To Catch the Sun: Inspiring stories of communities coming together to harness their own solar energy, and how you can do it too! (To Catch the Resources)

207 Pages·2021·16.616 MB·English

by  Lonny Grafman, Joshua M. Pearce

TO CATCH
THE SUN
Inspiring stories of communities coming
together to harness their own solar
energy, and how you can do it too!
Lonny Grafman | Joshua Pearce
Humboldt State University Press
HSU Library
1 Harpst Street
Arcata, California 95521-8299
[email protected]
www.tocatchthesun.com
Copyleft © 2021 by Lonny Grafman and Joshua Pearce
This work is licensed under a Creative Commons
Attribution-ShareAlike 4.0 International License.
Please reproduce parts of this book to make
solar power more accessible to all.
When doing so, please link back to the book, and
following the CC BY-SA 4.0 guidelines.
Cover design by Ana Emma Mejía
Interior design and layout by Marian Voicu of Layouts.ro
Reviewing and advising provided by many Appropedians
ISBN 13: 978-1-947112-62-9
Library of Congress Control Number: 2021947789
10 9 8 7 6 5 4 3 2 First Print
Dear reader,
Thank you for your interest in small scale
solar power. We appreciate you and hope you
love this book!
 If you haven't already, please sign up at tocatchthesun.com for
the most up-to-date information and to learn about upcoming
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 Spread the word to people you know, on social media (with the
hashtag #tocatchthesun), and by writing a review on your favorite
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 Share your projects and photos with us on social media or by
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 Add us to your social media networks at:
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195
Joshua Pearce Lonny Grafman
Dedicated to
people like you
working to make the world
a little bit better every day.
Table of Contents
Foreword.............................................................................................................ix
1. Introduction....................................................................................................1
1.1. From Joshua..................................................................................................................................1
1.2. From Lonny..................................................................................................................................2
1.3. Who this book is for and how to read it.......................................................................................4
2. Solar Stories ...................................................................................................7
2.1. Schatz Energy Research Center, US............................................................................................7
2.2. Chiapas, Mexico........................................................................................................................10
2.3. La Yuca, Dominican Republic..................................................................................................13
2.4. G2G Animal Shelter..................................................................................................................18
2.5. Baraut, India .............................................................................................................................21
2.6. Parras de la Fuente, Mexico.......................................................................................................27
2.7. Las Malvinas, Dominican Republic..........................................................................................30
3. Solar concepts............................................................................................... 33
3.1. Solar power.................................................................................................................................33
3.2. Photovoltaics..............................................................................................................................36
3.3. Costs..........................................................................................................................................48
3.4. Photovoltaic effect......................................................................................................................55
3.5. Types of panels...........................................................................................................................58
3.6. Insolation, full sun power, peak sun hours................................................................................68
3.7. Storage and days of autonomy....................................................................................................70
3.8. Efficiency....................................................................................................................................71
4. Electricity..................................................................................................... 75
4.1. DC concepts ..............................................................................................................................75
4.2. Series and parallel......................................................................................................................76
4.3. Power and Energy......................................................................................................................82
v
4.4. IV curves ...................................................................................................................................84
4.5 Safety..........................................................................................................................................86
4.5.1. Labeling................................................................................................................................................86
4.5.2. Wire Safety...........................................................................................................................................87
4.5.3. Equipment and System Grounding.....................................................................................................87
4.5.4. Clearances/Physical Awareness...........................................................................................................87
5. Components.................................................................................................. 89
5.1. Panels..........................................................................................................................................91
5.2. Disconnects................................................................................................................................95
5.3. Charge controllers......................................................................................................................99
5.3.1. No controller.........................................................................................................................................99
5.3.2. Voltage regulator................................................................................................................................100
5.3.3. Basic charge controller with a low voltage disconnect (LVD)...........................................................100
5.3.4. Pulse Width Modulation (PWM) controller ......................................................................................101
5.3.5. Maximum Power Point Tracking (MPPT) controller......................................................................102
5.3.6. Charge controller comparisons..........................................................................................................103
5.3.7. Displays...............................................................................................................................................104
5.4. Batteries....................................................................................................................................105
5.4.1. No battery............................................................................................................................................107
5.4.2. Lead acid batteries..............................................................................................................................109
5.4.3. Lithium batteries.................................................................................................................................110
5.4.4. Dangers................................................................................................................................................111
5.5. DC Loads.................................................................................................................................112
5.6. Inverters...................................................................................................................................114
5.6.1. No inverter...........................................................................................................................................115
5.6.2. Modified sine wave..............................................................................................................................116
5.6.3. True (or pure) sine wave......................................................................................................................116
5.6.4. Grid tied...............................................................................................................................................117
5.7. AC Loads..................................................................................................................................118
5.8. Wires and plugs........................................................................................................................118
5.8.1. Insulation............................................................................................................................................120
5.8.2. Color...................................................................................................................................................120
5.9. Additional safety devices..........................................................................................................123
5.10. Racking..................................................................................................................................124
vi
5.10.1. Basics of Racking...............................................................................................................................124
5.10.2. Installation angle...............................................................................................................................125
5.10.3. Types of DIY Racking......................................................................................................................125
5.10.4. 3D Printed Racking..........................................................................................................................128
5.10.5. After market Building Integrated PV (BIPV) Racking...................................................................130
5.11. Monitoring..............................................................................................................................131
5.12. Systems...................................................................................................................................131
6. Sizing a system with no batteries....................................................................143
6.1. Simple DC load........................................................................................................................143
6.2. Load with a voltage regulator..................................................................................................146
7. Sizing a system with batteries........................................................................149
7.1. Needs assessment (aka energy audit).........................................................................................150
7.2. Sizing Batteries.........................................................................................................................153
7.2.1. Battery Bank........................................................................................................................................156
7.3. Sizing Panels ............................................................................................................................158
7.3.1. Photovoltaic array................................................................................................................................162
7.3.2. Photovoltaic array specification ..........................................................................................................163
7.4. Sizing Charge Controller.........................................................................................................164
7.4.1. Charge Controller Array Current and Voltage.................................................................................164
7.4.2. Charge Controller Load Current.......................................................................................................165
7.5. Sizing Inverter..........................................................................................................................167
7.6. Sizing Wires and Plugs.............................................................................................................168
7.7. Sizing Disconnects....................................................................................................................170
8. Other useful stuff .........................................................................................171
8.1. Using old panels.......................................................................................................................171
8.2. Units related to electricity........................................................................................................172
8.3. Economics ...............................................................................................................................174
8.3.1. Cost of disposable battery per kWh....................................................................................................174
8.3.2. Levelized cost of electricity..................................................................................................................175
8.3.3. Back of the Envelope Method.............................................................................................................175
8.3.4. Spreadsheet Method............................................................................................................................176
8.3.5. SAM Method......................................................................................................................................179
8.4. Disclaimer................................................................................................................................181
vii
8.5. Problem sets ............................................................................................................................182
8.6. Example systems and online community.................................................................................182
9. Index...........................................................................................................185
10. Author bios.................................................................................................193
10.1. Joshua Pearce..........................................................................................................................193
10.2. Lonny Grafman.....................................................................................................................194
viii
Foreword
To Catch the Sun is a precious collection of story and knowledge that is both practically
accessible, and intellectually rich. Lonny sets the framework for the technical knowledge
by sharing his journey in practice, often with humbling lessons learned along the way.
This open and very relatable honesty is an opportunity for readers to learn critical lessons
that are often only learned via personal relationship and experience. The ‘Solar Stories’
clearly share the intimate human aspect of this work, and the vital importance of taking
the time to profoundly listen, observe and, if you are not a part of the community of solar
application, serve the work so that your involvement is no longer needed in the end.
The technical knowledge, especially from Joshua’s lab, that follows the stories is laid out
to give the reader a remarkable depth of understanding in relatively few pages, again
with wonderful insight and experience shared throughout. I have never seen a book
designed to share the technical knowledge of practical application dive so beautifully
into the science of photovoltaics! Each section explores the components, design, financial
and safety considerations while offering consistent troubleshooting advice and examples
from the field. To Catch the Sun is a unique gift for those seeking autonomous solar power
for their families and communities!
Dr. PennElys Droz has worked for over 20 years in service
of the re-development of thriving, ecologically, culturally and
economically sustainable and resilient Indigenous Nations,
primarily through the Indigenous organization Sustainable
Nations and most recently, within NDN Collective.
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