Pico solar electric systems

Pico-solar Electric Systems This book provides a comprehensive overview of the technology behind the pico-solar revolution and offers guidance on how to test and choose quality products The book also discusses how pioneering companies and initiatives are overcoming challenges to reach scale in the marketplace, from innovative distribution strategies to reach customers in rural India and Tanzania, to product development in Cambodia, product assembly in Mozambique and the introduction of ‘pay as you go’ technology in Kenya Pico-solar is a new category of solar electric system which has the potential to transform the lives of over 1.6 billion people who live without access to electricity Pico-solar systems are smaller and more affordable than traditional solar systems and have the power to provide useful amounts of electricity to charge the increasing number of low power consuming appliances from mobile phones, e-readers and parking meters, to LED lights which have the power to light up millions of homes in the same way the mobile phone has connected and empowered communities across the planet The book explains the important role pico-solar has in reducing reliance on fossil fuels while at the same time tackling world poverty and includes useful recommendations for entrepreneurs, charities and governments who want to participate in developing this exciting and rapidly expanding market John Keane is Managing Director and a founding member of SunnyMoney, the largest distributor of pico-solar lighting products in Africa Previously, he was Head of Programmes for SolarAid, the international NGO that set up and owns SunnyMoney He became acutely aware of the pressing need for affordable, renewable energy in off-grid communities from living in the village of Uhomini in rural Tanzania as a volunteer in 2000 He has since spent more than a decade leading and developing solar projects across east and west Africa and has played an instrumental role in building both SolarAid and SunnyMoney into respected international organisations Earthscan Expert Series Series editor Frank Jackson Solar: Grid-Connected Solar Electric Systems Geoff Stapleton and Susan Neill Pico-solar Electric Systems John Keane Solar Domestic Water Heating Chris Laughton Solar Technology David Thorpe Stand-alone Solar Electric Systems Mark Hankins Home Refurbishment: Sustainable Home Refurbishment David Thorpe Wood Heating: Wood Pellet Heating Systems Dilwyn Jenkins Renewable Power: Renewable Energy Systems Dilwyn Jenkins Energy Management: Energy Management in Buildings David Thorpe Energy Management in Industry David Thorpe Pico-solar Electric Systems The Earthscan Expert Guide to the Technology and Emerging Market John Keane Solar: Solar:Routledge Solar: Solar:Taylor & Francis Group Solar: ЭЯПШ Ш ] LONDON AND NEW YORK from Routledge First edition published 2014 by Routledge Park Square, Milton Park, Abingdon, Oxon OX14 4RN Simultaneously published in the USA and Canada by Routledge 711 Third Avenue, New York, NY 10017 Routledge is an imprint of the Taylor & Francis Group, an informa business © 2014 John Keane The right of John Keane to be identified as author of this work has been asserted by him in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988 All rights reserved No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data Keane, John (Urban planner) Pico-solar electric systems : the Earthscan expert guide to the Technology and Emerging Market / John Keane — First edition pages cm — (Earthscan expert series) Includes bibliographical references and index Building-integrated photovoltaic systems Small power production facilities Solar houses I Title TK1087.K43 2014 621.31′244—dc23 2013035359 ISBN: 978-0-415-82359-3 (hbk) ISBN: 978-1-315-81846-7 (ebk) Typeset in Sabon by Keystroke, Station Road, Codsall, Wolverhampton Contents Illustrations vii Preface xiii Acknowledgments xvii List of Abbreviations xix Introducing Pico-Solar The Solar Resource 15 Solar PV Cells and Modules 23 Batteries 39 Lighting 53 Appliances and Energy Use 59 Product Quality 85 Using, Maintaining and Repairing Pico-Solar Systems 97 The Impact of Pico-Solar in Developing Countries 109 10 Selling Pico-Solar at the Base of the Pyramid 123 11 Case Studies 147 12 Resources 169 Bibliography 173 Glossary 177 Index 181 This page intentionally left blank Illustrations Figures 1.1 Selection of pico-solar lights and charging systems, principally designed for use in areas without access to electricity 1.1a Pico-solar systems are used to provide power for a wide range of applications 1.1b A small portable charger with an integrated battery, PV module and LED light, also recharges mobile phones 1.1c A small, pico-solar powered, bike light 1.2 The sale of pico-solar lights in Africa, approved for quality by the Lighting Global programme, has increased significantly between 2009 and 2012 1.3a Pico-solar systems are smaller than traditional solar home systems 1.3b Large solar module dwarfing a pico-solar light and module 1.3c A solar light and phone charger taken apart to show the main components 1.4 Map demonstrating the largest un-electrified populations of the world in 2009 1.5 A composite image of the world at night 1.6 Incident solar radiation map 1.7 Kerosene lamps are a dangerous fire hazard, and are polluting, costly and emit low levels of light 1.8 The majority of households in rural Africa are not connected to the electricity grid 1.9 Children light candles in a school in Malawi during a power cut 1.10 Two students studying with one pico-solar light 1.11 Children playing with disposable batteries which have reached the end of their life in Rema, Ethiopia 1.11a Battery recycling box in Rome, Italy 2.1 Energy is transferred from the sun as light energy and then converted into electrical energy which charges up a rechargeable battery, where it is stored as chemical energy 2.2 1350 W/m2 of solar radiation arrives in the earth’s atmosphere 2.3 Direct and diffuse radiation 2.4 Solar irradiance in watts per square metre (W/m2), received over time on a flat surface in an equatorial region 2.5 The solar incident angle 2.6 Symbols used for direct current and alternating current 2.7 Voltage, current and power within the context of a simple circuit 3.1 A solar cell producing electricity 3.2 Sunlight hits the surface of the PV cell, which converts the light energy (photons) into electric current which flows to the terminals which are connected to a circuit 4 6 7 9 10 10 11 11 16 17 18 19 20 20 21 23 24 viii LIST OF ILLUSTRATIONS 3.3 Thirty-six solar cells wired together in series so as to achieve a higher voltage 3.3a A solar module made up of solar cells wired together 3.4 The back of a pico-solar module provides information such as power rating and operating specifications under test conditions 3.5 Silicon solar cell I-V curve which shows the maximum power point ‘the knee’ of the curve 3.6 Effects of radiation intensity on module output 3.7 Effects of temperature on module output 3.8 In full sunlight, the module shows a Voc reading of 21.24 V 3.9 The Voc reading drops to 20.73 V when the module is in the shade 3.10 In full sunlight, the Isc reading is 0.305 A 3.10a This reading drops significantly to 0.071 A 3.11 Monocrystalline cells 3.11a Monocrystalline modules 3.12 Polycrystalline cells 3.12a Polycrystalline modules 3.13 A thin film module can be recognised by its dark uniform appearance with lines running along the module 3.14 Flexible, Unisolar multi-junction thin film solar module 3.15 The junction box at the rear of a module projects the points where the cable and wiring connects to the module’s terminals 3.16 Average solar PV price per watt have fallen significantly between 2008 and 2012 4.1 Rechargeable batteries come in a range of different shapes, sizes and chemistries as well as different voltages and energy capacities 4.2–4.2a Pico-solar products typically incorporate the rechargeable battery 4.3 Circuit board of a pico-solar lantern and phone charger which incorporates charge control circuitry and a fuse 4.4 A pico-solar light with a digital display which tells the user how many hours of light remain 4.5 It is common to see a battery’s capacity defined as mAh on the side of the battery 4.6 Battery SoC at 20 per cent and 80 per cent 4.7 Measuring the voltage of a battery 4.8 The percentage degree to which a battery is discharged is referred to as depth of discharge (DoD) 4.9 3.6 V NiMH battery pack made up of three 1.2 V NiMH batteries connected together in parallel 4.10 3.2 V, 600 mAh LFP battery 4.11 V, 4.5 Ah sealed lead-acid battery 4.12 1.2V, 600 mAh NiCd battery 5.1 Luminous flux refers to visible light in every direction 5.2 One lux equates to the even distribution of lumen over an area of 1m2 5.3 A typical LED 5.4 LEDs come in a range of different shapes and sizes 5.5 This light has seven LEDs in the centre, surrounded by a large metallic plate which acts as a ‘heat sink’ 25 25 26 28 29 29 30 30 31 31 33 33 34 34 35 35 36 37 40 40 41 42 43 44 44 45 48 48 49 50 54 54 55 55 55 LIST OF ILLUSTRATIONS 5.6 Chart showing luminous efficacy of LEDs, CFLs and incandescent bulbs over time 6.1 AC/DC power adaptor for a laptop 6.2 AC/DC power adaptor for a mobile phone 6.3 The micro USB connector has become fairly standard as a connection type 6.4 This voltage converter converts 12 V (typical voltage of car batteries) down to V (typical voltage of USB outlets) 6.5 Pico-solar module facing the overhead sun 6.6 Designers of portable pico-solar chargers often have to compromise the size of the PV module so that the product can be carried around easily 6.7 An increasing number of pico-solar lamps incorporate a USB outlet 6.8 Solar module being used to charge a mobile phone directly in Zambia 6.9 A wide range of specialised solar chargers exist 6.10 Radio with an integrated solar module and rechargeable battery 6.11 This radio available in the Kenyan market uses a 3.7 V, 800 mAh rechargeable mobile phone battery instead of traditional disposable batteries to operate 6.12 This pico-solar light comfortably recharges a basic e-reader device 6.13 A tablet computer being recharged by a portable solar powered charger 6.14 This pico-solar system uses a Wp PV module and a 12 V, 7.7 Ah SLA battery, which is capable of recharging a tablet computer 6.15 Hand-held mobile television 6.16 Pico-projector with a 3.7 V, 1600 mAh battery 6.17 This pico-solar lantern has an integrated solar module and rechargeable battery 6.18 This light, charged by a separate solar module, can produce over 300 lumens for an hour at its maximum setting 6.19 This phone comes with an integrated pico-solar module of around 0.3 Wp 6.20–6.20a Device designed to provide useful back-up power for laptops on the go 6.21 Laptops with integrated pico-solar modules are appearing on the market 6.22 Solar backpacks come with an integrated solar module 6.23 Solar charged parking meter in Sicily, Italy 6.24 A solar-powered city bike hire station in Toronto 6.25 A solar powered electric fence unit 6.25a The unit can send an electric pulse along up to 30 km of electric fencing and is used to keep cows and other livestock at bay 6.26 Solar module being used to recharge an SLA battery 6.27 A 30 Wp solar lighting system with a 12 V 24 Ah SLA battery 7.1 To measure illuminance, position the photo detector of the lux meter so that it faces the light source 8.1 Instructions for how to use and recharge a pico-solar light 8.2 Keep modules free of dust and anything which prevents sunlight reaching the surface to maximise electricity generation 8.3 Customers need to know how to use systems properly to get the best out of them 8.4 Good products are built to withstand use in harsh conditions 57 60 60 61 63 65 68 69 70 70 71 72 73 74 74 75 75 76 76 77 78 79 80 80 81 82 82 82 83 91 99 100 100 101 ix 172 RESOURCES Selection of Pico-Solar Companies Specialising in Lighting Products for the Base of the Pyramid (BoP) Market This selection of companies is provided for information purposes only It is not intended to be a comprehensive list Table 12.1 Barefoot Power barefootpower.com Manufacturer Solux Service GmbH www.solux.org Manufacturer Schneider Electric schneider-electric.com Shanghai Roy Solar www.roysolar.com Manufacturer Manufacturer d.light design dlightdesign.com Manufacturer and Distribution fosera www.fosera.com Manufacturer Nokero www.nokero.com Manufacturer Sunlite www.sunlite.co.ke Manufacturer Greenlight Planet greenlightplanet.com Manufacturer and Distribution Kamworks www.kamworks.com Manufacturer and Distribution Thrive Solar Energy Ltd www.thriveenergy.co.in Manufacturer and Distribution SunnyMoney www.sunnymoney.org Distribution Solar Sisters www.solarsister.org Distribution Orb www.orbenergy.com One Degree Solar onedegreesolar.com Little Sun www.littlesun.com Manufacturer and Distribution Manufacturer Manufacturer Omnivoltaic www.omnivoltaic.com Manufacturer Pharos Off Grid www.pharosoffgrid.com Manufacturer Angaza Design angazadesign.com PAYG Manufacturer Azuri azuri-technologies.com PAYG Manufacturer Betta Lights www.bettalights.com Manufacturer Philips www.philips.com Manufacturer Trony www.trony.com SolarAid www.solar-aid.org Manufacturer Charity Waka Waka www.waka-waka.com Manufacturer Bibliography Adelman, P and Reindl, T (2012) Batteries for Pico PV Systems, Solar Energy Research Institute of Singapore (SERIS), National University of Singapore 3rd Lighting Africa Conference Agrawal, R and Dutt, N (2013) Distribution Channels to the Base of the Pyramid, Business Innovation Facility Issue Alstone P., Mills E and Jacobson A (2011) Embodied Energy and Off-Grid Lighting, The Lumina Project, Technical Report no Bandura, A (1993) ‘Perceived Self-Efficacy in Cognitive Development and Functioning’, Educational Psychologist, 28:2 (1993), pp 117–148 Battery University, http://batteryuniversity.com/learn/article/memory_myth_or_ fact BBC Future (International version) (2012) ‘Charging Tomorrow’s Smartphones’, http://www.bbc.com/future/story/20120227-charging-tomorrows-smartphones/1 Bond, T C., Zarzycki, C., Flanner, M G and Kock, D M (2011) ‘Quantifying Immediate Radiative Forcing by Black Carbon and Organic Matter with the Specific Forcing Pulse’, Atmospheric Chemistry and Physics, 11, 1505–25 BuildingTechnologies Program (2013) US Department of Energy, LED Basics, Energy Efficiency and Renewable Energy, http://www1.eere.energy.gov/ buildings/ssl/sslbasics_ledbasics.html City of Portland, Oregon (2011) Solar-Powered SmartMeters Streamline Portland’s Parking, http://www.portlandoregon.gov/bibs/article/157993 d.light (2013) at http://www.dlightdesign.com/impact-dashboard/customerbenefits/ Eco Design Notes (2012) Battery Toxicity and Eco Product Design, Lighting Global, Issue 1, September Esper, H., London, T and Kanchwala, Y (2013) Access to Clean Lighting and their Impact on Children: An Exploration of SolarAid’s SunnyMoney, Child Impact Case Study No Ann Arbor: The William Davidson Institute Godin, S (2010) ‘Marketing to the Bottom of the Pyramid,’ http://sethgodin typepad.com/seths_blog/2010/09/marketing-to-the-bottom-of-the-pyramid Government of India, Ministry of Home Affairs (2011) http://www.census india.gov.in/2011-prov-results/indiaatglance.html Government of India (2011) Census of India: Houses, Household Amenities and Assets Gruner, R., Lux, S., Reiche, K and Schmitz-Gunther, T (2009) Solar Lanterns Test: Shades of Light, Eschborn: GTZ, www.gtz.de GTZ (2010) What Difference Can a PicoPV System Make? Early Findings on Small Photovoltaic Systems – An Emerging Lowcost Energy Technology for Developing Countries Eschborn: www.gtz.de Guidelines to Defra/DECC’s GHG Conversion Factors for Company Reporting (2011) Produced by AEA for the Department of Energy and Climate Change (DECC) and the Department for Environment, Food and Rural Affairs (Defra) 174 BIBLIOGRAPHY Guryan, J (2008) ‘Parental Education and Parental Time with Children’, Journal of Economic Perspectives, American Economic Association, 22:3, 23–46 Hankins, M (2010) Stand-Alone Solar Electric Systems: The Earthscan Expert Handbook for Planning, Design and Installation, London: Routledge Hystra Hybrid Strategies Consulting (2013) Marketing Innovative Devices for the Base of the Pyramid, http://hystra.com/marketing-devices Kammen, D (2011) Chief Technical Specialist for Renewable Energy and Energy Efficiency at the World Bank, The Institute of Science in Society (ISIS) (2011) ISIS Report 06/04/11, http://www.i-sis.org.uk/LightingAfrica.php? printing=yes Lam, N., Smith K., Gauthier, A and Bates, M (2012) ‘Kerosene: A Review of Household Uses and their Hazards in Low- and Middle-Income Countries’, Journal of Toxicology and Environmental Health, Part B: Critical Reviews, 15:6, 396–432 Lam, N L., Chen, Y., Weyant, C., Venkataraman, C., Sadavarte, P., Johnson, M A and Bond, T C (2012) ‘Household Light Makes Global Heat: High Black Carbon Emissions from Kerosene Wick Lamps’, Environmental Science & Technology, 46:24, 13531–8 Lighting Africa (2010) Solar Lighting for the Base of the Pyramid – Overview of an Emerging Market, Lighting Africa Lighting Africa (2012) Market Trends Report – Overview of the Off-Grid Lighting Market in Africa, Lighting Africa Lighting Asia (2012) Solar Off-Grid Lighting: Market Analysis of India, Bangladesh, Nepal, Pakistan, Indonesia, Cambodia and Philippines, Lighting Asia 2012 Lighting Global Technical and Eco Design Notes Series, (2010–) at www lightingafrica.org Lysen, E (2012) Pico Solar PV Systems for Remote Homes: A New Generation of Small PV Systems for Lighting and Communication, IEA PVPS Task Report IEA-PVPS T9-12 Miller, D., (2010) Selling Solar: The Diffusion of Renewable Energy in Emerging Markets, London: Earthscan Mills, E (2005) ‘The Spector of Fuel-Based Lighting’, Science AAAS, 308, http://light.lbl.gov/pubs/mills_science_fbl.pdf Narasimha Desirazu Rao (2011) Distributional Impacts of Energy Policies in India: Implications for Equity, Stanford University Nique, M (2010) Off-Grid Handset Charging, Green Power for Mobile, Bi-Annual Report, November, http://www.gsma.com/mobilefordevelopment/ wp-content/uploads/2012/04/offgridhandsetcharging.pdf Prahalad, C K (2006) The Fortune at the Bottom of the Pyramid: Eradicating Poverty through Profits, Upper Saddle River, NJ 07458: Pearson Education Inc publishing as Prentice Hall Prugue, X (2012) Energy Poverty: India’s Best Kept Secret, United Nations Environment Programme (UNEP), http://new.unep.org/wed/blogs/Prugue4.asp Purdue University (2003) ‘Modeling Appropriate Behavior’, Parent Provider Partnerships Reddy, T (2010) Linden’s Handbook of Batteries, 4th edn New York: McGraw-Hill BIBLIOGRAPHY SolarAid (2012) Data from Follow up Interviews with 232 Pico-Solar Customers in Narok County in Kenya, Karonga District in Malawi and Kilimanjaro Region in Tanzania The Economist (2010) ‘Power to the People: Energy in the Developing World’ (2 September 2010), http://www.economist.com/node/16909923 UN (2007) Education is Key to Reducing Child Mortality: The Link between Maternal Health and Education, UN Chronicle, http://www.un.org/wcm/ content/site/chronicle/home/archive/issues2007/themdgsareweontrack/educati oniskeytoreducingchildmortalitythelinkbetweenmaternalhealthandeducation UN Press Release (2013) Sustainable Off-Grid Lighting Solutions Can Deliver Major Development and Climate Benefits, UNEP Announces new partnership with Global Off-Grid Lighting Association, at http://www.rona.unep.org/ documents/news/en%20lighten%20PR%20GC%20140213%20FINAL.pdf UN (2013) A New Global Partnership: Eradicate Poverty and Transform Economies through Sustainable Development: The Report of the High-Level Panel of Eminent Persons on the Post-2015 Development Agenda, at http:// www.un.org/sg/management/pdf/HLP_P2015_Report.pdf UNESCO (2005–2010 data) Regional Literacy Rates for Adults (15+), http://stats.uis.unesco.org/unesco/TableViewer/tableView.aspx?ReportId=201 UNESCO (2012) Education for All Global Monitoring Report: Youth and Skills: Putting Education to Work, http://unesdoc.unesco.org/images/0021/0021 80/218003e.pdf UNFCCC 2012: AMS-III.AR (2012) Substituting Fossil Fuel Based Lighting with LED/CFL Lighting Systems, at http://cdm.unfccc.int/methodologies/DB/ 41A0Q0QT5CUP3TMD57GC6RZ4YRV28M, p Verschelling, J and Diehl, J C (2010) Solar Lantern Development and Dissemination – From Participatory Design to Implementation in Rental Scheme, www.kamworks.com WBCSD Development (2013) Business Solutions to Enable Energy Access for All, The WBCSD Access to Energy Initiative, http://www.wbcsd.org/pages/ edocument/edocumentdetails.aspx?id=14165&nosearchcontextkey=true World Bank (2008) The Welfare Impact of Rural Electrification: A Reassessment of the Costs and Benefits, An IEG Impact Evaluation, http://lnweb90.world bank.org/oed/oeddoclib.nsf/DocUNIDViewForJavaSearch/EDCCC33082FF8 BEE852574EF006E5539/$file/rural_elec_full_eval.pdf World Bank (2011) ‘Early Childhood Development: Nutrition’, http://go.world bank.org/DL9AKYWQ70> in ibid World Bank, IFC, MIGA, Independent Evaluation Group (2010) ‘What Can We Learn from Nutrition Impact Evaluations: Lessons from a Review to Reduce Child Malnutrition in Developing Countries’, in ibid World Bank (2012) Mobilizing the Agricultural Value Chain, http://siteresources worldbank.org/EXTINFORMATIONANDCOMMUNICATIONANDTECH NOLOGIES/Resources/IC4D-2012-Chapter-2.pdf World Energy Outlook (2011) International Energy Agency, http://www.world energyoutlook.org/resources/energydevelopment/accesstoelectricity/ 175 This page intentionally left blank Glossary Alternating current (AC) – electric current that reverses direction in a circuit at regular intervals Amorphous silicon – type of thin film solar photovoltaic material Amp – unit of electric current which measures the flow of electrons passing a point in an electric circuit per unit time Amp-hour (Ah) – the amount of charge in a battery that will allow one amp of current to flow for one hour; used to indicate battery capacity Appliance – electronic device which uses electricity in order to operate, such as a phone or radio Base of the pyramid (BoP) – term used to define low income populations who typically live on less than USD 2.5/day; sometimes referred to as ‘bottom of the pyramid’ Battery – an energy storage device which stores chemical energy which can be drawn out as electrical energy to power electronic device Battery capacity – amount of electrical charge a battery is capable of storing; usually measured in amp-hours C-rate – measure used to explain how quickly a battery is being charged or discharged Charge controller – circuitry or device which is designed to protect rechargeable batteries by limiting the rate at which electric current is drawn from or added to rechargeable batteries, ensuring the battery is not overcharged or discharged Circuit – closed system of wires and conductors which allow electric current to flow Compact fluorescents (CFLs) – type of energy efficient light bulb Charge cycle – process of charging and discharging a rechargeable battery; batteries can operate for a finite number of charge cycles; the number of charge cycles is used to explain a battery’s lifespan Depth of discharge – the amount of charge removed from a battery, expressed as a percentage of the total battery capacity Direct current (DC) – electric current flowing in one direction; pico-solar systems typically only use direct current Electric current – the rate of flow of electrons in a circuit Heat sink – component, usually metal, that cools a device by dissipating heat; used to prolong LED life by preventing overheating and potential damage Ingress protection (IP) – rating system used to explain degree to which a product is protected against the intrusion of water and solid objects and dust I-V curve – relationship between the electric current and voltage produced by a solar cell or module – plotted on a graph; used to determine performance at different levels of insolation and temperature Illuminance – the degree to which a surface area is illuminated; measured in lux Insolation – measure of solar radiation energy received on a surface area and at a given time; also called solar insolation 178 GLOSSARY Irradiance – solar radiation incident on a surface per unit time; measured in watt per square metre (w/m2) Light-emitting diode (LED) – an efficient semiconductor light source which dominates the pico-solar sector; uses include general lighting and as a charge controller indicator Lithium ion – umbrella name used to categorise range of different lithium-based rechargeable battery chemistries Load – appliance which uses electrical power Low voltage disconnect – control circuit which automatically disconnects circuit when voltage falls below a set voltage threshold to prevent battery from overdischarging Lumen – unit measure of the total amount of visible light emitted by a light source Luminous efficacy – the efficiency with which electrical power is converted into light; measured in lumens per watt (lm/w) as the ratio of light output to power input Luminous flux – the total amount of visible light emitted in all directions by a light source; measured in lumens Luminous intensity – how bright a light appears to be in a particular direction; measured in candelas (cd) Lux – a measure of the intensity of visible light that hits surface; one lux equals one lumen per square metre (l/m2) Maximum power point – the point at which a solar module produces the most power; clearly identifiable on an I-V curve Micro-solar – see pico-solar Milliamp-hour (mAh) – one thousandth of an Amp-hour (0.001Ah), commonly used to indicate capacity of pico-solar batteries Multimeter – an instrument with multiple settings, used to measure electrical units such as voltage, current and resistance Non-government organisation (NGO) – organisation operating independently from government, normally on a not for-profit basis Nickel-cadmium – type of rechargeable battery Nickel-metal hydride – type of rechargeable battery Off-grid – term used to refer to households and communities which are not connected to the main electricity grid Ohm – unit of resistance Open-circuit voltage (Voc) – the maximum voltage measured across a solar module when no load is attached and no current is flowing Peak sun hour – the equivalent number of hours each day, during daylight, when solar irradiance averages 1000 w/m2; used to calculate system sizes as more peak sun hours mean a solar PV module can produce more electricity Photovoltaic (PV) – refers to the conversion of sunlight (solar radiation) into electric current Pico-solar – term used to define products and systems which utilise small solar pv modules, typically below 10 W peak PicoPV – see pico-solar Potential difference (voltage) – the potential difference in energy between two points in a circuit which governs the flow of electric current; measured in volts GLOSSARY Rechargeable battery – battery which can be used and recharged multiple times, though multiple ‘cycles’ Resistance – property of circuit or appliance which resists the flow of electric current, resulting on some electrical energy being converted to heat energy; measured in ohms Sealed lead-acid (SLA) – type of rechargeable battery Self-discharge – term used to explain the fact that batteries slowly discharge when not in use Short circuit current (Isc) – current through a solar cell when the voltage is zero Social enterprise – organisation that applies commercial strategies to maximise social and environmental improvements Solar cell – a semiconductor electrical device that converts the light energy into electricity Solar lantern – lantern which contains a rechargeable battery and incorporates or is powered by a separate solar module Solar module – groups of solar cells wired together and encapsulated to generate electrical power Solar constant – amount of radiation arriving at the edge of the earth’s atmosphere from the sun Solar home system (SHS) – an off-grid solar system used to provide power for households – usually for lights and small appliances; solar-home-systems typically use modules between 10 Wp and 100 Wp rating and include a charge controller and rechargeable sealed lead-acid battery Solar incident angle – angle at which sunlight hits a surface Standard test conditions (STC) – accepted set of common test conditions used by manufacturers to test and compare solar modules; the conditions are: 1000 W/m2 solar irradiance at 25oC and Air Mass 1.5 State of charge (SoC) – the amount of charge in a battery, expressed as a percentage of the total battery capacity Thin film – type of solar PV cell and module made by depositing thin layers of photovoltaic material on a substrate Tracking – changing the position of a solar module during the day so that it follows and faces the sun as it moves across the sky USB – abbreviation referring to an increasingly common connecting plug and socket which operates at volts Volt (V) – unit used to measure electric potential at a given point in an electric circuit; often referred to ‘the force’ which causes electrons to flow Watt (W) – unit measurement of power; one amp multiplied by one volt = one watt Watt-hour (Wh) – energy measure, calculated by multiplying power (watts) by hours Watt-peak (Wp) – maximum power output generated by a PV module under standard test conditions 179 This page intentionally left blank Index Notes (1) The word order is letter by letter; (2) Locators to photographs, plans and tables are in italics; and (3) Locators in bold refer to entries in the glossary absorbed glass matt batteries (‘AGM’) 49, 50 AC/DC power adaptors 60 Addis Ababa (Ethiopia) 20 advertising 102, 149, 160 see also sales promotions Africa 5, 8, 9, 110, 112, 127 after-sales service 97, 101, 140–1 see also distribution agricultural economies see rural communities air freight 97, 126 alternating current (AC) 20, 59, 177 Amazon kindle 156 amorphous silicon (a-Si) 34–5, 177 see also thin film modules amp-hours (Ah) 21, 43, 177 amps (A) 21, 177 angle of tilt see solar incident angle animal fat lighting 110–11 see also flame based lighting appliances 177; larger 81–3; small 59–61, 63 Argentina 110–11 Asia 5, 7, autonomous run times 41, 67, 90, 92–3 see also battery capacity Azuri (company) 135, 136 backpacks 79, 80 barriers see financial barriers; infrastructure Base of the Pyramid (BoP) 123–4, 138–40, 172, 177 see also low income households batteries 39–52, 177; chemistries 46–51, 125; discharge 43–4, 46, 97–8; disposal 11, 51, 106; effect of temperature 46; e-readers 156; innovation 51–2; lifespan 45, 143; pico-solar systems 4, 71; replacing 104–6, 141; state of charge (SoC) 44; voltage 66; warranties 140 see also charge cycles battery capacity 42–3, 59–60, 67, 177 see also autonomous run times below the line marketing 139 bike hire station 82 bike light books 155 see also e-readers brands 139–40 build quality check lists 89 burns 115 business models 129–32; local manufacturing 151–3; microfinance institutions (MFIs) 131, 166–8; pull marketing strategies 159–63; rural sales agents 130, 148–50, 158–9; sales promotions 153–5; schools 130, 155–8; social enterprises 163–5 business opportunities 113, 114 cables 107–8 cadmium telluride (CdTe) 34 see also thin film modules Cambodia 163–5 cameras 69–70 candela (cd) 53 capacity see autonomous run times; battery capacity catalogue orders 129 see also distribution CE marks 87 Chankhanda school (Mzigawa, Zambia) 151 charge control circuitry: electric fence unit 82; pico-solar systems 3, 6, 28, 42; purpose 40, 48–9 charge controllers 177; absorbed glass matt batteries (‘AGM’) 50; electrical protection 95; explanation of 90; picosolar systems 6, 45; rechargeable batteries 39–40, 46–7 charge cycles 45, 177 see also batteries; C-rates; depth of discharge (DoD) charging systems 3, 5, 68–9, 88 checklists 89–90 children 115–18 see also studying China 126 182 INDEX circuits 21, 177 cleaning 100 cloudy weather see solar radiation CO2 emissions 118 Colombo (Sri Lanka) 65 communications 118–20 community-based sales 129, 159 see also sales compact fluorescents (CFLs) 54, 56, 57, 177 see also lighting compatibility 59–61 computers 59–61, 73–4, 77–9 consumer awareness 138–9 consumer finance: defaults 136–7, 168; microfinance institutions (MFIs) 131, 137–8, 163, 166–8; Pay as You Go (PAYG) 129, 134–7; and solar uptake 11–12 see also financial barriers convenience 101 copper indium gallium selenide (CIS/CIGS) 34 see also thin film modules C-rates 42–4, 177 see also charge cycles crystalline silicon (c-Si) 37 current-voltage curves see I-V curves customer relationship management (CRM) 140, 150 customers 98, 133, 153–5, 163 customer service 97, 101, 140–1 daily energy demand 62–4 Dalberg Global Development Advisors 128, 133 death 115–16 Decade of Sustainable Energy for All 2014–2024 (UN) 13 defuse radiation 18 Delhi (India) 65 Department of Energy and Climate Change (DECC, UK), 118 depth of discharge (DoD) 45–6, 49, 177 see also charge cycles Deutsche Gesellschaft für Technische Zusammenarbeit GmbH (GTZ) 85 development 10, 109–11, 112 direct charging 69 direct current (DC) 20, 59–60, 81–3, 177 direct delivery 129, 131 see also distribution direct radiation 18 direct-to-village distribution (DTV) 158–9 discharge rates 43–4 see also depth of discharge (DoD) discounts 154 disposable batteries 11, 39 disposable income 116–17 see also low income households disposal: of batteries 11, 51, 106; of compact fluorescents (CFLs) 56; of PV modules 32, 36 see also pollution; recycling distribution 97–8, 125–32, 158–9, 163 see also after-sales service donkey manure lighting 110–11 see also flame based lighting door-to-door sales 129 dust 100 dye-sensitized thin-film PV modules 37 Early Childhood Development (ECD, World Bank) 116 earth, absorption of solar energy 16, 17 ease of use 2, 90, 97 East Africa 126, 148–50 eco-designs 143 Edison, Thomas 15, 120 education 116–18, 148, 155–8 see also schools; studying Education for all global monitoring report 2012 (UNESCO) 118 electric current 20–1, 23–4, 177 electric fences 82 electricity: access to 1–2, 5, 109–10 see also off-grid encapsulation 26 energy: costs 113; definition 17; demands 62–4; measure 21 energy sales agents 168 environmental impacts 57, 118 see also disposal; recycling equator 64–5 e-readers 61, 72–3, 155–8 Ethiopia 20 e-waste 144, 145 see also recycling eyeball tests 88, 89–90 eye strain 117, 121 farmers 119, 120 see also rural communities feed-in-tariffs (FiTs) 133 financial barriers: market infrastructure 11–12, 129–32, 153; upfront costs 11–12, 133–4, 153–4, 163 see also consumer finance flame-based lighting 110–11, 115, 117, 121 see also kerosene; lighting food spending 113, 116 Ford, Henry 138 Fortune at the Bottom of the Pyramid, The (Prahalad) 128 fosera GmbH & Co KG 151–3 Fraunhofer Institute Test Laboratory 94 free products 145 frequently asked questions (FAQs) 98, 99 functionality 101 INDEX Gates, Bill 11, 113 ‘Gel cell’ batteries 49 Ghana 153–8 Global LEAP 74, 171 Global Off-Grid Lighting Association (GOGLA) 144, 170 global warming Godin, Seth 138 Gondwe, Mphatso 118 governments 133, 144–6 Greenlight Planet 158–9 GTZ (Deutsche Gesellschaft für Technische Zusammenarbeit GmbH) 85 guarantees see warranties Guryan, Jonathan 119 hard-to-reach target markets 138–9 Harmonised System (HS, WCO) 86, 88 health and safety 101, 113–16 heat, effect of 28, 29 heat sinks 177 high-intensity solar regions 18 History of the World in 100 Objects (BBC/British Museum) home laboratory tests 90 homework 10, 117–19, 121, 149, 161 see also education household expenditure 112, 117 see also incomes HS codes 86, 88 Hystra consultancy 123–4, 139, 140 IEC/Technical Specification 62257-95:2013(E) 171 illnesses 115 illuminance 53, 54, 90, 177 import taxes 142–3 incandescent light bulbs 54, 56, 57 incident solar radiation map incomes 116–17, 125 see also household expenditure; low income households India: case studies 158–63; kerosene lanterns 110; peak sun hours (PSH) 65; pico-solar manufacturing 127; Solar Home Systems (SHS) 112 indirect charging 68–9 indoor air pollution 113–14 information services 138, 171 infrared 16 infrastructure 12, 153 ingress protection (IP) 67, 87, 177 injuries 115 innovations: batteries 51–2; LightEmitting Diodes (LEDs) 58; solar PV modules 37 insolation 19–20, 64–5, 177 installation 64–6 instructions 99 integrated pico-solar systems 157, 158 integrating sphere 92 International Electrotechnical Commission (IEC) 96, 171 international standards 86–8, 141 IP Code 67 87 irradiance 19, 20, 178 see also solar radiation Isc (short-circuit current) 27, 28, 31, 106–7 I-V curves 27–8, 177 junction boxes 35–6 Kamworks Solar Ltd 163–5 Kenya 65, 148–50 Kenya Bureau of Standards (KEBS) 87 kerosene: dangers 9, 113–14, 116; environmental impact 8, 118; lights 110, 111, 148–50; price 13; sale 134; spending on 112; storage 116, 134; subsidies 145 see also flame-based lighting key pads 136 laboratory tests 90–5 Lam, N L 114, 115 Laos 137 laptop computers 59, 77–9 see also tablet computers LCO see lithium cobalt oxide (LiCoO2) lead-acid batteries see sealed lead-acid batteries (SLA) LFP batteries see lithium iron phosphate batteries (LiFePO4) light-emitting diodes (LED) 54–8, 57, 61, 63, 88, 178 lighting 53–8, 109–11 see also flame-based lighting; pico-solar lighting; solar lighting systems Lighting Africa: effect of kerosene 118; electricity grid 5; pico-solar ownership 112, 138; poster 121; Quality Test Methodology (QTM) 95–6; value chain 132; World Bank-IFC programmes 169–70 Lighting Asia 112, 169–70 Lighting Global 3, 31, 94, 169–70 light output tests 90, 91 lithium cobalt oxide batteries (LiCoO2) 45, 47, 48 lithium ion batteries (Li-ion) 4, 47, 88, 140, 178 lithium iron phosphate batteries (LiFePO4) 4, 41, 45, 47, 48–9 load 178 loans 167 see also consumer finance 183 184 INDEX logistics 125–7 low energy lighting 1–2 low income households 123, 133, 139, 140 see also Base of the Pyramid (BoP); incomes low voltage disconnect 45, 178 lumen depreciation 56 lumens (lm) 53, 178 LuminaNET 170 luminous efficacy 54, 57, 178 luminous flux 53, 54, 178 luminous intensity 53, 178 lux 53, 54, 178 lux meter 90 maintenance 98–9, 100–1, 157 maize husks lighting 110 see also flame-based lighting Malawi 117, 126, 148–50 manufacturing 126–7, 132, 151–2 Maputo (Mozambique) 151–2 market infrastructure 12 marketing 123–46, 150, 162–3 mass communications 118–20 maximum power point 28, 66, 178 see also I-V curves Mbewe, Stella 114 media dark areas 138 microfinance institutions (MFIs) 131, 137–8, 163, 166–8 see also consumer finance micro-solar see pico-solar Miller, Damian 11–12, 162 milliamp-hour (mAh) 178 minimum standard tests 94–5 see also testing M-KOPA Solar 134–5 mobile banking services 120, 134–5 mobile phones: batteries 41; direct current (DC) 59; energy consumption 61, 63; impact 10–11; marketing 140, 150; mass communication 118–19; recharging 69–71, 77; repairing 142 see also smartphones mobile televisions 74, 75 ‘Mobilizing the Agricultural Value Chain’ (World Bank) 119 module output 27–31, 66 see also solar modules module size 63–4, 66 module Voc 66 see also open-circuit voltage (Voc) money savings: and education 116–17; energy 5, 101, 112–13, 163, 166; mobile phones 70; reliance on batteries 72, 101; sales promotion 154 monocrystalline silicon cells 4, 24–6, 28, 32, 33 MoonLight solar lanterns 163–5, 165 Mozambique 127, 151–3 M-PESA 120, 134–5 Mtei, Joyce 117 Mtei, Sinsolesa 117 multi-junction amorphous silicon 35 multimeters 106, 178 multiple power sources 72 Nairobi (Kenya) 65 national standards 87 Negros Women for Tomorrow Foundation (NWTF) 166–8 nickel cadmium batteries (NiCd) 45, 47, 50–1, 88, 178 nickel-metal hydride batteries (NiMH) 4, 41, 45, 47, 48, 88, 178 non-government organisations (NGO) 178 notebooks 77–9 see also computers off-grid 178; Africa 2, 110, 148; India 109, 158; locations 7; penetration rates 13; population growth see also electricity, access to ohms (Ω) 21, 178 open-circuit voltage (Voc) 23, 28, 29, 66, 106, 178 operating voltages 59 Orb Energy 159, 162–3 organic photovoltaics (OPV) 37 Parental Education and Parental Time with Children (Guryan) 119 parking meters 4, 79, 80 partnerships 129, 130 see also distribution Pay as You Go (PAYG) 129, 134–7 see also consumer finance peak power 26 see also watt-peak (Wp) peak sun hours (PSH) 19–20, 65, 66, 178 performance: pico-solar systems 27–8, 88–9; students 117–18 Philippines 166–8 phone chargers 6, 42 photons 24 photosynthesis 15 photovoltaics (PV) 23, 37, 178 pico-projectors 74, 75 pico-solar 1, 67, 112–21, 178 pico-solar industry 12–13, 124 pico-solar lanterns: advertising 102; circuit board 42; laboratory tests 85; market penetration 13, 112; performance specifications 88; range of 76; recharging phones 62; USB outlets 69 pico-solar lighting: businesses using 114; components for 3; home use 119; INDEX impact 10–11; sales 148–50; settings 42; studying by 10, 121, 149 see also lighting pico-solar market 5, 128 pico-solar phones 77 see also mobile phones pico-solar PV modules 6, 31–2 see also solar modules pico-solar PV systems: autonomy period 41; batteries 39; capacity 62; components 3–4; direct current (DC) generation 59; powering radios and phones 119; principles 15; solar home systems see also solar home systems (SHS) plug and play systems 2, 162 poisoning 115 pollution 57, 113–14, 118 see also disposal; toxicity polycrystalline silicon cells 4, 24–6, 34, 35 portable appliances 1–2, 4, 41, 67–80 positioning modules 64–6 potential difference (voltage) 178 poverty 113 see also low income households power, definition 17 power adaptors 59, 60 power consumption 62–4 power cuts 10 power outlets power output 27–31 Prahalad, Coimbatore K 128, 139 Pretoria (South Africa) 65 prices: of components 12–13; entry level lights 112; kerosene 13; Light-Emitting Diodes (LEDs) 58; PV modules 37; solar modules 133 product collection infrastructure 143–4 see also recycling product failure 140 product life 86, 143 product performance 86–9 product quality 85–96, 141–2 promotional materials 102, 149 proprietary distribution 128, 130 see also distribution Puerto Rico 65 pull marketing strategies 162–3 purchasing costs 133, 153–5, 163 see also consumer finance; financial barriers quality assurance 95–6 quality marks 85–6, 87 radiation see solar radiation radios 61, 63, 71, 118–19 ratings 26 reading see e-readers; studying rechargeable batteries 3, 39–40, 43, 72–3, 156, 179 recharging appliances 62, 69–71 recycling: batteries 11, 51; compact fluorescents (CFLs) 56; e-waste 143–4; lead-acid batteries 50; PV modules 36 see also disposal renting 137 repairs 90, 103–8, 141, 142 resistance 179 respiratory sicknesses 114 Restriction of Hazardous Substances (RoHs) 87 retailers 129, 130, 132, 167 Roberts solarDAB radio 71 rooftops 28 rural communities: distribution difficulties 127–8; farmers 119, 120; isolation 119; as media dark areas 138; seasonal incomes 125 rural electrification see off-grid rural entrepreneurs 130 saathis 159, 161 Safaricom 77 sales: community-based 129, 159; incentives 168; pico-solar lights sales agents 159, 160, 168 sales promotions 154 see also advertising San Juan (Puerto Rico) 65 schools: dormitory fire 115; e-readers 155–8; power cuts 10 see also education scratch cards 135, 136 sealed lead-acid batteries (SLA) 4, 39–40, 45–7, 49–50, 51, 88, 179 seasonal incomes 125 see also incomes self-discharge 46, 179 Selling Solar (Miller) 11–12 Serios, Raymond 112, 168 servicing 103 see also repairs shading, module output 29–30, 31, 65 shipping 97–8, 125–6 see also distribution Shirima, Paul 114 short-circuit current (Isc) 27, 28, 31, 106–7 silicon solar cell 24, 28 smartphones 51–2, 69–71 see also mobile phones social enterprises 163, 179 social networks 170 SolarAid 112, 116, 117 solar backpacks 79, 80 solar battery chargers 88 solar cells 23–4, 179 solar constant 16, 179 solar energy 15–20 see also sun, the 185 186 INDEX solar home systems (SHS) 6, 13, 41, 112, 179 see also pico-solar PV systems solar incident angle 19, 20, 64–5, 179 solar insolation values see insolation solar irradiance see irradiance solar lanterns 179 solar lighting systems 6, 83 see also lighting solar modules 179; damaging 101; disposal 32, 36; effect of heat 28–9; HS codes 88; innovation 37; maintenance 100–1; making 24–6; output 27–31, 66; pico-solar 6, 31–2; positioning 64–6; prices 37, 133; principles of 15–16; ratings 26; repairs 106–8; size 63–4, 66; types 31–5; wiring 35–6, 107–8 solar parking meters 4, 79, 80 solar photovoltaics 23 solar radiation 16–18, 28, 29 solar radios see radios solar spectrum 16 solar uptake, barriers to 11–12 see also financial barriers Solectric Plug and Play system (Orb Energy) 162 Sonitec radio 72 South Africa 65 South America 5, 7, Southern Africa 148–50 Sri Lanka 65 standards 85–96 standards of living 118 Standard Test Conditions (STC) 26, 27, 179 state of charge (SoC) 44, 98, 179 studying 10, 117–19, 121, 149, 161 see also education sub-Saharan Africa 110 sun-connect 171 Sun KingTM 159–60, 160; Eco light 99; Pro light 105 Sunlabob Renewable Energy 137 SunnyMoney (social enterprise) 102, 117, 148–50 sun, the 15, 64–5 see also solar energy supply chains 97–8, 125–6 see also distribution Sustainable Energy for All (UN) 171 tablet computers 59–61, 73–4 see also laptop computers; notebooks Tanzania 115, 143, 148–50 taxes 142–3, 145, 151–2 teachers 117 see also education technologies 4, 37 televisions 74, 75 temperature 28–9, 46 testing 90–5, 106 text messages 150 thin film modules 4, 34–5, 37, 179 toxicity 51, 56, 57 see also pollution Toyola Energy Limited 153–5 Toyola Money Box 154 tracking 179 traffic signs 81 training 141, 159 transporting goods 97–8, 125–6 see also distribution travellers 67, 80 troubleshooting 103, 104 trying before buying 154 ultraviolet 16 ‘unarticulated needs’ 138 un-electrified populations see off-grid UNESCO, Education for all global monitoring report (2012) 118 United Nations, Decade of Sustainable Energy for All (2014–2024) 13 upfront costs 133, 153–4, 163 see also consumer finance USB outlets 68–9, 69, 179 value chain 129, 132 village entrepreneurs 129 see also distribution villages 139 visible radiation 16 Voc (open-circuit voltage) 23, 28, 29, 66, 106, 178 voltage converter 63 voltages 59, 62 volts (V) 21, 179 Wahab, Suraj 155 warranties 86, 88, 102–3, 140–1 watt-hours (Wh) 21, 43, 179 watt-peak (Wp) 21, 26, 179 watts (W) 21, 179 WBCSD Development 124 well-being 118 West Africa 153–8 wet cells 49 white light 57 William Davidson Institute (WDI) 115, 116 word of mouth sales 159 see also sales working capital 132, 153 World Bank 114, 116, 119 World Bank-IFC programmes 3, 169–70 World Customs Organisation (WCO) 86 Worldreader 155–8 Zambia 110, 134, 148–51 ... editor Frank Jackson Solar: Grid-Connected Solar Electric Systems Geoff Stapleton and Susan Neill Pico- solar Electric Systems John Keane Solar Domestic Water Heating Chris Laughton Solar Technology... range of pico- solar product examples and provides an overview of the pico- solar markets across the world Chapter explains basic solar principles and how they relate to pico- solar electric systems. .. between 2009 and 2012 1.3a Pico- solar systems are smaller than traditional solar home systems 1.3b Large solar module dwarfing a pico- solar light and module 1.3c A solar light and phone charger