Technical Standards for Solar Home Systems (SHS)

Overview

To assure the quality of a photovoltaic power system and its correct functioning and guarantee costumers' satisfaction it is important that the components of the system and the system as a whole meet certain requirements.

The GTZ prepared a publication which gives an overview of different standardisation activities and existing standards that are relevant for solar home systems (SHS) and rural health power supply systems (RHS):

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.

The following wiki page is an extract of the publication mainly regarding Solar Home Systems (SHS).

Introduction

Photovoltaic (PV) systems for applications in developing countries have been tested, optimised and disseminated throughout the world over the last 20 years. A wide variety of demands have been made of the components and systems, partly for reasons due to countryspecific characteristics or regional availability, but also because there were no binding standards, or if there were, they were often not known.

The project activities in technical and financial co-operation at bilateral and multilateral level have moved away from the pilot phase and towards the dissemination of PV systems. Yet, secure technical standards are required for dissemination in order to minimise the need for adjustments after the fact and the related costs in the case of large unit numbers.

An international survey carried out in preparation for this publication showed that several different standardisation activities are in progress. Probably the most interesting international project is the so-called "Global Approval Program for Photovoltaics (PV GAP)", but also technical specifications such as those that have been proposed by the World Bank or the University of Madrid have already been elaborated in great detail.

The publication provides an overview of standards that are relevant for Solar Home Systems (SHS) and in Rural Health Power Supply Systems (RHS). It is intended to facilitate the selection of PV systems and components, especially in tenders, and to provide the impetus for a standardisation of PV systems on a scale that is as broad as possible. Moreover, it also identifies those components for which there is still a need for technical specifications.

This should lead, in the long term or better yet in the medium term, to binding, internationally recognised technical standards, especially for the use of photovoltaic systems in developing countries.

In preparing this publication, all of the well-known national and international institutions concerned with standardisation activities in the field of photovoltaics were contacted in writing. The existing photovoltaics projects of GTZ were also included in the survey.

In the course of the survey, information and documentation obtained from the World Bank, the World Health Organization (WHO), the international standardisation institution IEC, the European standardisation institution CENELEC, the U.S. standardisation office IEEE, as well as a series of projects, firms and experts, were compiled and evaluated.

The available PV-relevant standards were evaluated and summarised in the form of a table with a breakdown by components.

The list of standard specifications for tenders for SHS and RHS forms the largest part of the publication. Eleven different documents with specifications for PV systems and their components were evaluated for this purpose and summarised in a table. These documents varied widely in terms of quality and scope; some of them were intended for the specification of individual components, others as tender documents for whole systems.

Based on these documents, standard specifications were prepared that can be used directly as text modules for international tenders. The minimum requirements were chosen in such a way that a reliably functioning Solar Home System can be set up according to the current state-of-the-art.

Systems and components that are used for power supply to rural health stations (RHS) have to meet higher standards as a matter of principle. The available experience with PV systems in this area of application to date as well as a series of documents, especially from WHO, were evaluated and condensed. A separate list of specifications was compiled for the RHS sector.

A separate set of standard texts for tenders for Photovoltaic Pumping Systems (PVP) entitled "Proposal for Tender Documents for the Procurement of Photovoltaic Pumping Systems (PVP)" is also available from GTZ, Div. 44, Sustainable Energy Systems.

Overview of Specifications for Solar Home Systems and Rural Health Power Supply

In the framework of the international survey, various documents with specifications for Solar Home Systems and their components were evaluated and summarised in the form of a table. The specifications in the table were subdivided into the following categories:

• PV generator
• Support structure
• Battery
• Charge regulator
• Lamp, ballast
• Wiring, installation
• Documentation

The following 11 documents were evaluated. Not all of the documents did include all components:

[ 1] Madrid “Universal Technical Standard for Solar Home Systems”, Instituto de Energía Solar, Universidad Politécnica de Sdrid, European Commission, Thermie B: SUP-995-96, EC-DGXVII,1998

[ 2] FHG-ISE ´94 “Ladereglertest”, Fraunhofer Institut für Solare Energiesysteme, for GTZ OE 4150, Energie und Transport, 1994

[ 3] GTZ ´93 “Standards für SHS-Laderegler” und “Vorläufige Grundanforderungen an elektronische Vorschaltgeräte”, GTZ, 1993

[ 4] PSE Tunisia “Lastenheft Laderegler und elektronische Vorschaltgeräte für Photovoltaische Kleinsysteme”, c. 1994

[ 5] Steca Midi “Datenblatt, Solarix Midi & Mini”, Steca Solarelektronik, c. 1993

[ 6] SEP Marocco “Proposition d’un standard technique pour les systémes photovoltaiques familiaux”, CDER, Morocco, 1997

[ 7] Namibia Health ”Tender: Okavango Clinics: Photovoltaic Systems”, GTZ, Department of Works, Namibia, 1997

[ 8] Namibia SHS “Tender Annex B: Specifications for Solar Home Systems (50Wp)”, GTZ, Ministry of Mines and Energy Namibia, 1997

[ 9] TÜV/CENELEC Standard Proposals: “Test Procedures for Charge Regulators and Lighting Systems in Solar Home Systems”, CENELEC CLC BTTF 86-2, 1998

[10] Philippines ‘94 “Material Specification for Solar Home Systems”, GTZ SEP Philippinen, 1994

[11] World Bank “Indonesia: Solar Home Systems Project, Specifications”, World Bank, 1996

The results of the evaluation are listed in Annex A2. There is a separate table for each component. (To view the tables downolad the whole text.)

The specifications table can be used to get an initial overview of which criteria and corresponding components are mentioned in the respective documents.

The table for charge regulators is the most comprehensive; charge regulators are included in all 11 documents. Due to the variety of requirements, local conditions, personal preferences and, last but not least, the different purposes for which the documents are used, a total of 91 criteria were identified for charge regulators, some of which complement each other, or also conflict with one another, and in many cases can be summarised into more general criteria.

At the same time, however, this variety of criteria also shows that there is an urgent need for standardisation, especially of the main components charge regulator and lamp/ballast. On the other hand, if one considers the table for PV generators, for example, one finds that many criteria are already covered by the reference “Qualified according to IEC 61215”.

Specifications for Tenders of SHS and RHS

The most up-to-date, comprehensive and best elaborated documents from the previous chapter 4 have been used as the basis for the proposed specifications of SHS and RHS.

Specifically, these are:

• the tender documents of the World Bank for 200,000 SHS in Indonesia (and similarly 30,000 SHS in Sri Lanka) [11]
• two tender documents for SHS [8] and RHS [7] in Namibia (which are partly based on the World Bank specifications)
• the proposal by the University of Madrid for a “Universal Standard” [1]
• the CENELEC draft standards for charge regulators and lamps/ballasts of the TÜVRheinland and FHG-ISE [9]

The specifications which, in the author's opinion, gave the best technical description were selected from these documents, revised and compiled according to component and topic. These can be used directly as text modules for international tenders. The minimum requirements in each case were selected in such a way that a reliably functioning system can be set up according to the technical state of the art.⁶

Tender Specifications for Solar Home Systems and Rural Health Power Supply Systems

Some of the texts proposed for the specifications presented here include additional notes marked “Optional”, “Health” and/or “Comment”:

Optional: Optional specifications for higher requirements, alternative equipment or special environmental conditions

Health: Additional or alternative specifications for Rural Health Power Supply Systems (RHS) with stricter requirements

Comment: Explanation of the reason for choosing a certain specification or a personal opinion of the author