IEC TS 62257-100:2022

Renewable energy off-grid systems - Part 100: Overview of the IEC 62257 series

IEC TS 62257-100:2022 introduces the entire series regarding off-grid renewable energy and hybrid products and systems most commonly used for rural applications and access to electricity. This document provides a guide for facilitating the reading and the use of the IEC 62257 series for setting up off-grid electrification in developing countries or in developed countries, the only difference being the level of service and the needed quantity of energy that the customer can afford.
This document outlines the organization of documents within the updated IEC 62257-xxx series published in 2022 and later, including utilization of a new 3-digit part numbering scheme, grouped into topics and subtopics.

General Information

• Status: Published
• Publication Date: 18-Oct-2022
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 82 - Solar photovoltaic energy systems
• Drafting Committee: JWG 1 - TC 82/JWG 1
• Current Stage: PPUB - Publication issued
• Start Date: 14-Nov-2022
• Completion Date: 19-Oct-2022

Relations

• Revises: IEC TS 62257-1:2015 - Recommendations for renewable energy and hybrid systems for rural electrification - Part 1: General introduction to IEC 62257 series and rural electrification
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC TS 62257-100
®

Edition 1.0 2022-10
TECHNICAL
SPECIFICATION



Renewable energy off-grid systems –
Part 100: Overview of the IEC 62257 series
IEC TS 62257-100:2022-10(en)

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IEC TS 62257-100

®


Edition 1.0 2022-10




TECHNICAL



SPECIFICATION



















Renewable energy off-grid systems –

Part 100: Overview of the IEC 62257 series


























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ELECTROTECHNICAL


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ICS 27.160 ISBN 978-2-8322-5853-8




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– 2 – IEC 62257-100:2022 © IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
4 Background to renewable energy and hybrid off-grid systems . 9
4.1 General . 9
4.2 Packaged and custom renewable energy off-grid and hybrid systems . 9
4.3 Project management and tendering . 10
5 Organization and overview of the IEC 62257 series . 10
5.1 General . 10
5.2 -100 Series: Introduction and project management . 11
5.3 -200 Series: System design and installation . 12
5.4 -300 Series: Energy system components . 12
5.5 -400 Series: User equipment and appliances . 13
5.6 -500 Series: Stand-alone products and packaged kits . 13
6 Example case studies for users of this series . 14
6.1 General . 14
6.2 Example case study #1: Manufacturer of component for an off-grid wind
system . 14
6.3 Example case study #2: Certification testing lab for solar lanterns . 15
6.4 Example case study #3: Importer of solar products . 15
6.5 Example case study #4: Agency developing regional-level RFQ for school
PV systems . 15
6.6 Example case study #5: Installer of small PV systems . 15
6.7 Example case study #6: Retailer of solar lanterns and small solar kits . 16
6.8 Example case study #7: Off-grid system owners . 16
Annex A (informative) Reorganization of the IEC 62257 series . 17
Bibliography . 19

Table 1 – Subtopics within the IEC 62257 series . 7
Table 2 – Organization of main topics within IEC 62257: Renewable energy off-grid
systems . 11
Table 3 – Subtopics within the -100 series on Introduction and project management . 11
Table 4 – Subtopics within the -200 series on System design and installation . 12
Table 5 – Subtopics within the -300 series on Energy system components . 12
Table 6 – Subtopics within the -400 series on User equipment and appliances . 13
Table 7 – Subtopics within the -500 series on Stand-alone products and packaged kits . 13
Table A.1 – Look-up table for users of prior versions of IEC 62257-x documents to
potentially relevant subtopic(s) within the new IEC 62257-xxx scheme . 17

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IEC 62257-100:2022 © IEC 2022 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

RENEWABLE ENERGY OFF-GRID SYSTEMS –

Part 100: Overview of the IEC 62257 series

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC TS 62257-100 has been prepared by IEC technical committee 82: Solar photovoltaic energy
systems. It was developed in cooperation with other IEC technical committees and
subcommittees dealing with renewable energies and related matters, namely IEC technical
committee 21: Secondary cells and batteries, subcommittee 21A: Secondary cells and batteries
containing alkaline or other non-acid electrolytes, IEC technical committee 64: Electrical
installations and protection against electric shock, IEC technical committee 88: Wind energy
generation systems. It is a Technical Specification.
This first edition of IEC TS 62257-100 cancels and replaces the third edition of IEC TS 62257-1
issued in 2015. It constitutes a major technical revision. This new edition of the introductory
document transitions the entire series to a 3-digit numbering scheme. The overall numbering
scheme is presented, including planned topics and sub-topics, to assist in organizing future
documents and to differentiate the new documents from those under the former scheme. This
major re-organization and update of the series was determined by JWG1 to be necessary to
accommodate major advances within this subject area.
The main technical changes with regard to the previous edition’s introductory document,
IEC TS 62257-1, are as follows:

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– 4 – IEC 62257-100:2022 © IEC 2022
– describe the major updates for the IEC 62257 series;
– new simplified title for the series “Renewable energy off-grid systems”, which will precede
individual part numbers;
– provide an introduction to the entire series, including the updated organization and planned
content of the IEC 62257 series;
– add example user case studies to assist various users in selecting relevant parts within the
series;
– removal of content replicated in other documents and relocation of some information to other
planned documents in this series;
– addition of general information on access to electricity;
– additional information on managing a renewable energy off-grid project including tendering;
– removal of an annex containing definitions, originally intended to cover all documents in the
series; future documents published under this new scheme will contain definitions for
individual documents within that document itself.
This technical specification should be used in conjunction with the other documents of the
IEC 62257 series, as relevant.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
82/2028/DTS 82/2066/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.
A list of all parts in the IEC 62257 series, published under the general title Renewable energy
off-grid systems, can be found on the IEC website.
Future standards in this series will carry the new general title and three-digit numbering. Titles
and numbers of existing standards in this series will be updated at the time of their next edition.
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,
• replaced by a revised edition, or
• amended.

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IEC 62257-100:2022 © IEC 2022 – 5 –
INTRODUCTION
The IEC 62257 series provides technical standardization to different stakeholders (including
but not limited to project developers, financing agencies, testing agencies, installers, etc.)
involved in electrification projects for access to electricity for those not solely connected to the
regional grid, through the setting up of off-grid renewable energy and hybrid systems (including
micro-grids) with a voltage less than or equal to 1 000 V for AC (alternating current) or a voltage
less than or equal to 1 500 V for DC (direct current).
Access to electricity is one of the predominant policy actions designed to increase the well-
being of populations, together with access to clean water, improved healthcare, education,
personal advancement and economic development. Increasing access to electricity through
utilization of renewable off-grid electricity also directly or indirectly supports various United
Nations Sustainability Development Goals (https://sdgs.un.org/goals), depending on the
application.
Several strategies can be adopted to implement electrification and improve access to electricity
in rural and urban settings, including the ability for connection to a national or regional electricity
grid. The IEC 62257 series applies to cases where the utility grid is too far away, the individual
demand centres are too small to make grid access economical: off-grid solutions provide an
economical option, and where autonomous power systems can be used to supply these
services.
These technical specifications are used to:
a) choose the right solution for the right place with the optimal technology,
b) design, purchase and install the product(s) and/or system to optimal compliancy,
c) operate and maintain the system.
The IEC 62257 technical specifications focus on enabling access to electricity by concentrating
on, but not being specific to, developing countries. This series shall not be considered as all-
inclusive for access to electricity. That means that the technical specifications could be used
for rural electrification, also for electrification of remote sites in developed countries, or any
requirement for electricity access that cannot be met by attaching solely to the national utility
grid. They promote the use of renewable energies, but at this time they do not deal with clean-
energy mechanisms development (CO2 emission, carbon credit, etc.). The series does allow
for other types of energy, such as diesel generators, to be included as part of a hybrid renewable
energy off-grid system.
This consistent set of documents may be considered as a whole, with different parts focusing
on specific aspects of renewable energy off-grid systems. However, several parts are intended
to be read as stand-alone documents depending on their intended application.
IEC TS 62257-100 provides an overview of the various topics covered by this series.
Additionally, the content and scopes of individual documents, available at the website
webstore.iec.ch, provide potential users with the intended application for each document. For
further information on planned documents to be published under the new IEC 62257 numbering
scheme, IEC TC82 committee members may refer to the annex in the JWG1 Program of Work
circulated after each JWG1 meeting, or to the Planned Work Programme on the www.iec.ch
TC82 website.
One of the main objectives of this series is to provide the minimum sufficient recommendations,
including items for safety, sustainability of systems and at the lowest life cycle cost, relevant to
the renewable energy and hybrid off-grid systems field of application.

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RENEWABLE ENERGY OFF-GRID SYSTEMS –

Part 100: Overview of the IEC 62257 series

1 Scope
This part of the IEC 62257 series introduces the entire series regarding off-grid renewable
energy and hybrid products and systems most commonly used for rural applications and access
to electricity.
This Part 100 document provides a guide for facilitating the reading and the use of the
IEC 62257 series for setting up off-grid electrification in developing countries or in developed
countries, the only difference being the level of service and the needed quantity of energy that
the customer can afford.
This Part 100 document introduces the series. It focuses on the planned document organization
and numbering structure, including a description of each topic and subtopic grouping. It contains
a brief overview of the project management and tendering process. It also contains a brief
overview of the concept of “access to electricity” and some of the types of renewable energy
off-grid and hybrid systems. This document has several examples of case studies for various
user groups, to assist them in utilizing the updated series. Additionally, it contains an
informative Annex A to assist users of prior versions of the IEC 62257-x series in locating
content within the updated IEC 62257-xxx series.
This document outlines the organization of documents within the updated IEC 62257-xxx series
published in 2022 and later, including utilization of a new 3-digit part numbering scheme,
grouped into topics and subtopics.
This series is anticipated to be of interest to the following renewable energy off-grid and hybrid
system stakeholders:
• manufacturers
• testing and certification labs
• equipment distributors, importers, and bulk buyers
• government regulators, inspection, certification, safety, customs and trade agencies
• agencies developing regional-level solar lantern / kit programs
• agencies developing RFQs (Request for Quotations) for systems
• system designers, engineers, project implementers, contractors, supervisors
• installers of small PV and storage
• installers of small wind systems
• installers of large hybrid systems with multiple users
• system owners, residents, operators, maintenance personnel.
The document part numbers to be assigned within this updated IEC 62257-xxx series will be
grouped into topics as follows:
• Parts -1xx: Introduction and project management
• Parts -2xx: System design and installation
• Parts -3xx: Energy system components
• Parts -4xx: User equipment and appliances
• Parts -5xx: Stand-alone products and packaged kits.

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IEC 62257-100:2022 © IEC 2022 – 7 –
To assist users in navigating the documents within the revised IEC 62257 series, this
introductory -100 document presents how the documents will be further organized into the
following subtopics, see Table 1.
Table 1 – Subtopics within the IEC 62257 series
Subtopic
Main topic Subtopic
Part #
-100 Overview of the IEC 62257 series
-11x Project management framework
Introduction and project management
-12x Tendering and evaluation
-13x Preliminary assessments
-20x Design
-21x Installation
System design and installation
-22x Tools for installation
-23x Competency evaluation
-30x Generators and energy conversion
-31x Photovoltaic modules
-32x Wind turbines
-33x Generator sets
Energy system components
-34x Batteries and battery management systems
-35x Inverters
-36x Balance of system components – DC
-37x Balance of system components – AC
-40x Off-grid loads
User equipment and appliances
-41x Lighting
Stand-alone products and packaged kits -50x Stand-alone renewable energy products

Refer to the website address www.iec.ch for a list of published documents.
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 TS 61836:2016, Solar photovoltaic energy systems – Terms, definitions and symbols
NOTE Refer to http://www.iec.ch for a list of the current available documents within the IEC 62257 series. Note that
documents developed under the updated series referred to in this document have 3-digit part numbers, e.g.
IEC TS 62257-100.
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms, definitions and abbreviations given in
IEC TS 61836 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:

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• IEC Electropedia: IEC 60050, available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE Terms and abbreviations, which appear within individual parts of the IEC 62257-xxx series, are defined in
Clause 3 of the document in which the terms appear. Wherever possible, the document will adopt terms without
modification from the PV Glossary, IEC TS 61836, or the IEC Electropedia, at http://www.electropedia.org/. If the
existing definition is deemed inadequate, the existing definition may be modified or a new definition drafted. This
approach to definitions will support standardization of terms used within the renewable energy off-grid industry.
3.1
competency
demonstration of appropriate technical knowledge and relevant skills to perform the designated
tasks and responsibilities
3.2
generator
apparatus that converts non-electric energy into electric energy
Note 1 to entry: A generator does not include energy storage devices or power conditioners.
3.3
hybrid system
energy system comprised of multiple types of energy sources
Note 1 to entry: A source of energy may occasionally be the regional grid. A regional grid source introduces
additional challenges addressed by other standards.
Note 2 to entry: A source of energy may include energy storage devices.
3.4
regional grid
regional electrical grid
national grid
national electrical grid
electrical grid
utility grid
electric power network
main grid
electrical distribution and/or transmission system for which an electrical utility is responsible
Note 1 to entry: Typically of regional or national scale to cover a large geographical area.
Note 2 to entry: Typically comprised of multiple sources of generation and loads.
[SOURCE: IEC TS 61836:2016, 3.3.29 and 3.3.29.2, modified to combine definitions into single
term, to add common alternate terms, and to add Notes.]
3.5
offgrid
off-grid
off grid
electrified solely by stand-alone operation of the energy system, which may include storage and
micro/mini-grids, and not in parallel with a utility grid
[SOURCE: IEC TS 61836:2016, 3.3.55.7 and 3.3.55.9, modified to combine definitions into
single term, to add common alternate terms, and to include systems in addition to PV.]
3.6
PV
solar photovoltaic

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IEC 62257-100:2022 © IEC 2022 – 9 –
3.7
renewable energy
primary energy the source of which is constantly replenished and will not become depleted
Note 1 to entry: Examples of renewable energy are: wind, solar, geothermal, hydropower.
Note 2 to entry: Fossil fuels are non-renewable.
[SOURCE: IEC 60050-617:2009, 617-04-11]
3.8
ESMAP
World Bank ESMAP Tier Structure
the Energy Sector Management Assistance Program is a global knowledge and technical
assistance program administered by the World Bank
4 Background to renewable energy and hybrid off-grid systems
4.1 General
Where connection to a national or regional electricity grid is not possible or reliable enough to
provide the desired level of electrification, renewable energy off grid and hybrid systems are
typically used. These autonomous renewable energy and hybrid systems are able to provide
electricity without connection to the larger utility grid.
Using renewable energy off-grid and hybrid systems to create “access to electricity” applies to
cases where the regional grid is too far away and/or too costly for the user(s) to connect to the
regional grid, and where autonomous power systems can be used to supply these services.
The amount of electricity available, and the duration it is available for, are dependent upon the
generator type and size, storage available, system design, energy management techniques,
and the user’s demand profile.
For successful implementation of a project, knowledge of project management and tendering
requirements may be required, in addition to technical knowledge.
4.2 Packaged and custom renewable energy off-grid and hybrid systems
There are 2 main types of renewable energy off-grid and hybrid systems available, both of which
support access to electricity:
– packaged products;
– custom systems.
For small and simple applications, for example to provide light to allow students to study or to
provide for simple household needs, packaged solutions are available. These range from small,
handheld, integrated solar lantern products complete with solar PV module, battery, and lamp,
to solar PV home kits which have all components for self-installation (except for the household’s
loads). These packaged solutions have been evaluated for compliance for their intended use
per documents in this series.
NOTE Solar pumping stations which integrate a water pump driven directly by solar photovoltaics are evaluated to
IEC 62253.
Off-grid systems are designed to supply power to demand points located in areas that cannot
be easily (economically) connected to regional grids. These systems are customized to meet
the local requirements and include hybrid and micro-grid options.
In most cases, these systems would provide the electrical demands for:

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– individual homes;
– specific processes (examples: public pumping, battery charging centre, aquaculture);
– collective/communal facilities (examples: public lighting, schools, health and care centre,
places of worship, administrative buildings);
– business activities (examples: workshops, micro industry, trade, stores);
– isolated villages.
These systems could either:
– supply electricity to a single load or single user;
– supply electricity to multiple users over a larger distance.
Systems for both end-use applications may be comprised of a single generator of a single type,
multiple generators of a single type, or multiple types of generators. They may be provided with
or without storage (often a chemical battery but could be water (hydro) or other type of storage).
The user loads may be included as part of the system, or connection points may be provided to
allow users to connect their own loads.
There are limits to the energy produced by the system based on the design criteria, available
resources, and anticipated use p
...