IEC TS 63140:2021

Photovoltaic (PV) modules - Partial shade endurance testing for monolithically integrated products

IEC TS 63140:2021 provides test methods for quantifying the permanent change in a monolithically integrated PV module’s power output that may result from some potential partial shade conditions. Three tests are available, representing conditions of use, misuse, and most severe misuse. This document is applicable to monolithically integrated PV modules with one series-connected cell group or with multiple series-connected cell groups that are in turn connected in parallel. This document is not applicable to PV modules formed by the interconnection of separate cells.

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General Information

• Status: Published
• Publication Date: 27-Apr-2021
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 82 - Solar photovoltaic energy systems
• Drafting Committee: WG 2 - TC 82/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 28-Apr-2021
• Completion Date: 31-May-2021

Overview

IEC TS 63140:2021 - Photovoltaic (PV) modules - Partial shade endurance testing for monolithically integrated products - defines accelerated test methods to quantify permanent power loss in monolithically integrated PV modules caused by partial shading. The Technical Specification provides three selectable tests that represent normal use, misuse, and most severe misuse conditions. It is applicable to modules made by monolithic integration (cells built on a common substrate/superstrate and scribed during fabrication) with one series-connected cell group or multiple series-connected groups connected in parallel. It is not applicable to modules assembled from separately interconnected cells.

Key topics and technical requirements

• Test objective: Excite non-uniform current flow and reverse bias in shaded cells to reveal permanent degradation (shunts, localized heating) and quantify consequent drop in power output.
• Three test types:
  • Use (U) test: Check manufacturer documentation for specific warning text; if present, no physical test is required. If absent, proceed to the Misuse (M) test.
  • Misuse (M) test: Simulates a person walking past the module in bright conditions using a human-sized mask that blocks about 90% of incident light; up to 1 m of the shadow can overlap the module height.
  • Most Severe Misuse (SM) test: Simulates a narrow cleaning tool passing across the module, with a mask that blocks about 100% of incident light across the full module height.
• Test conditions: High-irradiance, repeated mask movement while the module operates under current flow (accelerated conditions intended to emulate extended outdoor stress).
• Apparatus & measurements:
  • Stabilization per IEC 61215-2 MQT 19.
  • I‑V curve measurement per IEC 61215-2 MQT 02 and IEC 60904‑1.
  • Constant-current operation equipment able to sink/source up to 1.5× module nameplate I_mp (requirements depend on presence of bypass diodes).
• Limitations: These procedures are not equivalent to IEC 61215‑2 hot‑spot endurance testing and do not replace safety qualification standards.

Applications and who should use it

• PV module manufacturers: design verification and robustness assessment for monolithic modules against partial shading and misuse scenarios.
• Independent test laboratories & certification bodies: evaluate shade-induced degradation and provide evidence for product qualification or failure analysis.
• Quality, reliability and warranty engineers: assess long-term performance risk from partial shading and inform warranty policies.
• System integrators and asset owners: understand how monolithic modules respond to common shading events and cleaning practices.

Related standards

• IEC 61215-2 (Design qualification and test procedures)
• IEC 61730-2 (PV module safety qualification)
• IEC 60904 series (I‑V measurement and solar simulator requirements)
• IEC TS 61836 / IEC TS 60904-13 (definitions, electroluminescence)

Keywords: IEC TS 63140, partial shade endurance testing, monolithically integrated PV modules, partial shading, PV module testing, misuse test, most severe misuse, shade-induced degradation.

Standards Content (Sample)

IEC TS 63140 ®
Edition 1.0 2021-04
TECHNICAL
SPECIFICATION
colour
inside
Photovoltaic (PV) modules – Partial shade endurance testing for monolithically
integrated products
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IEC TS 63140 ®
Edition 1.0 2021-04
TECHNICAL
SPECIFICATION
colour
inside
Photovoltaic (PV) modules – Partial shade endurance testing for monolithically

integrated products
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-9741-4

– 2 – IEC TS 63140:2021 © IEC 2021
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Principle . 7
5 Apparatus . 8
6 Procedure . 10
6.1 General . 10
6.2 Use test (test U) . 10
6.3 Misuse test (test M) and most severe misuse test (test SM) . 11
6.3.1 General . 11
6.3.2 Initial measurements . 11
6.3.3 Misuse test (test M) . 11
6.3.4 Most severe misuse test (test SM) . 12
6.3.5 Final measurements . 13
7 Test report . 14

Figure 1 – Selection of the three available tests . 7
Figure 2 – Dimensions of the mask for test M (left) and the mask for test SM (right) . 10
Figure 3 – Illustration of test M, showing the movement of the fixed-size mask across
example modules of three different sizes . 12
Figure 4 – Illustration of test SM, showing the overlap of the mask with the module’s
full height and the movement of the mask across example modules of three different
sizes . 13

Table 1 – Test types available in this document . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PHOTOVOLTAIC (PV) MODULES – PARTIAL SHADE ENDURANCE
TESTING FOR MONOLITHICALLY INTEGRATED PRODUCTS

FOREWORD
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IEC TS 63140 has been prepared by IEC technical committee 82: Solar photovoltaic energy
systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
82/1804/DTS 82/1836/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.

– 4 – IEC TS 63140:2021 © IEC 2021
The committee has decided that the contents of this document will remain unchanged until the
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• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
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of its contents. Users should therefore print this document using a colour printer.

PHOTOVOLTAIC (PV) MODULES – PARTIAL SHADE ENDURANCE
TESTING FOR MONOLITHICALLY INTEGRATED PRODUCTS

1 Scope
This document provides test methods for quantifying the permanent change in a monolithically
integrated PV module’s power output that may result from some potential partial shade
conditions. Three tests are available, representing conditions of use, misuse, and most severe
misuse. This document is applicable to monolithically integrated PV modules with one series-
connected cell group or with multiple series-connected cell groups that are in turn connected in
parallel. This document is not applicable to PV modules formed by the interconnection of
separate cells.
With regard to shading, PV module documentation varies significantly by manufacturer. The
physical tests prescribed in this document are applied without regard to manufacturer
documentation or warranty policy, which may forbid certain shadows. The tests may therefore
go beyond intended use, testing a module’s response to misuse. The tests are accelerated tests.
They are intended to excite similar levels of stress as shadows that are possible during an
extended period of outdoor service. The tests represent adverse shadow scenarios, but not
necessarily the worst case scenario, which varies by product. The procedures are performed
repeatedly and in high-irradiance conditions; shadows occurring only one time or in low-
irradiance conditions are likely to cause less damage. This test procedure does not
comprehensively evaluate the efficacy or completeness of manufacturer recommendations.
This test procedure is not equivalent to, and is not intended to replace, the hot-spot endurance
test in IEC 61215-2. The safety aspects of partial shading of PV modules are covered by
IEC 61730-2 MST 22 and IEC 61215-2 MQT 09.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
IEC 60904-1, Photovoltaic devices – Part 1: Measurement of photovoltaic current-voltage
characteristics
IEC 60904-2, Photovoltaic devices – Part 2: Requirements for photovoltaic reference devices
IEC 60904-9, Photovoltaic devices – Part 9: Classification of solar simulator characteristics
IEC 60904-10, Photovoltaic devices – Part 10: Methods of linear dependence and linearity
measurements
IEC TS 60904-13, Photovoltaic devices – Part 13: Electroluminescence of photovoltaic modules
IEC 61215-2:2021, Terrestrial photovoltaic (PV) modules – Design qualification and type
approval – Part 2: Test procedures
IEC 61730-2, Photovoltaic (PV) module safety qualification – Part 2: Requirements for testing
IEC TS 61836, Solar photovoltaic energy systems – Terms, definitions and symbols

– 6 – IEC TS 63140:2021 © IEC 2021
IEC 61853-1, Photovoltaic (PV) module performance testing and energy rating – Part 1:
Irradiance and temperature performance measurements and power rating
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC TS 61836 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp.
3.1
intended use
use of a product, process or product-related service in accordance with the information for use
provided by the product manufacturer
3.2
misuse
use of a product, process or product-related service in a way not intended by the product
manufacturer as described in the product manufacturer’s product-specific manuals and
operating instructions
Note 1 to entry: Module warranties are often voided in cases of misuse.
3.3
monolithically integrated
composed of multiple solar cells built on the same substrate or superstrate and integrated
through scribing processes during fabrication
3.4
cell pitch
distance between successive repetitions of the monolithic integration pattern
3.5
module height
dimension of the module when measured parallel to the cell integration scribe lines
3.6
module width
dimension of the module when measured perpendicular to the cell integration scribe lines
3.7
string current
current that would pass in a long string of uniformly illuminated modules under the present
irradiance conditions and at 25 °C
Note 1 to entry: String current is defined by:

where
I is the current at maximum power listed on the module nameplate, and
mp,STC
E is the plane-of-array irradiance.
POA
Note 2 to entry: This formula is strictly valid only for linear devices, as defined in IEC 60904-10. It is acceptable for
use in the range of irradiances and temperatures used in this document.
4 Principle
Monolithically integrated PV modules contain multiple PV cells connected in series. When
illuminated and non-illuminated cells are connected in series, the non-illuminated cells can
operate in reverse bias. In combination with nonuniformities in the device, this reverse bias can
lead to highly nonuniform current flow, localized heating, and the formation of permanent shunts.
The test procedures excite this nonuniform current flow and quantify the resulting permanent
change in PV module power output.
Three test types are available, summarized in Table 1. Any of the tests may be requested by a
requestor. The U test verifies the presence of specific warning text in manufacturer
documentation. If this text is absent, test M is performed, whether or not it was requested. Test
M approximates a person repeatedly walking past the module in sunny conditions. Test SM
approximates a narrow
...