JWG 1 - TC 82/JWG 1

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.

IEC TS 62257-7-2:2022 applies to all small wind turbines (SWTs) with a swept area smaller than or equal to 200 m2, and designed for supplying electrical power to isolated sites used in systems as described in IEC TS 62257-2.
This document is not an exhaustive resource for the design, installation, operation or maintenance of small wind turbines and wind power systems, but is more focused on recommendations to provide strategies on selection and criteria which may affect the use of a small wind power system (SWPS) in a rural electrification project.
The aim of this document is to provide users with the appropriate levels of reliability and safety of the equipment during its estimated service lifespan.

IEC TS 62257-9-8:2020 provides baseline requirements for quality, durability and truth in advertising to protect consumers of off-grid renewable energy products. Evaluation of these requirements is based on tests described in IEC TS 62257-9-5. This document can be used alone or in conjunction with other international standards that address the safety and durability of components of off-grid renewable energy products.

IEC TS 62257-12-1:2020 is available as IEC TS 62257-12-1:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC TS 62257-12-1:2020 establishes the framework for creating a product specification for lamps and lighting appliances to serve as the basis for evaluating quality for a particular context. Product specifications include minimum requirements for quality standards, warranty requirements, and/or performance criteria. Products are compared to specifications based on test results and other information about the product. The product specification framework is flexible and can accommodate the goals of diverse organizations and institutions. This third edition cancels and replaces the second edition published in 2015. This edition includes the following significant technical changes with respect to the previous edition.
- Annex A and Annex B were combined into a single Annex A to eliminate duplicate tables and simplify the document.

IEC TS 62257-9-7:2019 specifies the criteria for selecting and sizing inverters suitable for different off-grid applications integrating solar as an energy source.
As well as off-grid system, this document can also apply to inverters where a utility grid connection is available as a backup for charging batteries, but it is not intended to cover applications in which inverters synchronize and inject energy back into a utility grid, even though this capability may incidentally be a part of the functionality of the inverters. Single and multi-phase applications are included.

IEC TS 62257-9-6:2019 is available as IEC TS 62257-9-6:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62257-9-6:2019 proposes a simple selection procedure and cheap, comparative tests which can be performed in laboratories of developing countries, in order to identify the most suitable model of small Photovoltaic Individual Electrification Systems (PV- IES) up to 500 Wp for a particular rural electrification project from a number of products submitted for test. The tests provided in IEC TS 62257-9-6 allow assessment of the performance of a PV-IES according to the requirement of the general specification of the project (see IEC/TS 62257-2) and to verify their ability to provide the required service. This second edition of IEC TS 62257-9-6 cancels and replaces the first edition published in 2008. The main technical changes with respect to the previous edition are as follows:
- Removal of the term "small" from the title of the publication and from description of rural electrification systems.
- Removal of the limits on system voltage and power; these recommendations apply to systems of all sizes.

IEC TS 62257-7-4:2019(E), which is a technical specification, specifies the design and implementation of hybrid off-grid solar systems, where solar energy provides energy to a load in conjunction with other sources of energy. Such systems may or may not include an energy storage system. There are a variety of different system architectures and applications, and many ways in which these energy sources can be combined. This document distinguishes between different sorts of hybrid system applications and gives guidance on the design and integration of these systems.
It applies to single-phase and three-phase applications, and it covers situations where grid is available as an additional source of power for charging batteries and maintaining system reliability, but this document does not cover situations in which energy is fed back into a utility grid, although such systems may incidentally possess this function.

IEC TS 62257-9-5:2018 is available as IEC TS 62257-9-5:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC TS 62257-9-5:2018 applies to stand-alone renewable energy products. This document deals essentially with off-grid renewable energy products with batteries and solar modules with DC system voltages not exceeding 35 V and peak power ratings not exceeding 350 W. The tests contained herein are capable in many cases of adequately assessing systems at higher voltages and/or power ratings. This new edition includes the following significant technical changes with respect to the previous edition:
- replaced the term "stand-alone lighting kits" with "stand-alone renewable energy products" throughout the document (including the title) to reflect that the revised document is applicable to a broader range of products with a more diverse set of capabilities.
- added test methods for flooded lead-acid batteries.
- significantly revised the protection tests, assessment of DC ports, appliance tests, and energy service calculations based on field experience.
- revised the voltage operating points at which testing is carried out to better reflect actual operation and to simplify the procedures for testing products without lights.
- revised the energy service calculations to include the effect of multiple simultaneously connected loads on the port voltage and battery-to-port efficiency and to accommodate products with grid or electromechanical charging.

IEC TS 62257-7-3:2018(E) specifies the general requirements for the selection, sizing, erection and operation of generator sets in decentralized rural electrification systems. It applies to all low voltage combustion engine electricity generator sets energized by renewable energy such as biomass gasifier or biogas, or fossil fuel such as gasoline or diesel fuel, and designed for supplying electrical power to isolated sites used in systems as described in IEC TS 62257-2. The aim of this document is to provide users with the appropriate guide to select generator sets for using in micropower plant with different configurations and levels of reliability and safety of the equipment during its estimated service lifespan. This document describes the minimum requirement of generator set functionality and safety requirements and does not claim to be an exhaustive instruction manual or design specification.
The main technical changes of this new edition with regard to the previous edition are as follows:
- Increased the voltage and power levels to which this TS applies.
- Added descriptions of four different types of micropower systems and their relevant requirements.

IEC TS 62257-8-1:2018(E) proposes simple, cheap, comparative tests in order to discriminate easily, in a panel of automotive flooded lead-acid batteries, the most acceptable model for PV individual electrification systems. It could be particularly useful for project implementers to test in laboratories of developing countries, the capability of locally made car or truck batteries to be used for their project. The tests provided in this document allow assessment of the batteries' performances according to the general specification of the project (see IEC TS 62257-2) and batteries associated with their battery management system (BMS) in a short time and with common technical means. They can be performed locally, as close as possible to the operating conditions of the real site. The document provides also regulations and installation conditions to be complied with in order to ensure the life and proper operation of the installations as well as the safety of people living in proximity to the installation. This new edition includes the following significant technical change with respect to the previous edition: increase of the applicable voltage levels and removal of the 100 kW power limit.

IEC TS 62257-7:2017 is also available as IEC TS 62257-7:2017 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC TS 62257-7:2017 specifies the general requirements for the generators in decentralized rural electrification systems. This document is a general introduction followed by more specific documents dedicated to the generation technologies which are the most currently used in rural electrification projects. This new edition includes the following significant technical changes with respect to the previous edition: removed the word "small" from the description of the PV systems, and removed the power limit (100 kVA); increased the relevant voltage levels to 1 000 V (AC) and 1 500 V (DC).

IEC TS 62257-9-3:2016(E) specifies the general requirements for the design and the implementation of the interface equipment within the user's installation which connects to a microgrid or the generating part of a standalone system. It applies to simplified user's interfaces (distribution board) in electrical installations with maximum power of 500 VA in decentralized rural electrification systems. The main technical changes with regard to the previous edition are as follows: changing the voltage range covered by the technical specification to AC nominal voltage below 1 000 V and DC nominal voltage below 1 500 V.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-9-1:2016(E) provides general requirements for the design, erection and operation of micropower plants and general requirements to ensure the safety of persons and property. The micropower plants covered by this specification are low-voltage a.c., three-phase or single-phase, with rated capacity less than, or equal to, 100 kVA. The main technical changes with regard to the previous edition are as follows: changing the voltage range covered by the technical specification to AC nominal voltage below 1 000 V and DC nominal voltage below 1 500 V.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-9-4:2016(E) specifies the general requirements for the design and the implementation of a user's installation. It applies to single phase user's electrical installations with maximum power of 500 VA, in decentralized rural electrification systems. It is applicable to installations supplied by an AC microgrid and to installations encompassing their own single-unit AC micropower plant or DC micropower plant. The main technical changes with regard to the previous edition are as follows: changing the voltage range covered by the technical specification to AC nominal voltage below 1 000 V and DC nominal voltage below 1 500 V.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-9-2:2016(E) specifies microgrids made of overhead lines because of technical and economical reasons in the context of decentralized rural electrification. The microgrids covered by this part of IEC 62257 are low voltage AC, three-phase or single-phase, with rated capacity less than or equal to 100 kVA. They are powered by a single micropower plant. The main technical changes with regard to the previous edition are as follows: changing the voltage range covered by the technical specification to AC nominal voltage below 1 000 V and DC nominal voltage below 1 500 V.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-5:2015(E) specifies the general requirements for the protection of persons and equipment against electrical hazards to be applied in decentralised rural electrification systems. Requirements dealing with protection against electric shock are based on basic rules from IEC 61140 and IEC 60364. Decentralized Rural Electrification Systems are designed to supply electric power for sites which are not connected to a large interconnected system, or a national grid, in order to meet basic needs. Examples of such sites: isolated dwellings, village houses, community services, economic activities, etc. The main technical changes with regard to the previous edition are as follows:
- redefine the maximum AC voltage from 500 V to 1 000 V, the maximum DC voltage from 750 V to 1 500 V;
- removal of the limitation of 100 kVA system size.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-6:2015(E) describes the various rules to be applied for acceptance, operation, maintenance and replacement of decentralized rural electrification systems which are designed to supply electric power for sites which are not connected to a large interconnected system, or a national grid, in order to meet basic needs. This technical specification proposes a methodology to achieve the best technical and economic conditions for acceptance, operation, maintenance and replacement of equipment and complete system life cycle. The main technical changes with regard to the previous edition are as follows:
- redefine the maximum AC voltage from 500 V to 1 000 V, the maximum DC voltage from 750 V to 1 500 V;
- removal of the limitation of 100 kVA system size.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-4:2015(E) provides a method for describing the results to be achieved by the electrification system independently of the technical solutions that could be implemented. The purpose is to provide a method to assist project contractors and project developers to select and design the electrification system for isolated sites while matching the identified needs, such as those described in IEC TS 62257-2. The main technical changes with regard to the previous edition are as follows:
- redefine the maximum AC voltage from 500 V to 1 000 V, the maximum DC voltage from 750 V to 1 500 V;
- removal of the limitation of 100 kVA system size.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-2:2015(E) proposes a methodological approach for the setting up and carrying out of socio-economic studies as part of the framework of decentralized rural electrification projects. It is addressed to project teams and in particular to experts in charge of socio-economic studies in international projects. This technical specification also provides some structures as technical solutions that could be recommended, depending on the qualitative and quantitative energy demands, consistent with the needs and financial situation of the customers. The main technical changes with regard to the previous edition are as follows:
- redefine the maximum AC voltage from 500 V to 1 000 V, the maximum DC voltage from 750 V to 1 500 V;
- removal of the limitation of 100 kVA system size.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-3:2015(E) provides information on the responsibilities involved in the implementation of rural power systems. More particularly it covers:
- contractual relationships to be built between the different participants to a project;
- the relevant tests to be applied to renewable energy and hybrid electrification systems;
- quality assurance principles to be implemented;
- requirements for recycling and protection of the environment. The main technical changes with regard to the previous edition are as follows:
- redefine the maximum AC voltage from 500 V to 1 000 V, the maximum DC voltage from 750 V to 1 500 V;
- removal of the limitation of 100 kVA system size.
This publication is to be read in conjunction with IEC 62257 series.

IEC TS 62257-12-1:2015(E) applies to lamps and lighting appliances for off-grid electricity systems with the following characteristics:
- The power supply is AC or DC:
- AC nominal voltages up to 250 V;
- DC nominal voltages up to 48 V. The light source is CFL, linear fluorescent, or LED. Operation of the lamp or lighting appliance does not require any components to be supplied by the testing laboratory other than lampholders, wire, connectors, and a power supply. The lamp or lighting appliance does not include a battery or energy source (for example, a photovoltaic module or electromechanical generator). This new edition includes the following significant technical changes with respect to the previous edition: Overall, the narrow focus on the needs of bulk procurement programmes has been shifted to a wider framework for structuring quality assurance using appropriate methods for a range of stakeholders including governments, manufacturers, buyers, and others. The scope has been expanded from self-ballasted compact fluorescent lamps to include DC products and lighting appliances with LED, compact fluorescent, or linear fluorescent light sources.
This publication is to be read in conjunction with IEC 62257 series.

IEC/TS 62257-1:2013 introduces a methodology for implementing rural electrification using small 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 only difference being the level of quality of service and the needed quantity of energy that the customer can afford. The main changes with respect to the previous edition are as follows:
- addition of a map and an up to date list of the current IEC 62257 series and a guide "how to use the IEC 62257 series" in order to implement a rural electrification project or a stand-alone hybrid system for a remote place in a developed country;
- addition of a list of all the terms and definitions used in the series.
This publication is to be read in conjunction with the IEC 62257 series.

IEC/TS 62257-9-5:2013(E) applies to stand-alone rechargeable electric lighting appliances or kits that can be installed by a typical user without employing a technician. This technical specification presents a quality assurance framework that includes product specifications (a framework for interpreting test results), test methods, and standardized specifications sheets (templates for communicating test results). The intended users of this technical specification are:
- market support programmes;
- manufacturers and distributors;
- bulk procurement programmes;
- trade regulators. The main changes with respect to the first edition are:
- overall, shifted from narrow focus on the needs of bulk procurement programmes to a wider framework for structuring quality assurance using appropriate methods for a range of stakeholders including governments, manufacturers, buyers, and others;
- revised structure of document with modular methods (located in annexes) that are applied using four distinct test regimes;
- added a framework for categorizing products based on the arrangement of components.
This publication is to be read in conjunction with IEC/TS 62257-1:2003, IEC 62257-2:2004, IEC 62257-3:2004, IEC 62257-4:2005, IEC 62257-5:2005 and IEC 62257-6:2005

IEC/TS 62257-7-1:2010(E) specifies the general requirements for the design and the safety of generators used in decentralized rural electrification systems. Provides requirements for ELV and LV PV arrays. Particular attention must be paid to voltage level, as this is important for safety reasons and has an influence on protective measures and on the skill and ability level of operators. The main technical changes with regard to the previous edition are the following:
- this new version is focused on small PV generators up to 100 kWp;
- it provides case studies.

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.