Table Of ContentSolar Electricity Handbook
A simple, practical guide to solar energy: how to design and install photovoltaic
solar electric systems
2012 Edition
Michael Boxwell
www.GreenstreamPublishing.com
Greenstream Publishing
12 Poplar Grove, Ryton on Dunsmore, Warwickshire, CV8 3QE. United
Kingdom
Copyright © Michael Boxwell 2009–2012
Published by Greenstream Publishing 2012
Smashwords Edition: ISBN 978-1-907670-23-7
Kindle Edition: ISBN 978-1-907670-22-0
First Edition – published April 2009
Second Edition – published November 2009
Third Edition – published March 2010
Fourth Edition – published January 2011
Fifth Edition – published October 2011
Sixth Edition – published February 2012
Editor: Sheila Glasbey
Michael Boxwell asserts the moral right to be identified as the author of this
work.
A catalogue record for this book is available from the British Library.
Whilst we have tried to ensure the accuracy of the contents in this book, the
author or publishers cannot be held responsible for any errors or omissions found
therein.
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system, or transmitted, in any form or by any means, electronic,
mechanical, photocopying, recording or otherwise, without the prior permission
of the publishers.
Table of Contents
Table of Contents
Introducing Solar Energy
Who this book is aimed at
The rapidly changing world of solar energy
Solar electricity and solar heating
The source of solar power
The principles of solar electricity
Understanding the terminology
Setting expectations for solar electricity
Why choose a solar electric system?
Cost-justifying solar
Solar power and wind power
Fuel cells
Grid-tied solar electric systems
Solar electricity and the environment
Environmental efficiency: comparing supply and demand
In conclusion
A Brief Introduction to Electricity
Don’t panic
A brief introduction to electricity
How to measure electricity
The relationship between volts, amps, ohms, watts and watt-hours
Volts
Power
Energy
A word for non-electricians
In conclusion
The Four Configurations for Solar Power
Stand-alone/off-grid
Examples of simple stand-alone systems
Grid-tie
An example of a grid-tie system
Grid-tie with power backup (grid interactive)
An example of a grid interactive system
Grid fallback
An example of a grid fallback system
Grid failover
How grid-tie systems differ from stand-alone
In conclusion
Components of a Solar Electric System
Solar panels
Batteries
Controller
Inverter
Electrical devices
Connecting everything together
A stand-alone system
A grid-tie system using a single central inverter
A grid-tie system using multiple micro-inverters
In conclusion
The Design Process
Short-cutting the design work
Solar energy and emotions
In conclusion
Scoping the Project
Designing grid-tie or grid fallback systems
Comparing supply with demand
Fleshing out the scope
Producing a power analysis
A word of warning
When you are ready to proceed
Calculating inefficiencies
Adding the inefficiencies to our power analysis
When do you need to use the solar system?
Keeping it simple
Improving the scope
In conclusion
Calculating Solar Energy
What is solar energy?
Why is this useful?
Calculating solar irradiance
Capturing more of the sun’s energy
The impact of tilting solar panels on solar irradiance
Calculating the optimum tilt for solar panels
Getting the best from solar panels at different times of the year
Positioning your solar panels
Using solar irradiance to work out how much energy a solar panel will
generate
Using solar irradiance to give you an approximate guide for the required
power capacity of your solar array
Solar panels and shade
Solar array power point efficiencies
The effects of temperature on solar panels
Temperature impact on solar performance in Austin, Texas during the
summer months
Working out an approximate cost
What if the figures do not add up?
Working out dimensions
In conclusion
Surveying Your Site
What we want to achieve
What you will need
First impressions
Drawing a rough sketch of the site
Positioning the solar array
Roof-mounting
Ground-mounting
Pole-mounting
Splitting the solar array into several smaller arrays
Identifying the path of the sun across the sky
Shading
Professional tools for obstacle analysis
Cell phone applications
Using paper and pencil
Future proof your system
What if there are shading obstructions?
Positioning batteries, controllers and inverters
Cabling
Site survey for the holiday home
In conclusion
Understanding the Components
How to use these chapters
Common components for all systems
Solar panels
Amorphous solar panels
Polycrystalline solar panels
Monocrystalline solar panels
Which solar panel technology is best?
What to look for when choosing a solar panel
Buying cheap solar panels
Second-hand solar PV panels
Fresnel lenses and mirrors
Solar panel mountings
Solar trackers
Solar array cables
Fuses and isolation switches
Ground fault protection
Components for Grid-Tie systems
High voltage in-series
Low voltage systems
Micro-inverter systems
Grid-tie solar panels
Grid-tie inverters
Input voltage
Power rating
Power tracking
Multiple strings
Diagnostics and reporting information
Built-in safety
Installation options and operating environment
Buying from eBay
Components for Stand-Alone Systems
Calculate your optimum voltage
Voltages and currents
What voltages can I run at?
How to work out what voltage you should be running at
How to calculate your current
Calculating cable thicknesses
Converting wire sizes:
Mixing and matching solar panels
Batteries
Types of batteries
Battery configurations
Battery lifespan
Holdover
Calculating how long a set of batteries will last
Second-hand batteries
Building your battery bank
Battery safety
Solar controller
Balancing the batteries
Allow for expansion
Maximum power point tracking
Ground fault protection
Backup power
Using multiple controllers
Inverters
Battery bank voltage
Power rating
Waveform
Installation options and operating environment
Ground fault protection
Cables
Battery cables
Appliance cabling
Plugs and sockets
Appliances
Lighting
Refrigeration
Microwave ovens
Televisions, DVDs, computer games consoles and music
Music systems
Dishwashers, washing machines and tumble dryers
Air conditioning systems
Reputable brand names
Solar panel manufacturers and brands
Solar controller and inverter manufacturers and brands
Battery manufacturers and brands
Shopping list for the holiday home
In conclusion
Planning, regulations and approvals
National and international standards for solar components
Installation regulations
Getting your electricity supplier involved
Solar grants and selling your power
General information about grants, tax credits and feed-in tariffs
In conclusion
Detailed Design
Safety is designed in
What is the worst that can happen with a solar installation?
Grounding your electrics
DC Electrics
AC electrics
High temperatures
Think safety
Solar array design
Solar array design – stand-alone systems
Solar array design – grid-tie systems with micro-inverters
Solar array design – grid-tie systems with a single inverter
Batteries
Controller
Inverter
Devices
Specifics for a grid fallback system
Circuit protection
Earthing (grounding)
DC circuit protection
AC circuit protection
Cable sizing and selection
Sizing your cables
Protecting cable runs
Designing your system to keep your cables runs as short as possible
