d in te gra l m o un tin g de vic e s

I EC 60068-2-78: 2001 ,

En viro n m e n ta l

te stin g

–

Pa rt

2- 78:

Te s ts

–

Te s t

Ca b :

Da mp

h e a t,

ste a dy s ta te

I EC 6041 0,

Sa m p lin g p la n s a n d p ro ce dure s fo r in s p e ctio n b y a ttrib ute s

I EC 60721 -2-1 ,

Cla s s ifica tio n

of

e n viro n m e n ta l

co n ditio n s

–

Pa rt

2- 1 :

En viro n m e n ta l

co n ditio n s a p p e a rin g in n a ture – Te m p e ra ture a n d h um idity

I EC 60891 ,

Pro c e dure s

fo r

te m p e ra ture

and

irra dia n ce

co rre c tio n s

to

m e a s ure d

I-V

ch a ra cte ristics o f crysta llin e s ilico n p h o to vo lta ic (PV) de vic e s

I EC 60904-1 : 2006,

Ph o to vo lta ic

de vice s

–

Pa rt

1:

Me a s ure m e n ts

o f p h o to vo lta ic

curre n t-

vo lta ge c h a ra cte ris tics

I EC 60904-2,

Ph o to vo lta ic de vic e s – Pa rt 2: Re q uire m e n ts fo r re fe re n ce s o la r de vic e s


BS EN 61 646:2008
–8–
I EC 60904-3,

Ph o to vo lta ic

de vic e s

–

Pa rt

3:

 I EC: 2008

61 646
Me a s ure m e n t

p rin cip le s

fo r

te rre s tria l

p h o to vo lta ic (PV) s o la r de vice s with re fe re n ce s p e ctra l irra dia n c e da ta

I EC 60904-7,

Ph o to vo lta ic

de vic e s

–

Pa rt

7:

Co m p u ta tio n

of

s p e ctra l

m is m a tc h

e rro r

in tro duce d in th e te s tin g o f a p h o to vo lta ic de vice

I EC 60904-9,

Ph o to vo lta ic de vic e s – Pa rt 9 : S o la r s im u la to r p e rfo rm a n c e re qu ire m e n ts

I EC 60904-1 0,
I EC 61 2 1 5,

Ph o to vo lta ic de vice s – Pa rt 1 0: Me th o ds o f lin e a rity m e a s ure m e n ts

Crys ta llin e

silico n

te rre stria l p h o to vo lta ic

(PV)

m o dule s

–

D e sign

q ua lifica tio n

a n d typ e a p p ro va l

I SO/I E C 1 702 5,

G e n e ra l

re qu ire m e n ts

fo r

th e

co m p e te n c e

of

te s tin g

and

ca lib ra tio n

la b o ra to rie s .

3 Sampling
Eig h t m odu l es for qu alifi cati on testin g (plus spares as d esired) sh al l be taken at rand om from
a production batch or batch es, in accordance with th e procedure given in I EC 6041 0. The
m odu les shal l h ave been m anufactured from specified m aterials and com pon ents in
accord ance wi th th e relevan t drawi n gs an d process sh eets an d shal l h ave been su bj ected to
th e m anufacturer's n orm al i nspecti on, qu ality con trol an d production acceptance procedu res.
The m odu l es sh al l be com pl ete in every d etai l an d sh al l be accom pan i ed by th e
m anufacturer's h an d l in g , m oun tin g an d con n ection instructions, incl ud ing the m axim um
perm issi bl e system voltage.
I f the bypass di odes are not accessible i n the stan d ard m od u les, a special sam ple can be
prepared for th e bypass d iod e therm al test (see 1 0. 1 8). Th e bypass d i od e shou l d be m oun ted
ph ysical l y as it wou ld be i n a stan d ard m odu le, with a th erm al sensor placed on th e d i ode as
req u ired in 1 0. 1 8. 2. Th is sam pl e d oes n ot have to go throu gh th e other tests i n the seq u ence.
When th e m odu l es to be tested are prototypes of a n ew d esign an d not from prod uction, th is
fact sh al l be n oted i n th e test report (see Clause 8).

4 Marking
Each m od ul e sh al l carry the fol lowi n g cl ear and in del i ble m arkin gs:

•
•
•
•
•
•

nam e, m on ogram or sym bol of m an ufacturer;
type or m odel n um ber;
serial num ber;

pol arity of term in als or l eads (col our cod in g is perm issible);
m axim um system voltage for wh ich the m od ul e is su itabl e;
nom i nal an d m in im um valu es of m axim um ou tput power at STC, as specified by the
m anufacturer for th e product type.

The m inim um valu e of maxim um output power refers to th e lowest stabi l i zed power th at th e
m anufacturer specifi es for th e prod uct type (for exam ple after an y light i nd uced d egrad ati on
or recovery).
N OTE I f th e m od ul es to be tested are prototypes of a n ew d esi gn an d n ot from prod ucti on , the resu l ts of thi s test
sequ ence m ay be used to establ i sh the m od ul e m i n i m um power rati n g.


BS EN 61 646:2008
61 646

 I EC: 2008

–9–

The d ate an d pl ace of man ufacture sh all be m arked on th e m od u le or be traceabl e from th e
serial n um ber.

5

Testing

The m odu l es sh al l be d ivi ded in to grou ps an d su bj ected to th e q u al ificati on test sequ ences i n
Figu re 1 , carri ed out in the order l aid d own. Each box refers to th e correspon d in g subcl ause
in th is stan dard. Test proced ures an d severities, incl ud i n g in itial and fi nal m easurem ents
wh ere necessary, are detai led i n Clause 1 0. H owever, wi th regard to the tests of 1 0. 2, 1 0. 4,

1 0. 6 an d 1 0. 7, it shou ld be noted that the proced ures lai d d own i n I EC 60891 for tem peratu re
an d irradiance correction s to m easured I -V ch aracteristics appl y on l y to l i near m od u l es. U se
I EC 60904-1 0 to assess l in earity. I f th e m odu le is n on-li n ear, th ese tests shal l be carried out
within ±5 % of th e specifi ed irrad iance an d within ±2 °C of the specifi ed tem perature.
N OTE 1 Where the fi n al m easu rem ents for on e test serve as the i ni ti al m easurem en ts for th e next test i n th e
seq uen ce, they n eed n ot be repeated . I n these cases, the i n i ti al m easurem ents are om i tted from the test.
For di agnosti c pu rposes, i nterm ed i ate m easurem en ts of m axi m um power (1 0. 2) m ay be u nd ertaken before an d
after i n di vid u al tests.
N OTE 2

Th e control m od ul e sh ou l d be stored i n accordance wi th the m an ufactu rer’ s recom m end ati on .

An y si ng l e test, executed i nd epen den tl y of a test sequ ence, sh al l be preceed ed by th e i n iti al
tests of 1 0. 1 , 1 0. 2 and 1 0. 3.
I n carryi n g out th e tests, th e tester shal l strictl y observe th e m an ufacturer's han dl in g,
m ounti n g an d con n ecti on i nstructi ons. Tests gi ven i n 1 0. 4, 1 0. 5, 1 0. 6 an d 1 0. 7 m ay be
om itted if fu ture I EC 61 853 has been or is sch edu l ed to be ru n on th is m od u le type.
Thin fi lm techn ologi es can have d ifferent stabi l i zati on ch aracteristics. I t is i m possi ble to d efi n e
a sing l e stabi l isation proced ure applicabl e to al l th i n fi lm tech n ol og ies. Th is procedure tests
th e m od u l es “as recei ved “ an d attem pts to reach a stabi l ised con d iti on before fin al test.
Test con d iti on s are summ ari zed i n Table 1 .
N OTE 3 Th e test l evel s i n Tabl e 1 are th e m i ni m um l evel s req ui red for qu al i fi cati on . I f th e l aboratory an d th e
m odu l e m anu factu rer ag ree, th e tests m ay be perform ed wi th i ncreased severi ti es.

6

Pass criteria

A m odu l e d esi gn sh all be j ud ged to h ave passed the qu al ificati on tests, and th erefore, to be
I EC type approved, if each test sam pl e m eets al l the fol lowi n g criteria:

a) after the fin al l ig ht soakin g, th e m axim um output power at STC is n ot l ess than 90 % of the
m inim um valu e specified by th e m anufacturer in Cl ause 4;
N OTE The pass/fai l cri teri a m ust consi der th e l aboratory u n certai nty of th e m easurem ent. As an exam pl e, i f
the l aboratory exten d ed un certai n ty, 2 si gm a of th e STC m easu rem en t, i s ±5 % , th en a m axi m um power
m easu rem ent greater th an 85, 5 % of th e m i ni m um speci fi ed val ue woul d be th e pass cri teri a.

b) no sam pl e has exh i bited an y open-circu i t du ri n g th e tests;
c) th ere is n o visu al evid ence of a m ajor d efect, as d efi ned i n Cl ause 7;
d) th e insul ation test req uirem ents are m et after the tests;
e) th e wet leakage current test requ irem en ts are m et at the begin n i ng an d the en d of each
seq u ence an d after th e d am p h eat test;
f) specific req u irem ents of the in d i vid u al tests are m et.
I f two or m ore m od ules do n ot m eet these test criteri a, the d esi gn sh al l be deem ed n ot to
have m et the qu al ificati on requ irem ents. Sh ould one m od u l e fai l an y test, an oth er two
m odu les m eeti n g th e req u irem en ts of Clause 3 sh all be subj ected to th e whol e of th e rel evan t


BS EN 61 646:2008
– 10 –

61 646

 I EC: 2008

test seq u ence from th e beg i nn i ng. I f on e or both of th ese m od u les also fail , th e d esign sh al l
be d eem ed n ot to h ave m et th e qu al ificati on req u irem ents. I f, h owever, both m od u l es pass th e
test sequ ence, th e d esign sh al l be j u dg ed to have m et th e q ual ificati on req u irem en ts.

7 Major visual defects
For th e purposes of design q ualification an d type approval , th e fol lowi n g are consid ered to be

m aj or visu al defects:
a) broken, cracked, or torn external surfaces, i nclu d i ng su perstrates, su bstrates, fram es an d
j unction boxes;
b) ben t or m isal i gn ed extern al surfaces, incl ud i n g superstrates, su bstrates, fram es an d
junction boxes to th e exten t th at th e install ation and /or operation of th e m od u le wou l d be
im paired ;
c) voids in , or visi bl e corrosion of an y of th e th in film layers of the acti ve circui try of th e
m odu le, exten di n g over m ore th an 1 0 % of an y cell ;
d) bu bbles or d elam i nation s form ing a conti nu ous path between an y part of th e el ectrical
circuit and th e edge of th e m od u l e;
e) loss of m ech anical integrity, to th e extent that th e i nstal lation and /or operati on of th e
m odu le wou ld be im paired;
f) Mod u le m arkin gs (l abel) i s n o l onger attached or the inform ati on is u nread abl e.

8 Report
Fol lowin g type approval, a certified report of th e qu al ification tests, with m easured
perform ance ch aracteristics an d d etails of an y fai l ures and re-tests, sh al l be prepared by th e
test ag ency i n accordance with I SO/I EC 1 7025. Each certificate or test report sh all i ncl u d e at
least th e followi n g i nform ati on .
a)
b)
c)
d)

A titl e.
N am e an d ad dress of the test l aboratory an d l ocati on wh ere th e tests were carried out.
U n i qu e i d en tificati on of the certificati on or report an d of each page.
N am e an d ad dress of cl i en t, wh ere appropri ate.

e)

f)
g)
h)

Descri ption an d i d en tificati on of th e i tem tested .
Ch aracteri zation an d con d iti on of the test item .
Date of receipt of test i tem and d ate(s) of test, wh ere appropri ate.
I d entificati on of test m eth od used.

i)
j)

Reference to sam plin g proced ure, wh ere rel evan t.
An y d eviations from , ad d iti ons to or excl usi ons from the test m ethod , an d an y oth er
inform ation relevan t to a specific tests, such as en vironm en tal con d itions.
k) Measurem ents, exam i nati ons an d derived resu l ts su pported by tabl es, graphs, sketches
an d ph otographs as appropri ate incl u di n g tem perature coefficients of sh ort circu it current,
open circuit voltage and peak power, N OCT, power at N OCT, STC and low irrad i ance, th e
m axim um shad ed cell tem perature observed during th e hot-spot test, spectrum of th e lam p
used for th e U V prescreen i n g test, m in im um power observed after l i ght soaki n g an d an y
fai l ures observed . I f th e m axim um power loss observed after each of th e tests h as been
m easured it sh oul d also be reported.
l) A statem ent of the estim ated uncertai nty of the test resu l ts (wh ere rel evan t).
m ) A si gnature an d ti tl e, or eq u ival ent id entification of th e person(s) accepti ng responsibil ity
for th e con ten t of th e certificate or report, an d th e date of issu e.
n) Where rel evan t, a statem en t to th e effect th at the resu l ts relate onl y to the item s tested.


BS EN 61 646:2008
61 646

 I EC: 2008

– 11 –

o) A statem ent th at th e certi ficate or report sh all not be reprod uced except in ful l, with out th e
wri tten approval of th e l aboratory.
A copy of th is report sh al l be kept by th e l aboratory an d m an ufacturer for reference purposes.

9 Modifications
An y ch ange in th e d esign, m aterials, com pon ents or processi ng of the m odu l e m ay req uire a
repeti tion of som e or al l of th e qu al ificati on tests to m ai n tai n type approval .


BS EN 61 646:2008
– 12 –

61 646

 I EC: 2008

8 Modules
1 0.1
Visual inspection
1 0.2
Max power determination
1 0.3
Insulation test
1 0.1 5
Wet leakage current test

1 Module

1 Module

2 Modules

2 Modules

2 Modules

1 0.8
Outdoor exposure test
60 kWh/m 2

1 0.1 0
UV precondition test
1 5 kWh/m 2

1 0.1 1
Thermal cycling test
200 cycles
–40 °C to 85 °C

1 0.4
Measurement of
temperature coefficients
(see Note 1 )

1 0.1 1

Thermal cycling test
50 cycles
–40 °C to 85 °C

1 0.1 3
Damp heat test
1 000 h
85 °C
85 % RH

1 0.5
NOCT
(see Note 2)
C
o
n
t
r
o
l

1 0.6
Performance at
STC and NOCT (see Note 1 )
1 0.7
Performance at
low irradiance (see Note 1 )
1 0.1 8
Bypass diode
thermal test

(see Note 3)

1 0.1 2
Humidity freeze test
1 0 cycles
–40 °C to 85 °C
85 % RH

1 Module

1 Module

1 0.1 4
Robustness of
terminations test

1 Module

1 Module

1 0.1 6
Mechanical
load test

1 0.1 7
Hail test

1 0.9
Hot-spot
endurance test

1 0.1 5
Wet leakage
current test

1 0.1 9
Light soaking

1 0.1 5
Wet leakage
current test

N OTE 1

May be om i tted i f fu ture I EC 61 853 has been perform ed.

IEC 587/08

N OTE 2 I n th e case of m od ul es n ot desi gn ed for open-rack m oun ti n g, th e N OCT m ay be repl aced by th e
eq ui l i bri um m ean sol ar cel l j un cti on tem peratu re i n th e stan d ard referen ce en vi ronm ent, wi th the m odul e m ou nted
as recom m end ed by the m an ufacturer.
N OTE 3 I f the bypass di od es are not accessi bl e i n th e stan dard m od ul es, a speci al sam pl e can be prepared for
the bypass d i ode th erm al test (1 0. 1 8). Th e bypass d i od e sh ou l d be m oun ted ph ysi cal l y as i t woul d be i n a stand ard
m odu l e, wi th a th erm al sen sor pl aced on the di od e as requ i red i n 1 0. 1 8. 2. Th i s sam pl e d oes n ot h ave to go th roug h
the oth er tests i n th e seq u en ce.
N OTE 4 For di agnosti c pu rposes i n term edi ate m easurem ents of m axi m um power (1 0. 2) m ay be u nd ertaken
before and after i nd i vi d u al tests. I f the con trol m odu l e i s used for these m easu rem en ts m ake su re i t h as been precond i ti oned per the m an ufacturers recom m en dati on .

Figu re 1 – Qu al ifi cation test sequ en ce

BS EN 61 646:2008
61 646

 I EC: 2008

– 13 –

Table 1 – Su mm ary of test levels
Test

Ti tl e

Test conditi on s

1 0. 1

Vi su al i nspecti on

See detai l ed i nspecti on l i st i n 1 0. 1 . 2

1 0. 2

M axi m um Power Determ i nati on

See I EC 60904-1

1 0. 3

I n sul ati on test

Di el ectri c wi thstan d at 1 000 V d . c. + twi ce th e m axi m u m
system vol tage for 1 m i n. For m od ul es wi th an area l ess than
0, 1 m 2 th e i nsul ati on resi stance shal l n ot be l ess than 400 M Ω .
For m odul es wi th an area l arger than 0, 1 m 2 , the m easu red
i nsul ati on resi stance ti m es the area of the m od u l e sh al l n ot be
l ess th an 40 M Ω⋅ m 2 . Measu red at 500 V or m axi m u m system
vol tage, whi ch ever is g reater.

1 0. 4

M easu rem en t of tem peratu re coeffi ci en ts

1 0. 5

Measurem ent of N OCT

See detai l i n 1 0. 4
See I EC 60904-1 0 for gui dan ce.
Total sol ar i rrad i an ce:

800 W ⋅ m –2

Am bi ent tem perature:

20 ° C

Wi nd speed:

1 m ⋅ s –1

Cel l tem peratu re: 25 ° C and N OCT
1 0. 6

Perform ance at STC an d N OCT

I rradi an ce: 1 000 and 800 W ⋅ m –2 wi th I EC 60904-3 reference
sol ar spectral i rradi an ce d i stri bution
Cel l tem peratu re: 25 ° C

1 0. 7

Perform an ce at l ow i rradi an ce

I rradi an ce: 200 W ⋅ m –2 wi th I EC 60904-3 referen ce
sol ar spectral i rradi an ce d i stri buti on
60 kWh ⋅ m –2 total sol ar i rrad i ati on u n der resi sti ve l oad

1 0. 8

Ou td oor exposu re test

1 0. 9

H ot-spot en du rance test

1 0. 1 0

U V Precon d i ti on i n g

1 5 kWh ⋅ m –2 total U V i rrad i ati on i n the wavel en gth ran g e from

280 n m to 385 n m wi th 5 kWh ⋅ m –2 U V i rradi ati on i n th e
wavel en gth ran g e from 280 to 320 nm u nd er resi sti ve l oad .

1 0. 1 1

Therm al cycl i n g test

50 and 200 cycl es from – 40 ° C to +85 ° C

1 0. 1 2

H um i di ty freeze test

1 0 cycl es from +85 °C, 85 % RH to –40 ° C

1 0. 1 3

Dam p heat test

1 000 h at +85 ° C, 85 % RH

1 0. 1 4

Robu stness of term i nati on s test

As i n I EC 60068-2-21

One h ou r exposu re to 1 000 W ⋅ m –2 i rrad i ance
i n worst-case h ot-spot cond i ti on

See d etai l i n 1 0. 1 5
Test perform ed at test vol tag e 500 V or m axi m um system s
vol tage, whi ch ever i s h i gh er for 1 m i n . For m od ul es wi th an
area l ess th an 0, 1 m 2 the i nsu l ati on resi stance sh al l n ot be
l ess than 400 M Ω . For m od ul es wi th an area l arg er th an 0, 1 m 2
th e m easured i n sul ati on resi stance ti m es the area of th e
m od ul e shal l n ot be l ess th an 40 M Ω⋅ m 2 .

1 0. 1 5

Wet l eakage cu rrent test

1 0. 1 6

Mech ani cal l oad test

Three cycl es of 2 400 Pa un i form l oad, appl i ed for 1 h to front
and back su rfaces i n tu rn . Opti on al sn ow l oad of 5 400 Pa
d uri n g l ast fron t cycl e.

1 0. 1 7

H ai l test

25 m m di am eter i ce bal l at 23, 0 m ⋅ s –1 , d i rected at 1 1 i m pact
l ocati ons

1 0. 1 8

Bypass di od e th erm al test

1 0. 1 9

Li ght-soaki n g

On e h ou r at

Isc

an d 75 ° C

One h ou r at 1 , 25 tim es

Isc

and 75 ° C

Li ght exposu re of 800 W ⋅ m –2 to 1 000 W ⋅ m –2 u nd er resi sti ve
l oad un ti l P m a x i s stabl e wi th i n 2 % .


BS EN 61 646:2008
– 14 –

61 646

 I EC: 2008

1 0 Test procedures
1 0. 1

1 0. 1 . 1

Vi su al i nspection
Pu rpose

To d etect an y vi su al d efects i n th e m od u l e.

1 0. 1 . 2

Procedu re

Carefu l l y i nspect each m odu le un d er an i l lum i nation of n ot l ess th an 1 000 l ux for th e
fol l owing con d iti ons:
–
–
–
–
–
–

cracked , ben t, m isal ig n ed or torn extern al surfaces;
fau lty i n tercon nections or j oi nts;
voids in , and visible corrosion of an y of the th i n fil m layers of th e acti ve circu it;
visibl e corrosion of outpu t con n ecti ons, i nterconn ections and busbars;
fai l ure of ad hesi ve bon ds;
bu bbles or d el am in ati on s form ing a conti nu ous path between a cell an d th e ed ge of th e
m odu le;

–
–

–

tacky surfaces of pl astic m aterials;
fau lty term in ati ons, exposed l i ve el ectrical parts;
an y other con d iti ons wh ich m ay affect perform ance.

Make n ote of and /or ph otograph the n ature and posi ti on of an y cracks, bu bbl es or
del am in ation, etc. , wh ich m ay worsen an d ad versel y affect th e m od u le perform ance i n
subsequ ent tests.

1 0. 1 . 3

Requi rements

Visu al con d iti ons other than th e m aj or visual d efects l isted in Clause 7 are acceptabl e for the
purpose of type approval.

1 0. 2 M aximu m power determ ination
1 0. 2. 1

Pu rpose

To determ i ne th e m axim um power of th e m odu l e before an d after th e vari ous en vironm ental
tests. Repeatabil ity of th e test is th e m ost im portant factor.

1 0. 2. 2

Apparatu s

a) A rad i an t source (natural sun li gh t or a solar sim ul ator Cl ass BBA or better in accord ance

wi th I EC 60904-9.
b) A PV reference device i n accord ance wi th I EC 60904-2. I f a Class BBA sim ulator is used,
th e reference d evice sh all be a reference m od u le of th e sam e size wi th th e sam e cel l
tech nolog y (to m atch spectral response) as th e test specim en .
c) A su itabl e m oun t for su pporti n g the test specim en and th e reference d evice i n a plan e
norm al to th e rad iant beam .
d) Apparatus for m easuri ng an I -V curve in accord an ce with I EC 60904-1 .

1 0. 2. 3

Procedu re

Determ i ne th e curren t-voltage ch aracteristic of th e m od u le in accordance with I EC 60904-1 at
a specific set of irrad iance and tem perature con d iti ons (a recomm end ed ran ge is a cell


BS EN 61 646:2008
61 646

 I EC: 2008

– 15 –

tem perature between 25 an d 50 ° C and an irrad i ance between 700 W ⋅ m –2 an d 1 1 00 W ⋅ m –2 )
usin g n atural su nli ght or a class BBA or better sim ul ator conform i ng to the req u irem ents of
I EC 60904-9. I n speci al circum stances when m od u l es are d esign ed for operati on un d er a
d ifferent ran ge of con d i tions, th e current-voltage ch aracteristics can be m easured usin g
tem perature and irrad i ance levels sim il ar to th e expected operati n g con d iti ons. For l in ear
m odu les tem perature an d irrad iance correcti ons can be m ade in accord ance wi th I EC 60891 .
For n on l i near m odu l es the m easu rem en t sh al l be perform ed wi th in ±5 % of th e specifi ed

irrad i ance and wi th in ±2 ° C of th e specifi ed temperature. Every effort shou ld be m ad e to
assure that peak power m easurem ents are m ad e u nd er sim i lar operati ng con d iti ons, that is,
m inim ize the m ag n itu de of th e correction by m akin g al l peak power m easurem ents on a
particu lar m odu l e at approxim atel y the sam e tem perature an d irrad iance.
N OTE

Th e control m odu l e m ay be used as a ch eck every ti m e th e test m odu l es are m easu red .

1 0. 3 Insul ati on test
1 0.3. 1

Pu rpose

To d eterm in e wh eth er or not th e m odu l e is suffici entl y wel l insu lated between cu rrent carryin g
parts and th e fram e or th e outside worl d.

1 0. 3. 2

Apparatu s

a) A d . c. vol tage source, wi th current l im itation , capabl e of appl yi n g 500 V or 1 000 V pl us
twice the m axim um system voltage of th e m odu l e (as m arked on th e m odu le – see Clause
4) accord in g to item c) of 1 0. 3. 4.
b) An i nstrum ent to m easu re th e i nsu lation resistance.

1 0. 3.3

Test conditions

The test sh al l be m ad e on m odu l es at am bient tem perature of th e surroun d i ng atm osph ere

(see I EC 60068-1 ) an d i n a rel ati ve h um id ity n ot exceed i ng 75 %.

1 0. 3. 4

Procedu re

a) Con nect th e shorted ou tput term in als of th e m od u l e to th e posi ti ve term inal of a d. c.
i nsu l ati on tester wi th a curren t l im itati on .
b) Con nect the exposed metal parts of th e m od ul e to th e n eg ati ve term in al of the tester.
I f the m od u le h as n o fram e or if the fram e is a poor electrical con d uctor, wrap a cond uctive
foi l aroun d the ed ges and over th e back of the m odu l e. I f the m od ul e does n ot have a
glass su perstrate, also wrap the foil arou n d th e fron t of th e m od u le. Conn ect the foi l to the
negati ve term i nal of the tester.

c) I n crease th e vol tag e appli ed by th e tester at a rate n ot exceed i n g 500 V ⋅ s –1 to a
m axim um eq u al to 1 000 V pl u s twi ce th e m axi m um system vol tag e (i . e. th e m axi m um
system vol tag e m arked on th e m od u l e by th e m an u factu rer, see Cl au se 4). I f th e
m axim um system vol tag e d oes n ot exceed 50 V, th e appl i ed vol tage sh al l be 500 V.
M ai n tai n th e vol tag e at th i s l evel for 1 m in .

d ) Red u ce th e appl i ed vol tag e to zero an d sh ort-ci rcu i t th e term i n als of th e test eq u i pm en t
to d i sch arg e th e vol tag e bu i l d -u p i n th e m od u l e.
e) Rem ove th e sh ort ci rcu i t.
f) I n crease th e vol tag e appl i ed b y th e test eq u ipm en t at a rate n ot to exceed 500 V ⋅ s –1 to
500 V or th e m axim u m system vol tage for th e m od u l e, wh i ch ever i s greater. M ai n tai n the
vol tag e at th i s l evel for 2 m in . Th en d eterm i n e th e i n su l ation resi stan ce.
g) Red u ce th e appl i ed vol tag e to zero an d sh ort-ci rcu i t th e term i n al s of th e test eq u i pm en t
to d i sch arg e th e vol tag e bu i l d -u p i n th e m od u l e.
h ) Rem ove th e sh ort circu i t an d d i scon n ect th e test eq u i pm en t from th e m od u l e.

BS EN 61 646:2008
– 16 –

1 0. 3.5
–
–
–

61 646  I EC: 2008

Test requ irements

no di el ectric breakdown or surface trackin g d urin g step c);
for m odu l es wi th total area less than 0, 1 m 2 , the i nsul ati on resistance sh all n ot be l ess
th an 400 M Ω ;
for m odu les wi th total area l arg er th an 0, 1 m 2 th e m easured i nsu lation resistance tim es
th e area of the m od u le shal l n ot be less th an 40 M Ω⋅ m 2 .

1 0. 4 M easu rement of temperatu re coeffi cients
1 0. 4. 1

Pu rpose

To determ in e the tem perature coeffici ents of curren t ( α ) an d voltag e ( β ) and peak power ( δ )
from m odule m easurem en ts. Th e coefficients so d eterm in ed are vali d at th e i rrad i ance at
wh ich the m easurem ents were m ade. For l in ear m odu l es, th ey are also val id over an
irrad iance ran ge of ±30 % of th is l evel. Th is proced ure suppl em ents that i n I EC 60891 for
m easurin g th ese coeffici en ts from a represen tative set of si n g le cells. The tem perature
coefficien ts of a th i n-fi lm m odu l e m ay depend u pon th e irrad i ati on and th e th erm al h istory of

th e m odu le. When tem perature coefficien ts are referred to, th e h istory concern in g the
con d iti ons an d the resu l ts of irradi ati on alon g wi th therm al tests sh all be in d icated .

1 0.4.2

Apparatu s

The fol lowi ng apparatus i s req uired to con trol an d m easure th e test con di tions:
a) a rad ian t source (n atural sun l igh t or sol ar sim ul ator, class BBB or better in accord ance
wi th I EC 60904-9) of th e type to be used i n su bsequ ent tests;
b) a PV reference d evice havi ng a known sh ort-circu i t current versus irrad iance ch aracteristic
determ in ed by cali brati ng ag ai nst an absolu te radi om eter in accord ance with I EC 60904-2;
c) an y eq u ipm en t necessary to ch ange the tem perature of the test specim en over th e rang e
of in terest;
d) a sui tabl e m ou nt for supportin g the test specim en an d th e reference d evi ce in th e sam e
plan e norm al to th e rad iant beam ;
e) apparatus for m easurin g an I -V curve in accord an ce with I EC 60904-1 .

1 0.4.3

Procedure

There are two acceptable proced ures for m easurin g th e tem perature coeffici en ts.

1 0.4.3. 1

Procedure in natu ral sunlig ht

a) M easurem ent in n atural sun l i gh t sh all on l y be m ad e wh en:
– th e total irrad i ance is at l east as h igh as th e u pper lim it of the ran g e of in terest;

– th e irrad iance vari ation caused by sh ort-term oscil lations (cl ou ds, h aze, or sm oke) is
l ess th an ± 2 % of th e total irrad i ance as m easured by the reference d evice;
– th e win d speed is l ess th an 2 m ⋅ s –1 .
b) Mou nt th e reference d evice co-planar wi th th e test m od u le so that both are norm al to th e
d irect solar beam with in ± 5 ° . Con n ect to th e n ecessary i nstrum en tation .
N OTE The m easurem en ts descri bed i n the fol l owi n g su bcl auses shoul d be m ad e as exped i ti ou sl y as possi bl e
wi th i n a few h ours on th e sam e d ay to m i nim i ze th e effect of ch an g es i n th e spectral cond i ti on s. I f n ot, spectral
correcti on s m ay be req ui red .

c) I f the test m od ul e an d reference d evice are eq u i pped wi th tem perature con trols, set th e
con trols at the desired l evel.
d) I f tem perature con trols are n ot used , sh ade th e specim en and th e referen ce d evice from
th e su n and win d u nti l its tem perature is u n iform with i n ± 1 ° C of the am bi en t air
tem perature, or al l ow th e test specim en to equ i l i brate to i ts stabi l i zed tem perature, or cool


BS EN 61 646:2008
61 646

 I EC: 2008

– 17 –

th e test specim en to a poin t below the req u ired test tem perature an d th en l et th e m odu le
warm up n atural l y. Th e reference device sh ou l d also stabi l i ze wi th i n ± 1 ° C of its
eq u i l ibri um tem perature before proceed i n g.
e) Record th e curren t-voltage characteristic and tem perature of th e specim en concurrentl y
wi th record in g th e sh ort-circu it current an d temperature of the reference d evice at the
desired tem peratures. I f necessary, m ake th e m easurem en ts im m ed iatel y after rem ovin g
th e sh ad e.

f) The irrad i ance G 0 shal l be calcu l ated in accord ance wi th I EC 60891 from the m easured
curren t ( Isc ) of th e PV reference d evice, and its cal ibrati on value at STC ( Irc ). A correction
shou l d be appl ied to accou n t for th e tem perature of th e reference d evice Tm using the
specified tem perature coeffici ent of the reference device α rc .
Go

= 1000 ×I sc ×[1 −α rc (Tm −25 )]
Irc

Where α rc is the relative tem perature coefficient [ ° C –1 ] at 25 ° C an d 1 000 W ⋅ m –2 .
g) Adj ust the tem perature by m eans of a con trol l er or alternatel y exposin g and shad in g the
test m od u le as req uired to ach ieve an d m aintain the d esired tem perature. Alternatel y, th e
test m od ul e m ay be allowed to warm -u p n atural ly with the d ata record in g procedure of
item d) perform ed period icall y d urin g th e warm -up.
h) Ensure th at th e test m od u le and reference device tem perature are stabil ized and rem ain
constan t with in ± 1 ° C and th at th e irrad iance as m easured by the reference device
rem ains constan t within ± 1 % durin g th e record in g period for each d ata set. Al l d ata m ust
be taken at 1 000 W ⋅ m –2 or be transl ated to that irrad iance l evel using I EC 60891 . The
translation can on l y be perform ed with in the ran ge of irrad iance wh ere th e m odu le is l in ear
as d efined in I EC 60904-1 0.
i) Repeat steps d) throu gh h). M od ul e tem peratures sh al l be such that the ran ge of in terest
is at l east 30 °C an d th at it is span ned in at l east four approxim atel y equ al i ncrem ents.
A m in im um of three m easurem ents sh al l be m ad e at each of the test con d itions.

1 0.4.3.2

Procedure with a solar simulator

a) Determ ine the sh ort-circu it curren t of th e m od u le at the d esired irrad iance at room
tem perature, in accord an ce with I EC 60904-1 .

b) Mou nt th e test m od u l e in the eq u ipm ent used to chan ge th e tem peratu re. Con n ect to the
instrum entation.
c) Set th e irrad iance so th at the test m od u le produces th e sh ort-circu it current d eterm in ed in
item a).
d) H eat or cool th e m odu le to a tem peratu re of in terest. Once the m odu l e h as reach ed the
desired tem perature, m easure Is c , Voc and peak power. Ch ange the m od ul e tem perature in
steps of approxim atel y 5 °C over a range of interest of at least 30 °C and repeat
m easurem ents of Isc , Voc an d peak power.
N OTE 1 Th e com pl ete cu rrent-vol tage ch aracteri sti c m ay be m easu red at each tem peratu re to determ i ne th e
tem peratu re chang e i n vol tage at peak power and cu rren t at peak power.
N OTE 2 Care sh oul d be taken to assu re th at th e test m odu l e i s correctl y pre-cond i ti on ed before each
m easu rem en t.

1 0.4.3.3

Calculation of temperature coefficients

a) Plot th e val ues of Isc , Voc an d Pm ax as functions of tem perature and construct a leastsqu ares-fi t curve through each set of d ata.
b) From the slopes of th e least sq u ares, fit straigh t l ines for cu rrent, voltage an d Pm ax.
Calcu late α , th e tem perature coefficien t of sh ort circu it current, β , the tem perature


BS EN 61 646:2008
– 18 –

61 646  I EC: 2008

coefficien t of open circu it voltage, an d δ , the tem perature coefficient of Pm ax, for th e
m odu le.
N OTE 1

See I EC 60904-1 0 to determ i n e i f th e test m odu l es can be con si d ered to be l i n ear d evi ces.

N OTE 2 Th e tem peratu re coeffi ci ents m easu red i n thi s proced u re are on l y val i d at the i rradi an ce l evel an d
spectrum at wh i ch they were m easured. Rel ati ve tem peratu re coeffi ci en ts expressed as percentag es can be
determ i ned by d i vi d i ng the cal cu l ated α , β , an d δ by th e val ues of current, vol tag e an d peak power at 25 ° C.
N OTE 3 Becau se th e fi ll factor of th e m odu le is a fu n cti on of tem peratu re, i t i s n ot su ffi ci en t to use th e prod uct of

α and β as the tem peratu re coeffi ci ent of peak power.

1 0. 5 M easu rement of nominal operating cell temperatu re (N OCT)
1 0. 5. 1

Pu rpose

To d eterm in e the N OCT of th e m od u le.

1 0. 5. 2

Introdu ction

NOCT is d efined as th e eq u il ibrium m ean sol ar cell j u nction tem perature within an open-rack
m ounted m od u le in th e fol lowin g stan d ard reference en vironm ent (SRE):
–

til t angl e:

at 45° til t from th e h orizontal

–

–

total irrad iance:
am bien t tem perature:

800 W ⋅ m –2
20 °C

–
–

wind speed:
electrical load:

1 m ⋅ s –1
n il (open circu it)

NOCT can be used by th e system designer as a gu id e to th e tem perature at wh ich a m odu l e
wil l operate in the field an d it is th erefore a useful param eter wh en com parin g th e perform ance of d ifferent m odu l e designs. H owever, the actu al operatin g tem perature at an y particu lar
tim e is affected by th e m ou n tin g structure, irradiance, win d speed , am bien t tem perature, sky
tem perature and reflections an d em issions from the groun d and n earby obj ects. For accurate
perform ance pred ictions, these factors sh all be taken in to accou nt.
I n the case of m odu l es not designed for open -rack m ounting, th e m eth od m ay be used to
determ in e th e eq u ilibriu m m ean solar cel l j unction tem perature in the SRE, with th e m od u le
m ounted as recomm end ed by the m anufacturer.

1 0.5.3

Principl e

This m eth od is based on gath erin g actual m easu red cell tem perature d ata u nd er a ran ge of
en vironm ental con ditions incl ud in g the SRE. The data are presented in a way th at al lows
accurate an d repeatabl e interpol ation of the N OCT.
The tem perature of th e solar cel l j unction ( TJ ) is prim aril y a fu nction of th e am bien t
tem perature ( Tamb), th e average win d speed ( V) an d th e total sol ar irradiance ( G) inciden t on
th e active surface of th e m od u l e. The tem perature difference ( TJ – Tamb) is l argel y
ind epen dent of th e am bient tem perature an d is essen ti al l y l in earl y proportional to th e
irrad iance at levels above 400 W ⋅ m –2 . The procedure cal ls for plottin g ( TJ – Tamb) against G
for a period when win d cond itions are favourabl e. A prel im in ary N OCT value is then
determ in ed by add ing 20 ° C to th e value of ( TJ – Tamb) interpolated at the SRE irrad iance of
800 W ⋅ m –2 . Finall y, a correction factor, d epend en t on th e average tem perature an d win d
speed d uring th e test period, is ad d ed to th e prelim inary N OCT to correct it to 20 ° C an d
1 m ⋅ s –1 .

1 0. 5. 4

Apparatu s

The fol l owing apparatus is req uired:


BS EN 61 646:2008
61 646

 I EC: 2008

– 19 –

a) An open rack to su pport th e test m odu le(s) and pyran om eter in the specified m ann er (see
1 0. 5. 2). The rack sh al l be designed to m in im ize h eat cond uction from the m odu les an d to

interfere as l ittl e as possibl e with th e free rad iation of heat from their fron t an d back
surfaces.
N OTE I n th e case of m od ul es not d esi g n ed for open -rack m oun ti ng, th e test m od ul e(s) sh ou l d be m oun ted as
recom m end ed by the m an ufacturer.

b) A pyranom eter, m ou nted in th e pl an e of th e m odu l e(s) and with in 0, 3 m of the test array.

c) I nstrum ents to m easu re wind speed down to 0, 25 m ⋅ s –1 with an accuracy of ±1 0 % or
0, 2 m ⋅ s –1 wh ich ever is greater an d win d d irection with an accuracy of ±1 0 ° , instal led
approxim atel y 0, 7 m above th e top of the m od ul e(s) an d 1 , 2 m to the east or west.
d) An am bient tem perature sensor, with a tim e constant approach ing th at of th e m odu l e(s),
install ed in a sh ad ed encl osure with good ven til ati on near the win d sensors.
e) Cel l tem perature sensors, attach ed by sold er or therm al l y cond uctive adh esive to th e
backs of two solar cel ls near th e m id dl e of each test m od ule, or oth er eq uipm en t
necessary for I EC-approved m easurem ent of cel l tem perature.
f) A d ata acqu isition system with tem perature m easurem ent accuracy of ±1 ° C to record th e
fol l owing param eters with in an in terval of no m ore th an 5 s:
– irrad iance;
– am bient tem perature;
– cell tem perature;
– win d speed;
– win d d irecti on .

1 0. 5.5

Test modu le mounting

Tilt angl e : the test m od ul e(s) sh al l be position ed so that it is til ted at 45 °
with th e fron t side pointed toward th e eq u ator.

± 5°

to the horizontal

H eigh t : the bottom ed ge of th e test m od u l e(s) shal l be 0, 6 m or m ore above the l ocal
horizon tal plan e or groun d l evel .
Configuration : to sim u late th e therm al bound ary con d itions of m odu l es in stall ed in an array,
th e test m odu le(s) sh all be m ou n ted with in a pl an ar surface that exten ds at least 0, 6 m
beyon d th e m odu l e(s) in al l d irections. For m odu les design ed for free-stan d ing, open-back
install ations, black al um in ium plates or oth er m od u les of the sam e d esign shal l be used to fil l
ou t the rem ain in g open area of the pl an ar surface.
Surrou n ding area: th ere shall be n o obstructions to prevent fu l l irrad iance of th e test
m odu le(s) d uring the period from 4 h before local solar n oon to 4 h after local sol ar n oon. The
grou nd surround ing the m odu le(s) shal l not have an abn orm all y high sol ar refl ectance and
shal l be fl at an d l evel or sl oping away from th e test fixture in al l d irections. Grass, oth er types
of vegetation, black asph alt or d irt are acceptabl e for th e local surrou nd ing area.

1 0. 5. 6

Procedu re

a) Set u p th e apparatus with the test m od u le(s), as described in 1 0. 5. 4. Ensure that the test
m odu le(s) are open-circu ited.
b) On a suitabl e, clear, sunn y day with l ittle win d, record, as a fu nction of tim e, th e cell
tem perature, th e am bient tem perature, the irrad ian ce, wind speed an d wind d irection.
c) Rej ect al l d ata taken d uring th e fol l owing con d ition s:
–
–

irrad iance bel ow 400 W ⋅ m –2 ;

in a 1 0 m in interval after the irradiance varies by m ore th an 1 0 % d u ring a d ata
coll ection ru n;