IEC TS 61836:2025

IEC TS 61836 ®
Edition 4.0 2025-11
TECHNICAL
SPECIFICATION
Solar photovoltaic energy systems - Terms, definitions and symbols

ICS 27.160  ISBN 978-2-8327-0745-6

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CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and symbols. 5
3.1 Photovoltaic cells and modules . 5
3.2 Other components . 12
3.3 Photovoltaic systems . 13
3.4 Performance parameters . 15
3.5 Measurement and testing . 17
3.6 Environmental parameters . 18
Index of terms and symbols . 20

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Solar photovoltaic energy systems -
Terms, definitions and symbols

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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shall not be held responsible for identifying any or all such patent rights.
IEC TS 61836 has been prepared by IEC technical committee 82 Solar photovoltaic energy
systems. It is a Technical Specification.
This fourth edition cancels and replaces the third edition published in 2016. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Only the basic and essential terms to be included in the IEV have been selected and defined.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
82/2446/DTS 82/2513/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/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
Since 1987, IEC TC 82 has developed international standards in the field of photovoltaic
systems to facilitate communication between experts from IEC and ISO technical committees,
industrialists and users of PV technology. The first three editions of IEC TS 61836 have brought
together the terms and definitions of the photovoltaic IEC international standards.
In 2018 the IEC TC 82 plenary meeting decided to publish the basic PV vocabulary in IEC 60050
International Electrotechnical Vocabulary and thus make the terms and definitions available
online to a wider audience including governmental, non-governmental organizations and the
international scientific and technical press.
IEC TC 82 selected 115 basic terms from more than 500 available terms to date. As only a few
terms relating to photovoltaics are currently listed in the IEV, it was decided by IEC TC 82, TC 1
Terminology and IEC Central Office to introduce in the IEV a new section 'Solar photovoltaics'
with the selected terms.
IEC TC 82 drafted the definitions according to the recommendations of Annex SJ Rules for
terminology work of the ISO/IEC Directives, IEC Supplement:2024.
The terms are listed alphabetically in six categories:
– photovoltaic cells and modules;
– other components;
– photovoltaic systems;
– performance parameters;
– measurement and testing;
– environmental parameters.
1 Scope
IEC TS 61836 covers solar photovoltaic (PV) terminology, definitions and symbols used in
IEC TC 82 international standards.
Edition 4 of IEC TS 61836 presents a selection of basic PV terms and definitions intended for
inclusion in the multilingual online International Electrotechnical Vocabulary (IEV) in
collaboration with IEC TC 1 and IEC Central Office.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and symbols
3.1 Photovoltaic cells and modules
3.1.1
active photovoltaic cell area
active PV cell area
part of the cell area designed to receive solar radiation
Note 1 to entry: Active PV cell area does not include the metallisation lines.
3.1.2
active photovoltaic module area
active PV module area
part of the total module area designed to receive solar radiation for the generation of electric
power
Note 1 to entry: Active PV module area equals the sum of the total cell area in the module.
3.1.3
amorphous silicon photovoltaic cell
a-Si photovoltaic cell
photovoltaic cell fabricated from thin layers of hydrogenated amorphous silicon as the active
photovoltaic material deposited on a foreign substrate
Note 1 to entry: Also referenced as a thin-film amorphous silicon photovoltaic cell.
Note 2 to entry: Variants of thin-film amorphous silicon include microcrystalline silicon (µc-Si), etc.
3.1.4
amorphous silicon photovoltaic module
photovoltaic module manufactured with amorphous silicon photovoltaic cells
Note 1 to entry: Also referenced as a thin-film amorphous silicon photovoltaic module.
3.1.5
anti-reflective coating
layer formed on the surface of a photovoltaic cell or the frontsheet of a photovoltaic module to
reduce solar radiation reflectance
3.1.6
backsheet
photovoltaic backsheet
sheet made of one or more layers that constitute the back of a
photovoltaic module
Note 1 to entry: The backsheet provides environmental protection and electrical insulation of the encapsulated
photovoltaic cells and circuitry.
3.1.7
back-surface field effect
BSF effect
effect where the charge carriers generated near the back side of a photovoltaic cell are collected
effectively by the inner electric field that is formed by a heavily doped zone near the rear
electrode
3.1.8
bifacial photovoltaic cell
bifacial PV cell
photovoltaic cell which allows the use of incident light from both front and rear sides
3.1.9
bifacial photovoltaic module
bifacial PV module
photovoltaic module which allows the use of incident light from both front and rear sides
3.1.10
building-integrated photovoltaic module
BIPV module
photovoltaic module that provides one or more functions of the building envelope
Note 1 to entry: If a building-integrated photovoltaic module is uninstalled, it shall be replaced by an appropriate
construction product.
3.1.11
building-integrated photovoltaics
BIPV
branch of science and technology pertaining to photovoltaic modules and arrays providing one
or more functions of the building envelope
3.1.12
busbar
metallisation line which interconnects gridlines of a photovoltaic cell
3.1.13
bypass diode
diode connected in parallel with one or more photovoltaic cells in a
photovoltaic module in the forward current direction to prevent hot spots and reduce power
losses from shaded or damaged cells
3.1.14
cadmium telluride photovoltaic cell
CdTe photovoltaic cell
CdTe cell
photovoltaic cell fabricated from thin layers of cadmium telluride as the active photovoltaic
material deposited on a foreign substrate
Note 1 to entry: The cadmium telluride photovoltaic cell has a heterojunction structure with cadmium telluride
(CdTe) and cadmium sulphide (CdS) or other materials.
3.1.15
cadmium telluride photovoltaic module
CdTe photovoltaic module
CdTe module
module manufactured with cadmium telluride photovoltaic cells
3.1.16
CIS photovoltaic cell
photovoltaic cell fabricated from thin layers of copper indium di-selenide as the active
photovoltaic material deposited on a foreign substrate
Note 1 to entry: CIS is the abbreviation of CuInSe .
Note 2 to entry: A CIS photovoltaic cell has a heterojunction structure with CIS and cadmium sulphide (CdS) or
other materials.
Note 3 to entry: A CIS cell which includes gallium is named as CIGS cell.
3.1.17
CIS photovoltaic module
photovoltaic module manufactured with copper indium di-selenide photovoltaic cells
Note 1 to entry: Also referenced as a thin-film CIS photovoltaic module.
3.1.18
concentrator photovoltaic cell
concentrator PV cell
CPV cell
photovoltaic cell specifically designed to be used under
concentrated solar radiation
Note 1 to entry: A concentrator photovoltaic cell is the core element of a concentrator photovoltaic receiver.
3.1.19
concentrator photovoltaic module
concentrator PV module
CPV module
group of concentrator photovoltaic receivers, optics, and other
related components, that concentrates solar radiation and converts it into electric energy
Note 1 to entry: Components are usually prefabricated as one unit, and the focus point is not field adjustable.
3.1.20
concentrator photovoltaics
CPV
science and technology relating to direct conversion of concentrated solar radiant energy into
electric energy
Note 1 to entry: The solar radiation could be magnified by various methods, such as reflective or refractive optics,
in dish, trough, lens or other configurations.
3.1.21
crystalline silicon photovoltaic cell
photovoltaic cell fabricated from crystalline silicon as the active photovoltaic material
Note 1 to entry: Examples are monocrystalline silicon cell and multicrystalline silicon cell.
3.1.22
crystalline silicon photovoltaic module
photovoltaic module manufactured with crystalline silicon cells
3.1.23
dark current
electric current in a photovoltaic device at zero irradiance
3.1.24
delamination
unintentional separation of layers in a photovoltaic laminate that could
affect the safety, performance or both of a photovoltaic module
3.1.25
dye-sensitized photovoltaic cell
photoelectrochemical device using dye molecules with two electrodes and an electrolyte
3.1.26
flexible photovoltaic module
photovoltaic module that is designed to be bent without physical, electrical or visual damage
3.1.27
frontsheet
PV frontsheet
sheet made of one or more transparent layers that constitute the front
of a photovoltaic module
Note 1 to entry: The frontsheet provides environmental protection and electrical insulation of the encapsulated
photovoltaic cells and circuitry.
Note 2 to entry: A common material is glass.
3.1.28
hot spot
intense localised heating occurring in a photovoltaic module when its
operating electric current exceeds the reduced short-circuit current of a shaded or faulty
photovoltaic cell or group of cells within it
Note 1 to entry: When a hot spot occurs, the affected cell or group of cells is forced into reverse bias and dissipates
power, which can cause overheating. The voltage bias or damage creates a small, localized shunt path where a large
portion of the photovoltaic module current appears.
3.1.29
light trapping
light confinement
increase of the optical path length of light in a photovoltaic cell to enhance
its efficiency
Note 1 to entry: Means of light trapping include textured surfaces and reflectors.
3.1.30
metallisation line
grid line
finger
metallic conductor on the front or back of a photovoltaic cell intended to
collect the electric current generated by the photovoltaic cell
3.1.31
monocrystalline silicon
single crystal silicon
silicon material characterized by an orderly and periodic arrangement of
atoms such that it has only one crystal orientation
3.1.32
multicrystalline silicon
crystalline silicon material with large grain sizes
Note 1 to entry: Traditionally, multicrystalline silicon grain sizes are between 1 mm to 10 mm.
Note 2 to entry: Multicrystalline silicon is often moulded as a cast ingot.
3.1.33
multijunction photovoltaic cell
photovoltaic cell consisting of multiple junctions contributing to photovoltaic conversion
Note 1 to entry: Multijunction photovoltaic cells are designed to respond to different wavelength ranges.
Note 2 to entry: Also referred to as tandem cell.
3.1.34
organic photovoltaic cell
photovoltaic cell fabricated of organic materials being polymers or small molecules (thin film
type), or both
3.1.35
photovoltaic cell
PV cell
most elementary device that makes use of the photovoltaic effect to convert solar radiant energy
into DC electric energy
Note 1 to entry: In solar photovoltaic energy system applications, another term for "photovoltaic cell" is "solar
photovoltaic cell", colloquially referred to as a "solar cell".
3.1.36
photovoltaic conversion
DC electric power generation by the photovoltaic effect
3.1.37
photovoltaic current
DC electric current generated in a photovoltaic device
3.1.38
photovoltaic device
PV device
device that makes use of the photovoltaic effect to convert solar radiant energy into DC electric
energy
Note 1 to entry: A photovoltaic device is a photovoltaic cell, a photovoltaic module or a photovoltaic array.
3.1.39
photovoltaic effect
basic physical phenomenon through which an electric potential difference is produced by the
absorption of photons
Note 1 to entry: Currently the photovoltaic effect is known to be produced by specifically designed semiconductors.
This results in the direct non-thermal conversion of radiant energy into electric energy.
3.1.40
photovoltaic encapsulant
PV encapsulant
material within the photovoltaic module that adheres the photovoltaic cells to the frontsheet or
to the backsheet, or both
3.1.41
photovoltaic laminate
PV laminate
product resulting from the lamination of the frontsheet, encapsulant, photovoltaic cells, electric
circuitry and backsheet
Note 1 to entry: The laminate, complemented by a junction box, an edge seal with or without frame and a name
plate, reaches the status of a photovoltaic module.
3.1.42
photovoltaic lamination
process of bonding together layers of different materials to form a photovoltaic laminate
Note 1 to entry: Includes the complete photovoltaic cell circuit enclosed in encapsulant materials, backsheet and
frontsheet.
3.1.43
photovoltaic material
material that can exhibit the photovoltaic effect by absorption of photons
Note 1 to entry: Examples are semiconductors specifically prepared for photovoltaic applications, such as
crystalline silicon, amorphous silicon, cadmium telluride, copper indium di-selenide compounds, etc.
3.1.44
photovoltaic module
PV module
basic DC power unit consisting of interconnected photovoltaic cells protected from the
environment
Note 1 to entry: Photovoltaic modules are assembled into strings and arrays to produce the required current and
voltage.
Note 2 to entry: A photovoltaic module is colloquially called ‘photovoltaic panel’, but this is not correct.
3.1.45
photovoltaic module maximum power
power generated by a photovoltaic module at the maximum power point
3.1.46
photovoltaic module nominal power
maximum power of a photovoltaic module under standard test conditions assigned by the
photovoltaic module manufacturer
Note 1 to entry: The photovoltaic module nominal power is the power indicated in the nameplate of the module.
3.1.47
photovoltaic panel
set of photovoltaic modules mechanically pre-assembled and electrically interconnected
Note 1 to entry: The term “photovoltaic panel” should not be used as a synonym of “photovoltaic module”.
Note 2 to entry: A photovoltaic panel is usually pre-assembled at factory level.
3.1.48
solar photovoltaic
photovoltaic
PV
qualifies the direct conversion of solar radiant energy into electric energy
Note 1 to entry: Examples are photovoltaic cell, photovoltaic module, photovoltaic array, photovoltaic system,
photovoltaic power plant.
Note 2 to entry: By extension, adjective that can be applicable to objects or events related to the photovoltaic
energy conversion. Examples are photovoltaic inverter, solar photovoltaic conference, photovoltaic handbook.
3.1.49
solar photovoltaic energy
photovoltaic energy
PV energy
electric energy generated by the photovoltaic conversion of solar radiant energy
3.1.50
solar photovoltaics
photovoltaics
PV
science and technology relating to direct conversion of solar radiant energy into electric energy
3.1.51
thin film photovoltaic cell
photovoltaic cell fabricated from thin layers of semiconductor material deposited on a foreign
substrate
Note 1 to entry: Examples are amorphous silicon cell, cadmium telluride cell, CIS cell, etc.
Note 2 to entry: The substrate is usually a glass pane with adapted optical properties.
3.1.52
total photovoltaic cell area
area of the front surface of a photovoltaic cell as defined by its outer edges
Note 1 to entry: Total cell area includes the area of any metallisation lines.
Note 2 to entry: Total cell area is preferred for reporting cell efficiency.
3.1.53
total photovoltaic module area
area of the front surface of a photovoltaic module as defined by its outer edges
Note 1 to entry: Total module area includes the total area of the photovoltaic cells plus the area of space not
covered by the cells. The area of the front surface of the frame (if any) is included.
Note 2 to entry: Total module area is preferred for reporting module efficiency.
3.1.54
transparent conducting oxide
TCO
material with high electrical conductivity and high optical transmissivity
Note 1 to entry: It is used as a thin film electrode for some photovoltaic cell or module technologies.
Note 2 to entry: Common materials are tin oxide and zinc oxide.
3.1.55
transparent electrode
thin film electrode with high electrical conductivity and high optical
transmissivity used in photovoltaic device technologies
Note 1 to entry: Common materials are transparent conducting oxides.
3.1.56
wafer-based photovoltaic cell
photovoltaic cell fabricated from a wafer of crystalline material
Note 1 to entry: Examples are monocrystalline silicon and multicrystalline silicon cell.
3.2 Other components
3.2.1
blocking diode
diode connected in series with photovoltaic modules, strings and sub-arrays to block reverse
electric current
Note 1 to entry: Blocking diodes should not be used for overcurrent protection.
3.2.2
DC-DC converter
DC conditioning unit
DC to DC power conversion equipment connected to individual
photovoltaic modules or photovoltaic strings to modify the voltage or current, or both
3.2.3
dual-axis solar tracker
system that follows the sun position with two rotation axes
Note 1 to entry: Dual-axis solar trackers are used to accurately maintain alignment to the sun.
3.2.4
inverter
PV inverter
power conversion equipment that changes direct electric current to
single-phase or polyphase alternating current and features certain functions specific to
photovoltaic systems
Note 1 to entry: A PV inverter can include maximum power point tracking, monitoring and grid services functions.
Note 2 to entry: A PV inverter operates in grid-connected or stand-alone mode.
3.2.5
photovoltaic cable
electrical cable specifically designed for the purpose of carrying electric current from
photovoltaic devices
Note 1 to entry: A photovoltaic cable endures conditions such as high temperatures, long-term UV exposure, long-
term abrasion by wind, damage by animals.
3.2.6
photovoltaic combiner box
enclosure where photovoltaic strings or photovoltaic sub-arrays are electrically connected
Note 1 to entry: Types of photovoltaic combiner boxes are photovoltaic string combiner box, photovoltaic sub-array
combiner box.
Note 2 to entry: Photovoltaic combiner box can also contain overcurrent protection or disconnection devices, or
both.
3.2.7
photovoltaic module junction box
protected enclosure of a photovoltaic module where internal circuits and output cables are
electrically connected
Note 1 to entry: A photovoltaic module junction box provides an appropriate protection against external influences
and environment.
Note 2 to entry: A photovoltaic module junction box can contain bypass diodes.
3.2.8
photovoltaic string
PV string
circuit of series-connected photovoltaic modules designed to provide a
required voltage
3.2.9
photovoltaic supply cable
cable connecting the power conversion equipment to an electrical distribution circuit or to a load
3.2.10
power conversion equipment
PCE
electric device of a photovoltaic system converting one kind of electric
p
...