Quality Standards for Solar Home Systems (SHS)

This overview on standards is an extract of the publication: GTZ, Division 44, Environmental Management, Water, Energy, Transport: Quality Standards for Solar Home Systems and Rural Health Power Supply. Photovoltaic Systems in Developing Countries, February 2000.

IEC Draft Standard for Small-Scale PV Systems

In June 1997, the Technical Committee TC 82 WG 3 of IEC drafted its first standard with the title "PV Stand-Alone Systems - Design Qualification and Type Approval". This draft refers to individual home application with a solar generator with a maximum of 1000 Wpeak and electrical loads like lamps, radio, TV, refrigerator and telecommunication facilities. In this draft test procedures are described that can be used to determine the electrical and technical operating characteristics of PV systems and their components.

The current draft, however, is more or less a loose collection of individual documents, and is by far not yet complete for an international standard. Important information such as minimum requirements, system layout, installation, etc., are still missing or are extremely incomplete. In the meantime, there are indications that this draft will be replaced by a new proposal of a European group of experts with representatives of the French GENEC, the Spanish CIAMAT, the German TÜV-Rheinland and the European joint research institute ISPRA.

The Global Approval Program for Photovoltaics (PV GAP)

In the interest of world-wide quality assurance and as a reaction to the lack of standards up to now, various PV producers, lending institutions (e.g. the World Bank) and governmental as well as private organisations came out in favour of a world-wide programme for quality assurance of small-scale PV systems. At the 14th PV Conference in Barcelona, Spain in July 1997, the "Global Approval Program for PV (PV GAP)" was launched. The founding members established the following mission as the goal of PV GAP:

PV GAP is a global, PV industry-driven organisation that strives to promote and maintain a set of quality standards and certification procedures for the performance of PV products and systems, to ensure high quality, reliability and durability.

PV GAP is domiciled at the Central Office of the IEC in Geneva, Switzerland, and works closely together with the IEC and its suborganisation, IEC’s Quality Assessment System for Electronic Components (IECQ). Existing IEC standards for quality approval and certification of components and systems are the basis of its work, and progress is being made on the development of new standards that are still lacking. As long as there are no binding standards for certain components, recommendations are made (Recommended Standards) for the interim, which are generally based on national or regional standards.

Furthermore, test laboratories are identified world-wide, also in the developing countries, which can carry out the type tests on the components described in the standards, reliably and reproducibly.

A Reference Manual was put together, which came out in the first edition in January 1998, and can be purchased from PV GAP for 175 US$. The manual first describes in detail the ideas, the organisation and the planned procedures for a quality assurance of PV components in the framework of PV GAP. The technical part essentially consists of a list of standards that may be relevant for PV components. A comprehensive training manual entitled "Quality Management in Photovoltaics" was published in August 1999 which contains specific quality assurance standards for PV components as well as an updated list of relevant IEC standards. It also comprises proposed standards that are currently in progress (IEC TC 82 Work in Progress). ³

Moreover, a quality seal of approval is given for PV components that were tested under PV GAP conditions. This quality seal of approval is to become established if at all possible in international tenders as the prerequisite for the approval of components and systems. Qualified and recognised producers, sales and installation companies or system integrators have the right to display the quality seal of approval for PV components and systems.

The organisational structure of PV GAP provides for the following working groups:

Organization Working Group: To develop a permanent legal entity for PV GAP and a "Seal of Quality." This group will develop a PV GAP organizational structure. This group will work on an interface with the Switzerland-based International Electrotechnical Commission Quality Assurance Program (IECQ), along with the criteria for awarding the "GAP Seal."

Standardization Working Group: PV GAP will not write standards, but will accept and promote globally the IEC standards. If no IEC standard is available, then, based on peer review, PV GAP will accept existing or future standards of other bodies as "GAP Temporary Standards (GAP TS)," and promote their use globally. These GAP TS will then be submitted to IEC TC 82 to develop them into permanent IEC standards, which, when completed, will replace the GAP TS.

Handbook Working Group: A PV GAP Handbook will be established, combining inputs from the many other organizations that already have developed a handbook or parts thereof. This PV GAP Handbook then will be promoted globally. The Handbook will incorporate all of the PV GAP-approved standards.

Testing Laboratories Working Group: This group will establish criteria and compile a list of testing laboratories to be qualified to test PV components and systems according to IEC and PV GAP Temporary Standards. Reciprocity of test results from PV GAP-qualified Testing Laboratories will be established.

PV GAP Membership: PV-related industrial and commercial organisations, their representatives, producers, system suppliers, traders/retailers, installation companies as well as supporting organisations and individuals can become members of PV GAP. They must abide by the principles of PV GAP, especially in regard to the established quality standards. The advantages of membership are primarily the better marketing of products that have the PV GAP quality seal. As far as governmental and internationally financed projects are concerned, especially in development co-operation, preference will in all likelihood be given to the use of products that meet the PV GAP specifications. Moreover, members benefit from diverse information services and discounts on purchases of IEC and PV GAP publications and standards as well as the PV Reference Manual.

Sponsors and Partnerships of PV GAP (as at 10/98): Chairman: Dr. P. Varadi, P/V Enterprises, USA Secretary: Mr. R. Kay (acting) - IECQ - Switzerland Treasurer: Mr. M. Real - Alpha Real - Switzerland

Organisations represented on the PV GAP Executive Board:

Board Members: JEMA – Japan; EPIA – Belgium; NREL – USA; SEIA – USA; Newcastle Photovoltaic Applications Centre – UK; UNDP – USA; JRC, Ispra – Italy; JQAO – Japan.

Advisory Board Members: PowerMark – USA; WIP – Germany; Fraunhofer Institute – Germany; NOVEM - The Netherlands; EDF – France; ISPMA – India; National Technical University, Athens – Greece.

It remains to be seen how PV GAP develops in the future and whether offices issuing tenders and international donor organisations refer to the quality standards made by PV GAP. As the example of the Training Manual prepared for the World Bank in 1999 shows, however, the PV GAP’s quality assurance function has already met with international interest. If these standards become established in future tender procedures, tests according to PV GAP standards will be binding on the suppliers.

³ A list of IEC standards recommended by PV GAP, Work Proposals and recommended standards is provided in Annex 4. (To read the Annex of the publication download the whole text.)

The Universal Technical Standard for Solar Home Systems

The Instituto de Energía Solar at the University of Madrid has drawn up a proposal for SHS systems in co-operation with the Joint Research Centre, Ispra, the German WIPConsult and LTV-Genec within the framework of the European THERMIE-B research programme (SUP-995-96).

On the basis of 15 different documents, tenders, specifications, project reports, test requirements, etc., a set of criteria was developed for all SHS components as well as for the SHS system as a whole. Corresponding explanations that are plausible and easy to understand are provided on all of the specifications. The proposal for a new layout and sizing approach, however, does not seem very practicable.

Some of the formulations of specifications in this document have been taken over from the World Bank tenders for Sri Lanka and Indonesia.

Various PV experts commented on the draft of this standardisation proposal (it does not make any claim to being an international standard), which was distributed in June 1997, and the suggested revisions were incorporated in the final version which was released in Spring 1998. A detailed commentary by the author in behalf of GTZ on the draft study was sent to the Instituto de Energía Solar in early November 1997 and the revisions suggested in the commentary were largely taken into account in the final version. The current, revised version of this GTZ publication now contains the proposed specifications, if they did not conflict with statements from other sources or the opinion of the author.

CENELEC Draft Standards: Test Procedures for Charge Regulators and Lighting Systems in Solar Home Systems

The TÜV-Rheinland, the Fraunhofer Institut für Solare Energiesysteme and the Energy Technology Laboratory of BBPT in Indonesia have elaborated two detailed proposals for standards for charge regulators and lamps (with electronic ballasts) which have been brought into the CENELEC and IEC working groups and are currently under discussion. A panel of experts with representatives of the French GENEC, the Spanish CIAMAT, the German TÜV-Rheinland and the European joint research centre in ISPRA (Italy) is pursuing further work on these draft standards and is also commissioned to develop test procedures for both laboratory and field tests on the other system components and on the SHS system as a whole. These drafts are to be completed by the end of the year 2000 if at all possible.

In the draft standards for charge regulators and lighting systems, minimum requirements and test procedures for type tests of these two components are outlined in detail and subdivided into Part 1: Safety Tests, Part 2: EMC Tests and Part 3: Performance Tests. The revised criteria (as of 07/98) have been included in the specifications in Chapter 5 over other specifications, since it can be assumed that these draft standards are essentially accepted by the standardisation institutions (IEC, EN and DIN). Three further draft standards of this CENELEC group (PV modules, batteries and Solar Home Systems) are still in the early draft stage and still have to be properly completed and elaborated. They were incorporated in chapter 5 as a supplement to the more detailed specifications from other sources.

Initial concerns that these comprehensive type tests (a total of 30 individual tests and 13 function tests for charge regulators) could be too high of a cost factor for most producers of an electronic device in the price range of 40 to 100 Euro have been put to rest in the meantime by statements of various experts and representatives of the producers. After consulting with PV companies at an information event of GTZ and DFS, in early December 1997, most of them seem prepared to meet the high quality standards and to allow their products to be tested accordingly.

In the opinion of a leading producer of charge regulators, the high quality standards are justified, because these units have to operate reliably under the widest variety of climatic, environmental and application conditions world-wide. Comprehensive climate tests, for example, are indispensable and the widest variety of tests on electromagnetic compatibility (EMC) do not just prevent the device's interference with radio reception but also enhance the operating safety in the event of outside disturbances like surge voltages from lightning, for example.

Aside from the costs for the tests, which necessarily have to be taken into account in the product price, the process has nothing but advantages for the users, because the operating safety of the whole system is improved. Fears that only a small number of highly qualified and best-equipped laboratories in industrialised countries will be able to carry out these tests should be dispelled by qualifying and accrediting smaller laboratories in developing countries, for example in the framework of PV GAP. The world-wide networking should make it possible for every producer to have his products tested and certified in any accredited laboratory anywhere on the world.

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