Reliability of PV stand-alone systems for rural electrification

Transcription

1 April 2004 Reliability of PV stand-alone systems for rural electrification Tackling the Quality in Solar Rural Electrification Target Action-C Contract No. NNE5/2002/98 Work Package 1 Part 1: Literature Findings Frans Nieuwenhout Taric de Villers Nitant Mate Miguel Egido Aguilera UNIVERSIDAD POLITECNICA DE MADRID ENERGY RESEARCH CENTRE OF THE NETHERLANDS INNOVATION ENERGIE DEVELOPPEMENT ITPOWER INDIA

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3 Abstract In this first report of the TaQSolRE project, an analysis of the current status of solar rural electrification in developing countries is presented, focussing on quality aspects. It is based almost exclusively on an extensive literature review. At the end of 2003, an estimated 3.4 million households benefit from solar rural electrification, of which 2.4 million through solar home systems. Combining survey results from different sources, it was found that 63% of the installed solar home systems are still working well, and 15% is not working at all. An overview is presented of field findings regarding the different technical- and non-technical problems causing these early failures of solar systems. Quality assurance activities have been implemented to a certain extent in a number of countries. But their impact on actual quality levels still remain under discussion. 3

4 CONTENTS LIST OF TABLES 6 1. QUALITY ASPECTS IN SOLAR RURAL ELECTRIFICATION MARKETS Introduction Definition of quality Quality aspects in rural electrification National quality assurance schemes Instruments to improve quality Quality issues Perception of required quality levels in the end-user demand driven market Implementation of standards Effectiveness of standards Warranties The role of standards in extending product lifetime SIZE OF THE SOLAR RURAL ELECTRIFICATION MARKET Solar home systems Solar lanterns PV battery charging stations PV minigrids Discussion CLASSIFICATION OF RURAL PV-MARKETS Institutional aspects of the supply chain Product selection through public bidding versus end user choice Conclusions and recommendations DATA BASE ON RELIABILITY OF PV-COMPONENTS AND SYSTEMS Objectives of the data base Scope of the data base Specification of required data Operating status Reliability and dependability System performance User satisfaction Data base structure RELIABILITY OF PV-COMPONENTS AND SYSTEMS Operating status of solar home systems Reliability of components Reliability of PV modules Battery charge regulators Batteries Fluorescent lights Wiring and sockets Solar lanterns Solar battery charging systems Satisfaction of users IDENTIFICATION OF KEY STAKEHOLDERS INTEREST IN QA Introduction Definition of PV Supply and Service Chain Definition of stakeholders Definition of Quality Issues Participative pre-survey method 43 4

5 6.6 Identification of interest in QA for different stakeholders Users of solar systems Private operators Public institutions Funding sector REFERENCES 52 5

6 LIST OF TABLES Table 2.1 Number of distributed solar lanterns per country according to different sources.19 Table 2.2 Solar battery charging stations in selected countries Table 2.3 Number of installed solar home systems per country and estimate of the total number distributed in developing countries Table 2.4 Estimated total size of the solar rural electrification market for domestic purposes in developing countries [in million of households reached] Table 3.1 Major characteristics and differences between projects and fully commercial distribution Table 3.2 Quality aspects in solar product selection for two cases: selection through a bidding process with quality standards, and through en user choice only Table 5.1 Overview of status of solar home systems from 19 different sources (numbers are percentages of investigated systems) Table 5.2 Percentages of solar home systems that are working well, working partially or not working at all for projects compared to retail sales Table 5.3 Failure rates of BOS components in Nusa Tenggara province in Indonesia in Table 5.4 Failure rates of PV modules Table 5.5 Breakdown frequencies of charge regulators in early programme stage in Tunesia Table 5.6 Failure rates of battery charge regulators in % (with N the number of surveys with relevant information) Table 5.7 Battery lifetimes in the Sukatani demonstration project in Indonesia Table 5.8 Average battery lifetime in months from different sources Table 5.9 Typical average battery lifetimes in years for different battery types and different circumstances Table 5.10 Fluorescent lights: failure rates of fluorescent tubes and ballasts Table 5.11 User satisfaction in % of respondents (with N the number of surveys)

7 1. QUALITY ASPECTS IN SOLAR RURAL ELECTRIFICATION MARKETS 1.1 Introduction Solar PV systems can provide electricity reliably over many years, meeting electricity demands of households in remote rural areas. But generally, the picture looks less bright. Project evaluations show that a considerable number of these systems are not working anymore or only meet part of the design load. Technical failures often lead to high cost for users, disappointment with the solar energy solution and can result in strong negative publicity for solar rural electrification. Occurrence of minor technical problems, which still allow some level of electricity use, is often a reason for stopping credit instalments. Preventing avoidable technical problems is therefore one of the main driving forces behind activities to enhance quality in solar rural electrification. In this first report of the TaQSolRE project, an analysis of the status of solar rural electrification in developing countries is presented, focussing on quality aspects. The aim of this project is to enhance the technical quality of PV stand-alone systems by means of quality assurance procedures and the diffusion of best practices. The sometimes inferior technical quality of PV stand-alone systems hampers the confidence and acceptance by the consumers. The project tackles this issue with the help of a combined strategy - on the one hand, by promoting the quality control of PV systems according to standards that can be verified at local level and on the other hand, through development of reliability analysis software for PV installations. The methodology to reach both the targets is inherent in the critical significance of the local aspects and the need for improved feedback from field experience. Two of the scientific objectives of the project that will be dealt with in this report are: A. To identify the technical problems linked with the social acceptance of solar rural electrification in developing countries; B. To establish technical parameters that permits on a temporal basis the quantification of PV system reliability and confidence ensuring energy delivery. Work package 1 of the TaQSolRE project is called: Analysis and evaluation of solar rural electrification markets. Reporting is split into two parts. The current report consists of an analysis of quality aspects in solar rural electrification markets almost exclusively based on a literature survey. The second part of the work package 1 report will focus on findings of the field work done by the project partners. It is due at the end of the project, January This report is a follow-up activity of three previous activities of the TaQSolRE project partners, namely the Universal Technical Standard for Solar Home Systems [IES-UPM et al, 1998], the report: Issues of Quality Control of the JOULE III-funded CESIS-PV project [IED, 2001], and a review study of experiences with solar home systems [Nieuwenhout et al, 1999, 2000]. The CESIS-PV report provides an overview of the status of quality assurance procedures for solar applications in developing countries. This TaQSolRE report intends, among others, to provide an update on quality assurance status with experiences from more countries. In the CESIS-PV report, nine different PV rural electrification products were covered, with a focus on solar pumping. In the TaQSolRE report we cover quality issues with solar home systems in detail because they have become by far the largest part of the solar rural electrification market. Two other products are discussed in less detail: solar lanterns and solar battery charging stations. Quality assurance issues for these two products are expected to be more or less similar than for PV systems. In the overview of the solar rural electrification market there is a short section on PV (hybrid) mini-grids because they provide a more or less similar service level as solar home 7

8 systems. However, quality issues in PV-mini grids are not discussed. Some of the quality issues will be different and be more in line with conventional quality procedures in utility-based grid extension activities. The report is divided into six chapters. The size of the solar rural electrification market is discussed chapter 2, and the market structure in chapter 3. A database has been developed for easy access to quantitative information on reliability aspects of solar systems and components from different sources. Chapter 4 provides an overview of the structure of the database and chapter 5 summarises the main findings from the database. In chapter 6, the interests of different stakeholders in quality assurance is discussed. The first chapter continues with defining the scope of quality issues for this report, providing an outline of the different quality assurance instruments and summarising the experiences with national quality assurance programmes. 1.2 Definition of quality In general, the term quality refers to how good something is compared to a standard or compared to other products. From a technical point of view, product quality is achieved when certain product requirements are met. Quality can also be defined from a usage perspective as the extent to which a product or service meets user s expectations. The main technical aspects of quality are service lifetime of the system and its components, performance (e.g. efficiency), safety, and reliability. From the social point of view, quality in solar rural electrification can be defined as the effectiveness and efficiency of PV in achieving general development objectives and more specifically rural electrification targets Quality aspects in rural electrification A) Information Dissatisfaction with the performance of a solar system can be caused by unrealistic expectations of the users. It is not uncommon to compare it with grid electricity that usually has less capacity restrictions, often at subsidised rates. Especially in undeveloped markets, awareness about the limitations of PV is crucial. In South Africa fly-by night operators were active that sold car batteries with a 10W panel and an inverter to run an AC television. This would work for one or two days until the battery was flat. The small panel was not sufficient to meet the expected demand (see also box on user expectations). Another relevant factor is the difficulty for a buyer to obtain reliable information on the actual quality of the product. The lowest cost product involves the least amount of risk. This factor can be influenced by providing information of comparative tests or via the use of a quality seal. User expectations and information quality A real life example of a new housing development in one of the middle class suburbs of Nairobi - all houses are un-electrified and will remain so for the next few years. This was thought to be a great market for systems of Wp with 5-7 lights per Solar Home System. Sundaya Solar did a serious campaign in the area with even special offers. The result was that indeed a few households came out and had a proper system installed. But even more people that apparently were convinced about the benefits of PV went to town and purchased an A-Si module of Wp with 4-5 lights connected. But soon, they were regretting their choice, as the cheap module did not live up to their expectations. [de Bakker, 2003] 8

9 There is a widespread practice of providing an estimated amount of electricity from a solar home system by multiplying the nameplate Wp power by the equivalent number of peak sun hours (typically around 5 hours in tropical regions). This figure is then used to calculate how many hours the lights or the television can operate. But this does not take into account all sorts of losses, which typically reduces the available energy by about 50% [Nieuwenhout et al, 2002]. Household surveys in Indonesia showed that many users were not aware about their rights and obligations in government sponsored projects. People tried to sell their system while it was still government property for a ten-year lease period. Not everyone knew their rights of obtaining replacement for components under warranty [unpublished SHS monitoring results BPPT and ECN in Indonesia, 2003]. According to a survey in Chile 95% of the SHS users did not know where to obtain replacement parts. [Cancino et al, 2001] On the other hand, the initial TaQSolRE survey in India indicates that the user is more casual and callous about replacement of system components, especially when major price of the system is paid through government subsidy programs. B) Project design Many projects have failed due to poor follow-up and lack of capacity building. The ESD study: PV market chains in East Africa provided the following example from Ethiopia: In 1996, over two thousand PV-powered radio receivers were sold to primary schools as part of a distance education program. The systems were well installed by Addis based suppliers, and all the aspects of the initial project were carried out well. However, at the planning stage, no consideration was made of the long-term maintenance and parts replacement for the systems installed, namely batteries. By the year 2000, virtually all the batteries in these systems had failed, and the schools were not using the otherwise intact equipment. They did not know how to replace the batteries, and they did not know which parts of the systems were not working. [ESD, 2003] C) System design In the commercial markets for small systems in Eastern Africa, there is a trend where whole system suppliers are giving way to over the counter traders of inexpensive components that are sold on a piecemeal basis. In this process the attention towards good system design is decreasing. [ESD, 2003] According to Duke et al, the most common design problems they found in a survey of the commercial market in Kenya are: PV panels are undersized relative to the loads, and batteries are oversized relative to panels Between 70-90% of the design decisions are made by vendors and customers only, without input of a technician. Only 7% of the shops that sell PV specialise in PV. Even among solar technicians design knowledge is limited. Only 17% were able to correctly size a battery for a solar home system. [Duke et al, 2002] In solar home systems that are only used for lighting it is common to find more than half of the electricity being used when people are asleep (see e.g. the profile of use shown in figure 12 in [Parodi et al, 2000]. For orientation lighting, including one or two small 1 W incandescent lights can potentially save almost half of the investment cost [Nieuwenhout et al, 2002]. D) Component quality In PV rural electrification, there is a substantial number of faulty installations, in spite of the generalised idea of success yielded on the scientific project meetings, which is high enough to doubt on the maturity of this energetic source. However, it is also a reality that the modules as well as the BOS components are rather technologically advanced products, and the manufacturers can produce reliable and durable equipment [Maish, 1997]. Failures on the installations are linked not to the modules, but to the BOS components and also, largely, to the 9

10 installation. The reason of the bad operation is usually the malfunction of some of the components, although it is also frequent that the failure is associated to a bad installation or maintenance and in some cases, a wrong design of the system. Quality problems on the Kenyan market are overrating of modules, poor quality amorphous silicon modules, and low quality lamps and BOS components [ESD, 2003] The lack of economic resources, together with the ignorance of technical requirements of PV systems, led to the consideration of the regulator as the more dispensable element of the installation. (In Kenya, which has an important private market, only a 10% of the systems are provided with a regulator, of which 18% are by-passed [Van der Plas, 1999]). Taking into account that the system is often purchased in parts, the acquisition of the regulator is usually postponed. The result is that the battery lifetime is shortened the mean SHS lifetime is about 1,5-2 years [Huacuz, 1995]. Considering the best case, if the cost of a PV system accumulation is supposed to be the 33% of the initial cost, we can deduce that the battery is the most expensive element in photovoltaic electrification over the system lifetime. If this value is compared to the mean values reached in professional installations of some kw peaks, the difference is huge. The battery service life on these lasts up to ten years [Spiers, 1996]. The most important application of SHS is illumination, followed by TV. Given the simplicity of the technology necessary to produce the ballasts, they are usually manufactured locally. The advantages of this are the easy access to spare parts, as well as the adaptation to the local market. However, the lack of a generalised quality control system, impacts on the heightening of the failure rate. The improvement of the photovoltaic rural electrification situation is based on the analysis and comprehension of the characteristics of all the elements building up the installation. That is the reason why the standardisation task and consequently, the development of test procedures allowing the corroboration of the pursuance of the standards, are a priority. The results of the First Regional Solar Programme (PRS1), which have been evaluated quasi unanimously very positively by the scientific community, constitute an example of how this mechanism determines the success of a project [FONDEM, 1996]. The process of standardisation and certification of the specifications pursuance is far from being innocuous. The development of highly sophisticated normative procedures, either for standards or for certifications, can turn up into a curb on the local market development, which are, however, the main beneficiaries of the rural electrification programmes. Besides, sophistication does not necessarily imply reaching the aim of the quality improvement. On the contrary, it increases the technological dependence of developing countries, which hinder the sustainability of electrification programmes. The fact is that the technical committees that decide on the international standards are mainly composed of industrialised country representatives. PV rural electrification is applied basically in developing countries, but the technology and the manufacturing of the PV system components: PV modules, charge controllers, solar or stationary batteries and loads is lead by developed countries; consequently, there is a lack of feedback of field experiences in the components design. Given these serious quality issues, the global PV industry, supported by financial institutions and government agency funding programs jointly agreed on the need for a global PV quality assurance program. The result, with the guidance of the PV industry and the PV community, was the formation of the Global Approval Program for Photovoltaics ( PV GAP) in The PV GAP approval system includes the elements of a globally acceptable quality system. It also provides the approved manufacturer with a distinctive PV Quality Mark for PV components and a seal for systems, based on IECQ approval. However, the full technical standards package for PV stand-alone systems is not yet finished. Only PV modules standards are completed, but for the B.O.S. components the process is under 10

11 way. In consequence, the PV GAP is proposing to use standard drafts not globally accepted or discussed. One of the key points on the technical success of PV rural electrification is proper maintenance; although PV systems were considered not to need it, this old idea has been rejected as a result of the experience, proving that no large-scale project can be implemented without ensuring this point. The maintenance is based on the availability of qualified technical staff, spare parts and affordable costs, as well as the necessary infrastructure to perform it. These conditions could be seriously compromised if the local PV market is not encouraged as the consequence of promoting a certification methodology in which the local actors are not being involved. From the photovoltaic material suppliers' point of view, the certification of their products by accredited laboratories can imply a notable increase on its fabrication costs. Several consequences are derived from this fact: increase of the electrification total costs, reluctance to include the certification of products as a contractual requirement, boost on the free market of non standardised products. The direct consequence is that the dissemination of photovoltaic electrification could be sharply restricted. Seven years after the PV GAP was launched, only three PV module brands have obtained the PV Quality Mark and no more than five laboratories have been accredited; none of the PV system have obtained the PV seal yet. E) Installation Projects usually arrange installation of systems through their own staff or by hiring local technicians. In retail sales markets, most systems are self-installed. Technicians rarely get a formal training. On-the-job training is more common, and likewise also more effective. Quality of the PV system depends to a large extent on the quality of the installation. Common problems are: insufficient module support, incorrect orientation and tilt of the module, shading of the module, use of too small wire sections, inappropriate fixing of wires on the walls, lack of connection boxes and twisting of wires instead of using switches. Low quality of installation leads to unnecessary losses in system functionality. F) User training When user training takes place it is usually a one-time effort, at the time of the installation, depending on the availability of the household. In a survey in Chile in a village in a dusty environment it was reported that 91% of the interviewed said that they were instructed to clean the panels. Most panels were difficult to access, and owners were often elderly people. On the other hand, even younger people did not clean their panels [Cancino et al, 2001]. This illustrates the need for follow-up activities after the initial training. G) After sales services It is seen that many PV systems fail duel to lack of an effective servicing network. The user is mostly not trained and moreover is not capable of maintaining the system. In Kenya and Uganda, efforts are being put in preparation of guidelines for, system design, installation and after sales services [ESD, 2003]. Initial TaQSolRE survey findings in India show that 5 years of after sales service is now included as part of the cost of the system. Efforts are being made to put a system in place for implementing a reliable after sales service network. Several manufacturers / installers of stand alone SPV systems in India seem to have taken up the service aspect seriously National quality assurance schemes Worldwide efforts to improve quality in solar rural electrification have focussed mainly on introduction of product standards. National standards have been formulated in a number of countries (e.g. India, Indonesia, and Morocco) where these are used to select suppliers for government projects. When each country has its own standards, this provides a barrier for international suppliers of hardware. PV-GAP is the lobbying organisation to get international standards and quality marks generally accepted. 11

12 Projects of bilateral donors often have some component that supports industry in the donor country. This usually results in the application of high-quality and high-cost components, manufactured by large internationally operating companies. Their own internal quality procedures typically result in sufficiently high product quality. Since the focus is mainly on hardware sales, the other aspects such as installation, training, etc. receive relatively less attention. Consequently, there are lots of examples of failed donor projects in solar rural electrification. Nepal One of the few positive exceptions regarding explicit emphasis on quality issues in bilateral donor funded activities is the support of the Danish government to the solar photovoltaic sector in Nepal through the Energy Sector Assistance Programme (ESAP). Possibly due to absence of a photovoltaic home industry, the Danish support provides sufficient attention to all major quality aspects and not just product quality. Active support of the Nepalese government, among others through a subsidy scheme, has led to a rapid development of the PV sector in Nepal. PVmodules and batteries are imported from various manufacturers outside Nepal. Most of the remaining Balance of System components are produced locally. At first, product quality of the locally produced components was low. But the latest charge regulator designs now meet the Nepalese Interim PV Quality Assurance (NIPQA) standards. The whole quality assurance chain in Nepal contains procedures for attaining product quality, service quality, and a management information system to keep track of quality of PV installations in the field. Installers of solar home systems and other PV equipment are only eligible for government subsidy if their products meet the Nepal Interim PV Quality Assurance standards. These will be replaced by international standards such as PV-GAP. The NIPQA document specifies minimum standards of the PV system components and installation practices. For cables and switches, the Nepal Bureau of Standards and Metrology has developed a quality seal, which is mandated in the NIPQA standards. A Solar Energy Test Station (SETS) has been established to perform tests for quality control based on the NIPQA standards. Other SETS activities are support in product development and provision of manpower training. For promoting quality in service provision in Nepal, criteria and procedures have been developed for solar PV companies to qualify for the government subsidy programmes. Through a Performance Evaluation mechanism, the Alternative Energy Promotion Centre (AEPC) evaluates the performance of participating companies. Criteria exist how to grade the different companies. Default will result in disqualification. AEPC verifies the quality of installed SHS and the after sales service through regular visits of users. The Centre for Renewable Energy (CRE) has produced training manuals for solar electric technicians. This includes skill-testing standards. After passing the tests, installers receive a certificate. Through the Energy Sector Assistance Programme, a management information and monitoring system has been developed. This system is intended to enable a close follow up on the quality of the solar PV installations in the field and will be an integral part of the overall Management and Evaluation system for solar PV systems. [SEMAN, June 2003] Monitoring of field activities is an integral part of the quality assurance chain in Nepal. For the companies to obtain the government subsidy, the new owners of the SHS have to fill out a form with which the installer can obtain the subsidy through AEPC. Based on this information AEPC organises sample visits in the field to check if the right equipment has been installed correctly and if the regular maintenance visits actually took place. If not, the installing company has to reimburse the subsidy. If there are more of these occurrences, the company will be blacklisted. 12

13 The quality of the equipment, the installation and service determines the ranking of the company (grade A, B or C) [Vreeken, 2004]. World Bank China The World Bank is active in promoting quality improvement in a number of countries, most extensively in a recent project in China. A range of quality improvement features have been applied in the World Bank/GEF-assisted China Renewable Energy Development Project: Business development assistance to improve business planning, develop warranty documents and setting up procedures for quality assurance; Development of technical product standards; Strengthening capabilities of local testing and certification institutions to support them in obtaining ISO Guide 25 status that will allow international acceptance of product certificates; PV product design improvement through training of engineers of a university group. This group is now the centre that is providing design assistance services to local manufacturers; Manufacturing quality improvement training for companies, focussing on establishment of an ISO Guide 9000 quality compliant management system; Training in installation and maintenance services; Information dissemination about qualified products and participating dealers [Cabraal, 2002]. World Bank Indonesia In the early nineties, the World Bank/ GEF assisted Renewable Energy Development (RED) project was conceived. The solar component had a target of 200,000 solar home systems. When everything was ready for the start of implementation, the financial crisis of 1997 made the provision of loans in rural areas impossible. Economic recovery in Indonesia was very slow and project design was not flexible enough to cope with these adverse circumstances. End of 2003 the project was stopped after about 7,000 solar home systems had been distributed. One of the positive outcomes of the project is the establishment of a comprehensive quality assurance infrastructure. To become eligible for support through the RED project, companies had to submit a business plan containing a description how they intend to install the systems and establish a local service infrastructure. Through the Project Management Office, companies could receive support in formulating these business plans and obtain training in business development. Technical specifications were formulated. Originally, the Staff Appraisal Report stated a minimum module capacity of 50 Wp. Modules have to meet the internationally recognised standards. Batteries were required to meet an Indonesian battery standard (SII ). Use of locally made car batteries is allowed. For the remaining BOS components standards were formulated. An existing solar energy laboratory (LSDE) was assisted to obtain official ISO Guide 25 accreditation as a certified solar component-testing laboratory. Post-installation monitoring was foreseen through random audits [World Bank, 1996] The first round of component testing was done by UL because LSDE was still preparing their testing facilities. Somewhat unexpectedly, the fluorescent lights had most problems in passing the tests. Fluorescent lights from four local manufacturers were submitted for qualification. A high quality, high-cost fluorescent light was the only one that immediately passed the UL tests. ECN was asked to assist the other three manufacturers to improve their designs. One was a simple one-transistor design that could not be improved to meet the standards. Adoption of a complete new design was the only alternative. The two others were based on the same principle. They were good quality designs, but both did not meet the efficiency requirement by a few percent. One of these designs had been in production already in Indonesia for years and more 13

14 than 100,000 units had been sold at that time. The other design was a prototype that was not yet in large-scale production. Optimising the electrical component values resulted in a slightly higher efficiency, but still just below the requirement. Only when the cheap diode would be replaced by a much more expensive varistor, the efficiency requirement could be met. Due to the absence of a substantial project demand at the time of the ECN design assistance (1998), none of the manufacturers implemented the ECN recommendations. When the RED project eventually took off, the two fluorescent lights obtained a certificate from LSDE. This illustrates the need for well defined standards that prevent sales of low quality products, but not necessarily target at achieving the highest efficiency levels [Unpublished ECN laboratory work in 1998] Some years later, ECN became involved in monitoring a follow-up activity of a large, Australian funded solar home system project in Indonesia (the AusAid project). We encountered many problems with the fluorescent light inverter, which was produced by the company of which the prototype design just did not meet the requirements in the beginning. They had discarded their original design and instead were producing a modified version of the expensive design of another company, which immediately passed the UL test before. Some electrical components were replaced by cheaper ones. One of these components has a design value that is very close to the maximum current level that can be expected in the inverter. Consequently, the failure rate due to burned inverters is substantial. At least 120,000 of these inverters have been produced for the AusAid project and local government projects [field findings monitoring visits BPPT-ECN ]. The overall impact of introducing standards for fluorescent light in solar home systems in Indonesia on the quality of fluorescent light inverters in the field has been negative. The lowquality producer stopped production before the RED project actually took off as a consequence of the financial crisis of The local producer for the government projects replaced its basically good design for a bad imitation of an expensive high quality design. The other local producer continued to produce his un-modified design, mainly for export. More then 1,000,000 have been sold at the end of 2003, which indicates that this design is meeting customer requirements. This example of a negative effect of introduction of product standards on the market in Indonesia is likely to be an un-typical case. However, it illustrates that formulation and implementation of standards does not necessarily always lead to the desired quality improvements. There is a need for sufficient flexibility that allows reacting on field findings of badly performing equipment that nonetheless have obtained an official certificate Instruments to improve quality In a fully commercial market, other instruments, besides standards and certification, are relatively more important. Some of these instruments are described in a paper by Duke et al These are product branding, warranties, domestic component testing and disclosure, certification and labelling, and minimum quality standards. Product branding Advertising and product branding primarily concern with provision of quality information. In general, companies that invest in branding must deliver high quality goods. In case of PV modules this mechanism does not work well to promote quality because users have no means to assess module performance except when degradation is very serious [Duke et al, 2002]. Warranties Ideally, warranties protect users against premature failure and under-performance of the product. For solar home systems the efficacy of warranties is limited because of difficulties in measuring module performance, lack of knowledge of user of their rights and the fact that some importers and vendors do not honour warranties [Duke et al, 2002]. 14

15 For the worst quality brand of PV-modules on the Kenyan market, the warranty terms are more or less similar compared to the best ones. However, in a survey reported by Duke et al, 2000, all the modules of this brand showed less than 75% of rated power, while 90% of these modules were still under warranty. Domestic component testing and performance disclosure In absence of minimum quality standards, testing system components can still influence product quality on the market. In an evaluation of the PV module quality in the Kenyan solar home system market, this was identified as a promising instrument by the authors [Duke et al, 2002]. There are two main differences between component testing for performance only and testing for international certification (such as IEC for thin film PV modules). First, international module certification involves not only the power rating, but a wide range of quality aspects, requiring a considerable number of tests, but at a high costs. Secondly, the certification programmes result in a binary conclusion: pass or fail, while a performance test results in the measured output figures [Duke et al 2002]. The effectiveness of this instrument is still unclear. Sales of the lowest quality a-si modules in Kenya have continued to increase from a market share of 20% in 1996 to over one-third in the first quarter of This took place, despite the fact that this low quality brand had the highest price per delivered Wp. But the price per rated Wp was similar to their competitors. Their somewhat higher rated power likely helped in marketing [Duke et al, 2002]. Certification and labelling IEC standards exist for crystalline and thin film PV modules. In 2000 only one of the brands of amorphous silicon PV modules on the market in Kenya was certified (Millennia of BP-Solarex). Certification is not expected to affect the market in Kenya very much, since buyers do not trust any seal. Low quality product vendors could easily confuse the public by misleading claims. An example is the claim by a low quality supplier that their modules have: "Quality Design to ISO 9001". This only means that their manufacturing facility commits itself to explicitly formulated management practices, but it does not say anything about the quality of the products [Duke et al, 2002]. Minimum quality standards Governments could legally prohibit import and sales of solar components that do not meet certain minimum quality standards. However, there is a fear for possible corruption, and high costs associated with establishing local testing facilities. Furthermore, minimum standards could be too strict, leading to reduced competition. [Duke et al, 2002]. The case of Kenya provides an illustration of the importance of quality issues. In Kenya, PV was left to the commercial world of private entrepreneurs. It developed into a component market where people buy components on a piecemeal basis and combine these into a system: Batteries are often second-hand, and usually grossly oversized. Controllers are rarely used (A rough estimate is that some 75 % of the solar home systems in Kenya still are not equipped with a controller), or cheap controllers are used that do only battery overcharge protection (HVD) and no under voltage load cut-off (LVD). Lamps are often of such poor quality that they need replacement in a couple of months. The result is that during a decade of free enterprise the image of PV suffered a lot and that government agencies generally do not consider PV as a credible alternative to grid-based electrification. Up to this very moment the government of Kenya has never been involved in any PV based electrification. If the performance of PV systems is indeed not drastically and worldwide improved a serious backlash might be expected [de Bakker, 2003]. Management information systems In Indonesia the first government project with a formal management information system was the AusAid project, through which 36,600 SHS have been distributed in Management 15

16 of a previous project (Banpres) by BPPT was seriously hampered by a lack of information on financial status and technical problems. To address these issues, a Management Information System was planned for the AusAid project. Computers were installed in government offices in the 14 regencies. Main objective of the MIS was to control the implementation of the monthly payments and the provision of SHS spare parts in each of the regions. Village co-operatives that were responsible for local management send hand written status reports to the regency offices, from which they were supposed to be send to Jakarta by modem. However, due to problems with the quality of the telephone lines, the MIS operators at regency level could not send their reports to BPPT in Jakarta. Consequently, the MIS was stopped in 1999 [Fitriani, 2003]. 1.3 Quality issues Perception of required quality levels in the end-user demand driven market In the commercial market, buyers focus primarily on the price. It appears that there is no interest in taking into account quality aspects. The reasons behind this seemingly irrational behaviour are complex. One important factor is that discount rates are much higher than what is common in industrialised countries due to the tightness of the availability of money (see box). Discount rates - This is an example of how high discount rates affect user choices in developing countries. When a poor farmer is asked to choose between two plastic buckets for sale; Bucket A costs 2 dollars and last for 2 months and Bucket B costs 4 dollars and last for a year. Still, many people will opt for the absolute cheapest option. Money is that tight. [de Bakker, 2003] Financial benefits of using high quality equipment will be mainly through longer component lifetimes resulting in lower future expenses and lower total expenditures over a longer period of time. However, due to high prevalent discount rates the net present value of these benefits is relatively low, making the choice for low-cost low-quality a rational decision Implementation of standards In the short term, implementation of standards results in protecting users from dangerous, inefficient and short-lived equipment that will certainly lead to disappointment with the solar energy option. In the long run, standards will influence component developers in designing better, more suitable products. Strict standards can be beneficial for the long-term objective of product quality improvement, but can have negative consequences on the short term. Due to the limitation of choice, prices for consumers will be higher than otherwise, and the price/performance ratio is possibly higher than optimal. When suppliers can not meet the requirements, this can provide an incentive for cheating. Often, local production will not be able to meet strict standards. In the case of Kenya, imports have to be evaluated by the Kenyan Bureau of Standards, whereas local producers enter the market without any certification. Small local companies that do not meet any standards are likely to have a negative impact on the image of PV in East Africa. This might weaken government support for solar rural electrification. Ideally, one would like to have standards that become gradually more strict when the industry becomes more and more mature. However, the process of getting international standards formulated and accepted is difficult and slow and does not allow for frequent adjustments of quality levels over time. International manufacturers, the World Bank, research- and testing institutes dominate the current debate about standards for solar rural electrification equipment. These stakeholders 16

17 appear to have an interest in formulating relatively strict standards. These can push local producers out of the market. Standards should preferably not be made for each individual country but should be valid globally. The main reason is that from a manufacturer's point of view the quality of products should not have to meet a different set of standards for each country. This will help to reduce manufacturing costs through economies of scale Effectiveness of standards Some cases have been reported where tested equipment showed relatively high failure rates when applied in the field. In Indonesia, one of the local suppliers of fluorescent light inverters for solar home systems have a design that was tested in the framework of the World Bank Indonesia RED project. However, many of these light inverters had to be replaced due to burnt components. It turned out that the specified maximum current for the transistors is close to the design current, resulting in many early failures [personal communication BPPT, Oct. 2003]. ECN has tested a number of batteries for solar home systems. One of these is widely applied in Indonesia. Laboratory tests showed no degradation or loss of capacity over a nine-month period. Despite the use of charge regulators, many complaints about early failures come from the field (completely dead within a few months). It appears that the manufacturer is not able to maintain a sufficiently high production quality over time. Both examples illustrate that standards are not sufficient to guarantee a high product quality and long lifetime. Testing focuses on product design. But testing outcomes also depend on the production quality of the batch of the samples that were tested. This can change over time Warranties Both in retail sales and projects, it is common that warranties are provided for the modules, the battery and the charge controller. Providing a warranty is a marketing instrument that is used to create extra confidence with the buyer. It also provides continuous incentives for manufacturers to maintain a sufficiently high production quality level. In practice there are doubts to what extent warranties are actually being honoured. Transport costs back to the manufacturer are usually very high (see box). Many users do not seem to be aware of the possibility of getting replacements. In most countries this instruments needs further strengthening before it really has a positive impact on quality. Warranty implementation In Kenya, Sundaya imports solar home system battery boxes with and without batteries included. Many companies in East Africa equip these with their own battery. On the other hand there is the box with battery included, imported from Indonesia. These imported batteries have been approved by the World Bank for their projects in Indonesia, Sri Lanka etc. The local Kenya batteries have no such approval, and are probably of somewhat lesser quality. However, if an imported battery fails within the one-year warranty period there is an instant problem. The manufacturer does warrant its batteries, but sending a single battery back to Indonesia is not a serious option. In that case it is much easier to use locally manufactured batteries instead of certified imported batteries [de Bakker, 2003] The role of standards in extending product lifetime To facilitate a sufficiently long component lifetime is one of the objectives of standards. Since expected lifetime can be a few years for batteries, and in the order of 10 years for battery charge regulators, testing for such long periods is impossible. Accelerated lifetime tests, such as e.g. thermal cycling for PV-modules, are less relevant for batteries and charge regulators. For some aspects, different standards have considerably different requirements, e.g. for the set-points of 17

18 the charge regulators. Another example concerns fluorescent lights. On theoretical grounds one expects that the crest factor 1 should be limited, as it is in most standards. However, recent work at IES shows that there is no relation between crest factor and fluorescent tube lifetime. These examples illustrate the limitations of the knowledge within the PV-community on the background behind certain lifetime determining parameters. Since not all relevant parameters determining lifetime and reliability of solar equipment are well known, overly reliance on product standards can be detrimental for overall quality. More emphasis is required on feedback of field experiences to complement the outcomes from testing laboratories. Procurement procedures need to be flexible to allow for reconsidering original qualification, whenever actual failure rates are higher than acceptable. 1 Crest factor is the ratio between peak and RMS voltage of the fluorescent lamp inverter wave-form. 18

19 2. SIZE OF THE SOLAR RURAL ELECTRIFICATION MARKET To assess the relative importance of solar PV as a rural electrification option, the total number of households in developing countries that have been reached with solar electricity has been estimated. Most of the literature is about solar home systems, resulting in a relatively reliable figure for the total number installed. Information about solar lanterns is much more difficult to obtain, and the resulting estimation is therefore much less reliable. 2.1 Solar lanterns Quantitative information on solar lantern distribution could be obtained only from three countries (see table 2.1). Through its subsidy programmes, the Indian Ministry of Nonconventional Energy Sources (MNES) has subsidised distribution of 441,000 units up to March A solar lantern manufacturer in the Netherlands estimated the Chinese market to have a cumulative size of 160,000 solar lanterns. China has a number of solar lantern producers, but most of the production is for the camping market in Europe and the USA. In Ghana at least 2,000 units have been distributed. In total 0.6 million lanterns were distributed in these three countries. On average, they have 0.26 solar lanterns distributed per 1000 inhabitants. Table 2.1 Number of distributed solar lanterns per country according to different sources Quoted Population lanterns Country Number Year in 2001 per 1000 Source ( x1000) (x1 million) population Ghana SDG 2002/2003 India MNES, 2003 China Nijland, 2003 Total Source: TaQSolRE database 2.2 PV battery charging stations In a solar battery charging station, people bring their batteries to be charged in one or more days. It resembles the common practice of having a battery charged in a nearby town with a grid connection or by someone having a genset. In some African countries surveys found that around 10% of the population in areas without electricity grid use batteries in this way. When distances to the nearest place with electricity are too large, solar battery charging stations can become an option. In practice, very few of these installations exist worldwide. Only in Thailand the government solar PV part of the rural electrification programme focuses on solar battery charging stations. About 1.9 MWp of battery charging stations have been installed in Thailand, funded through two government departments (DEDP and PWD). More than 1600 stations have been installed, averaging about one per village without grid access. In a paper about the programme in Thailand, Donna Green presents the figures as presented in table 2.2 with numbers of installed battery charging stations in selected countries [Green, 2004]. 19