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

IEC TS 62257-1:2015(E) introduces a methodology for implementing rural electrification using autonomous hybrid renewable energy systems. It also provides a guide for facilitating the reading and the use of the IEC 62257 series for setting up decentralized rural electrification in developing countries or in developed countries. The IEC 62257 series is designed as follows:
- Parts 2 to 6 are methodological supports for the management and implementation of projects;
- Parts 7 to 12 are technical specifications for individual or collective systems and associated components.
This publication is to be read in conjunction with IEC 62257 series.

General Information

• Status: Replaced
• Publication Date: 08-Oct-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 82 - Solar photovoltaic energy systems
• Drafting Committee: JWG 1 - TC 82/JWG 1
• Current Stage: DELPUB - Deleted Publication
• Start Date: 01-Apr-2019
• Completion Date: 19-Oct-2022

Relations

• Revised: IEC TS 62257-100:2022 - Renewable energy off-grid systems - Part 100: Overview of the IEC 62257 series
• Effective Date: 05-Sep-2023
• Revises: IEC TS 62257-1:2013 - Recommendations for small 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 62257-1 ®
Edition 3.0 2015-10
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for renewable energy and hybrid systems for rural
electrification –
Part 1: General introduction to IEC 62257 series and rural electrification

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]

CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC TS 62257-1 ®
Edition 3.0 2015-10
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for renewable energy and hybrid systems for rural

electrification –
Part 1: General introduction to IEC 62257 series and rural electrification

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-2914-9

– 2 – IEC TS 62257-1:2015  IEC 2015

CONTENTS
FOREWORD . 3

INTRODUCTION . 5

1 Scope . 6

2 Normative references . 6

3 Terms, definitions and abbreviations . 7

4 Methodology for rural electrification using hybrid renewable energy systems . 8

4.1 Rural electrification: which solution to choose? . 8
4.2 Decentralized electrification requiring a range of systems . 10
5 How to use the IEC 62257 series for a rural electrification project . 12
5.1 Overview. 12
5.2 Review of the IEC 62257 series: links with the phases of a rural
electrification project (see Table 3) . 15
5.2.1 Opportunity study . 15
5.2.2 Specification of a project . 15
5.2.3 Feasibility study of a project . 17
5.2.4 Detailed technical studies . 18
5.2.5 Implementation of a project. 19
5.2.6 Validation of a project . 20
5.2.7 On field operation . 21
Annex A (normative) Terms, definitions and abbreviations in use in the IEC 62257
series. 23

Figure 1 – Example of electrification progress following a master plan methodology . 9
Figure 2 – Example of electrification of a village using both CESs and IESs . 10
Figure 3 – Contractual relationship between project participants – (IEC TS 62257-
3:2015, Figure 1) . 16
Figure 4 – Example of the content of a non-technical preliminary study – (IEC TS
62257-2:2015, Figure 1) . 18
Figure 5 – TN-C-S system – (IEC TS 62257-5:2015, Figure B.2) . 19
Figure 6 – Phase A battery endurance test – (IEC TS 62257-8-1:2007, Figure 2) . 20
Figure 7 – Test 3, operating cycles – (IEC TS 62257-9-6:2008, Figure 3) . 21

Table 1 – Some advantages and disadvantages of the proposed single and multiple
user systems . 11
Table 2 – Contents of the 62257 series . 13
Table 3 – Utilization of the different parts of the IEC 62257 series according to the
main project phases . 14
Table 4 – Combined categorization – (IEC TS 62257-2:2015, Table C.1) . 17
Table 5 – Service specification (example) – (IEC TS 62257-2:2015, Table C.2) . 17
Table 6 – Verification of the adherence to commitments – (IEC TS 62257-6:2015,

Table 8) . 21
Table 7 – AOMR participant involvement – (IEC TS 62257-6:2015, Table 3) . 22

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
RECOMMENDATIONS FOR RENEWABLE ENERGY

AND HYBRID SYSTEMS FOR RURAL ELECTRIFICATION –

Part 1: General introduction to IEC 62257 series and rural electrification

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 co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.

The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 62257-1, which is a technical specification, 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

– 4 – IEC TS 62257-1:2015  IEC 2015

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 turbines).

This third edition cancels and replaces the second edition issued in 2013. It constitutes a

technical revision.
The main technical changes with regard to the previous edition are as follows:

– Redefine the maximum AC voltage from 500 Va.c. to 1 000 Va.c., the maximum DC

voltage from 750 Vd.c. to 1 500 Vd.c. and removal of the limitation of 100 kVA system

size. Hence the removal of the word “small” in the title and related references in this
technical specification.
This technical specification shall be used in conjunction with the other documents of the
IEC 62257 series.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
82/942/DTS 82/979/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62257 series, published under the general title Recommendations
for renewable energy and hybrid systems for rural electrification, can be found on the IEC
website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed
...

IEC TS 62257-1 ®
Edition 3.0 2015-10
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for renewable energy and hybrid systems for rural
electrification –
Part 1: General introduction to IEC 62257 series and rural electrification
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC TS 62257-1 ®
Edition 3.0 2015-10
TECHNICAL
SPECIFICATION
colour
inside
Recommendations for renewable energy and hybrid systems for rural

electrification –
Part 1: General introduction to IEC 62257 series and rural electrification

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-2914-9

– 2 – IEC TS 62257-1:2015  IEC 2015
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviations . 7
4 Methodology for rural electrification using hybrid renewable energy systems . 8
4.1 Rural electrification: which solution to choose? . 8
4.2 Decentralized electrification requiring a range of systems . 10
5 How to use the IEC 62257 series for a rural electrification project . 12
5.1 Overview. 12
5.2 Review of the IEC 62257 series: links with the phases of a rural
electrification project (see Table 3) . 15
5.2.1 Opportunity study . 15
5.2.2 Specification of a project . 15
5.2.3 Feasibility study of a project . 17
5.2.4 Detailed technical studies . 18
5.2.5 Implementation of a project. 19
5.2.6 Validation of a project . 20
5.2.7 On field operation . 21
Annex A (normative) Terms, definitions and abbreviations in use in the IEC 62257
series. 23

Figure 1 – Example of electrification progress following a master plan methodology . 9
Figure 2 – Example of electrification of a village using both CESs and IESs . 10
Figure 3 – Contractual relationship between project participants – (IEC TS 62257-
3:2015, Figure 1) . 16
Figure 4 – Example of the content of a non-technical preliminary study – (IEC TS
62257-2:2015, Figure 1) . 18
Figure 5 – TN-C-S system – (IEC TS 62257-5:2015, Figure B.2) . 19
Figure 6 – Phase A battery endurance test – (IEC TS 62257-8-1:2007, Figure 2) . 20
Figure 7 – Test 3, operating cycles – (IEC TS 62257-9-6:2008, Figure 3) . 21

Table 1 – Some advantages and disadvantages of the proposed single and multiple
user systems . 11
Table 2 – Contents of the 62257 series . 13
Table 3 – Utilization of the different parts of the IEC 62257 series according to the
main project phases . 14
Table 4 – Combined categorization – (IEC TS 62257-2:2015, Table C.1) . 17
Table 5 – Service specification (example) – (IEC TS 62257-2:2015, Table C.2) . 17
Table 6 – Verification of the adherence to commitments – (IEC TS 62257-6:2015,

Table 8) . 21
Table 7 – AOMR participant involvement – (IEC TS 62257-6:2015, Table 3) . 22

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RECOMMENDATIONS FOR RENEWABLE ENERGY
AND HYBRID SYSTEMS FOR RURAL ELECTRIFICATION –

Part 1: General introduction to IEC 62257 series and rural electrification

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 co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 62257-1, which is a technical specification, 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

– 4 – IEC TS 62257-1:2015  IEC 2015
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 turbines).
This third edition cancels and replaces the second edition issued in 2013. It constitutes a
technical revision.
The main technical changes with regard to the previous edition are as follows:
– Redefine the maximum AC voltage from 500 Va.c. to 1 000 Va.c., the maximum DC
voltage from 750 Vd.c. to 1 500 Vd.c. and removal of the limitation of 100 kVA system
size. Hence the removal of the word “small” in the title and related references in this
technical specification.
This technical specification shall be used in conjunction with the other documents of the
IEC 62257 series.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
82/942/DTS 82/979/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62257 series, published under the general title Recommendations
for renewable energy and hybrid systems for rural electrification, can be found on the IEC
website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publicatio
...