Alternative Energy Technologies: An Introduction with Computer Simulations

302 Pages·2014·11.45 MB·English

by  Gavin Buxton

Energy B
U
X
T
O
N
Alternative Energy Technologies
An Introduction with Computer Simulations
Alternative energy sources are becoming increasingly important in
a world striving for energy independence, clean air, and a reprieve
from global warming. Solar cells, wind power, and biofuels are A
L
some of the competing alternative energy sources hoping to gain a
T
foothold in our future energy mix, and the economic advantages of
E
these technologies are continually increasing as costs are reduced R
and efficiencies increased. N
A
Alternative Energy Technologies: An Introduction with T
Computer Simulations explores the science and engineering I
V
behind a number of emerging alternative energy technologies,
E
including polymer solar cells, algae biofuels, and artificial leaves.

It also addresses the environmental need for these technologies. E
N
However, unlike its predecessors, this book employs simple
E
computer models implemented within spreadsheet environments
R
to simulate different aspects of the alternative energy technologies
G
and therefore teach the subject matter.
Y

This unique approach: T
E
• Provides a dual introduction to alternative energy technologies
C
and computer simulation H
• Elucidates the fundamental behaviors and complex interactions N
within the alternative energy systems O
• Makes computer simulation straightforward and accessible to L Alternative Energy
readers with no prior programming experience O
G
Featuring investigative exercises that deepen understanding I
E
and inspire further research, Alternative Energy Technologies:
S
An Introduction with Computer Simulations makes an ideal Technologies
introductory textbook for undergraduate students and a valuable
professional reference for experimental researchers.
An Introduction with Computer Simulations
K22086
Gavin Buxton
Alternative Energy
Technologies
K22086_FM.indd 1 11/7/14 1:22 PM
Nano and Energy
Series Editor: Sohail Anwar
PUBLISHED TITLES
Alternative Energy Technologies: An Introduction with
Computer Simulations
Gavin Buxton
Advanced Nanoelectronics
Razali Ismail, Mohammad Taghi Ahmadi, and Sohail Anwar
Computational Nanotechnology: Modeling and Applications with
MATLAB®
Sarhan M. Musa
Nanotechnology: Business Applications and Commercialization
Sherron Sparks
Nanotechnology: Ethical and Social Implications
Ahmed S. Khan
K22086_FM.indd 2 11/7/14 1:22 PM
Alternative Energy
Technologies
An Introduction with Computer Simulations
Gavin Buxton
ROBERT MORRIS UNIVERSITY
MOON TOWNSHIP, PA, USA
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
K22086_FM.indd 3 11/7/14 1:22 PM
CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742
© 2015 by Taylor & Francis Group, LLC
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
Version Date: 20141028
International Standard Book Number-13: 978-1-4822-1704-9 (eBook - PDF)
This book contains information obtained from authentic and highly regarded sources. Reasonable
efforts have been made to publish reliable data and information, but the author and publisher cannot
assume responsibility for the validity of all materials or the consequences of their use. The authors and
publishers have attempted to trace the copyright holders of all material reproduced in this publication
and apologize to copyright holders if permission to publish in this form has not been obtained. If any
copyright material has not been acknowledged please write and let us know so we may rectify in any
future reprint.
Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced,
transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or
hereafter invented, including photocopying, microfilming, and recording, or in any information stor-
age or retrieval system, without written permission from the publishers.
For permission to photocopy or use material electronically from this work, please access www.copy-
right.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222
Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that pro-
vides licenses and registration for a variety of users. For organizations that have been granted a photo-
copy license by the CCC, a separate system of payment has been arranged.
Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are
used only for identification and explanation without intent to infringe.
Visit the Taylor & Francis Web site at
http://www.taylorandfrancis.com
and the CRC Press Web site at
http://www.crcpress.com
Contents
1 Introduction to Alternative Energy Sources 1
1.1 Global Warming . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 Solar Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.4 Wind Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.5 Biofuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.6 Hydrogen Production and Fuel Cells . . . . . . . . . . . . . . 25
2 Introduction to Computer Modeling 31
2.1 Brief History of Computer Simulations . . . . . . . . . . . . 31
2.2 Motivation and Applications of Computer Models . . . . . . 32
2.3 Using Spreadsheets for Simulations . . . . . . . . . . . . . . 34
2.4 Typing Equations into Spreadsheets . . . . . . . . . . . . . . 35
2.5 Functions Available in Spreadsheets . . . . . . . . . . . . . . 37
2.6 Random Numbers . . . . . . . . . . . . . . . . . . . . . . . . 40
2.7 Plotting Data . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.8 Macros and Scripts . . . . . . . . . . . . . . . . . . . . . . . 41
2.9 Interpolation and Extrapolation . . . . . . . . . . . . . . . . 43
2.10 Numerical Integration and Differentiation . . . . . . . . . . . 46
2.11 Solving Linear Systems . . . . . . . . . . . . . . . . . . . . . 52
2.12 Non-linear Equations . . . . . . . . . . . . . . . . . . . . . . 55
2.13 Monte Carlo Simulations . . . . . . . . . . . . . . . . . . . . 55
2.14 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3 Global Warming and Pollution 75
3.1 Global Warming: Global Energy Balance Model . . . . . . . 76
3.2 Global Warming: Zonal Energy Balance Model . . . . . . . . 79
3.3 Global Warming: Radiative Model of a Cloud . . . . . . . . 86
3.4 Pollution: Gradient Transport Theory . . . . . . . . . . . . . 90
3.5 Pollution: Gaussian Plume Model . . . . . . . . . . . . . . . 100
3.6 Pollution: Gaussian Plume Model with Settling of Pollutants 107
3.7 Pollution: Gaussian Plume Model with Deposition of Pollutants 109
3.8 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
v
vi Contents
4 Solar Cells 121
4.1 Equivalent Circuit of Solar Cells . . . . . . . . . . . . . . . . 122
4.2 Drift-Diffusion Model of Photovoltaics . . . . . . . . . . . . . 129
4.3 Drift-Diffusion Model: Polymer Solar Cells . . . . . . . . . . 132
4.4 Drift-Diffusion Model: Nonuniform Exciton Dissociation . . . 140
4.5 Monte Carlo Model of Photovoltaics . . . . . . . . . . . . . . 146
4.6 Finite-Difference Time-Domain of Solar Cells Optics . . . . . 163
4.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
5 Wind Power 175
5.1 Betz Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
5.2 Blade Element Momentum Model . . . . . . . . . . . . . . . 180
5.3 Wake Models . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
5.4 Elastic Deformation of a Wind Turbine Blade . . . . . . . . 200
5.5 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
6 Biofuels 211
6.1 Droop Model . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
6.2 Photosynthetic Factory of Algae Growth . . . . . . . . . . . 218
6.3 Cellular Automata Model of Wood Combustion . . . . . . . 225
6.4 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
7 Hydrogen Production and Fuel Cells 237
7.1 Photovoltaic and Electrochemical Equivalent Circuit Model . 240
7.2 Simple Electrochemical Model of Fuel Cells . . . . . . . . . . 248
7.3 Continuum Mathematical Model of Fuel Cells . . . . . . . . 250
7.4 Fluid Dynamics and the Lattice Boltzmann Model . . . . . . 260
7.5 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
Index 285
Preface
Alternative energy sources are becoming increasingly important in a world
striving for energy independence, clean air, and a reprieve from global warm-
ing.Solarcells,windpower,andbiofuelsaresomeofthecompetingalternative
energy sources hoping to gain a foothold in our future energy mix, and the
economic advantages of these technologies are continually increasing as costs
are reduced and efficiencies increased. This book introduces the basic science
behindawiderangeofalternativeenergytechnologies,albeitinauniqueway.
Alternative sources of energy are introduced through some simple computer
models which can be used to capture their behavior. Computers have perme-
ated throughout our entire way of life, and revolutionized scientific research,
opening up a whole new way in which we do science and engineering. This
booknotonlyintroducesthesciencebehindalternativeenergysources(aswell
as some of the environmental needs for alternative energy sources), but also
the role of computer simulations in elucidating the science of these systems.
In particular, simple models implemented within spreadsheet environments
are discussed which makes the simulations straightforward and accessible to
students with no prior programming experience. The computer models intro-
duced in this book could be taught as part of a regular class, used as a spring
board for student research, or used by researchers not familiar with computer
modelingtoexplorethepowerandversatilityofsimplecomputersimulations.
vii
TThhiiss ppaaggee iinntteennttiioonnaallllyy lleefftt bbllaannkk
List of Figures
2.1 Typing text into a spreadsheet. . . . . . . . . . . . . . . . . . 35
2.2 Enteringaseriesofnumbersbyclickinganddraggingthesmall
black box in the corner. . . . . . . . . . . . . . . . . . . . . . 36
2.3 Typing an equation into a spreadsheet. . . . . . . . . . . . . . 37
2.4 Copyingformulasacrossawiderangeofcellssuchthatthecells
which are referenced change also relative to the cell doing the
calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.5 Example of how a macro can iteratively update a counter. . . 42
2.6 Example of a simple linear interpolation. . . . . . . . . . . . . 44
2.7 Comparison between a simple linear interpolation (solid lines)
and the polynomial interpretation obtained using Lagranges’
classicalformula(dashedlines).Twocurvesareshowna)where
thecurveiswigglyandb)wherethecurveisrelativelystraight
but with a sudden discontinuity. . . . . . . . . . . . . . . . . 45
2.8 Comparison between the sine function and a Taylor series ap-
proximation (polynomial of degree 7) of the sine function. . . 47
2.9 Finite difference approximation using discrete points in space
to represent continuum derivatives. . . . . . . . . . . . . . . . 49
2.10 Spreadsheet implementation of finite difference approxima-
tions.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.11 Asinefunction,alongwithitsfirstandsecondderivatives.The
grid spacing is relatively coarse at 0.1. . . . . . . . . . . . . . 51
2.12 Illustration of how a continuum function can be integrated by
breaking the area under the curve into trapeziums. . . . . . . 52
2.13 Spreadsheet implementation of a simple Monte Carlo model. 58
2.14 Spreadsheet implementation of a simple Monte Carlo model
(continued). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
2.15 The transition from ordered phases to random dispersion is
depicted in a simple Monte Carlo model. . . . . . . . . . . . . 60
2.16 Plot of the number of sites in the left or right halves of the
simulation which contain 1’s as a function of the number of
MonteCarlosteps.Asthesystembecomesrandomizedanequal
number of 1’s will be found in both sides. . . . . . . . . . . . 61
2.17 Illustrationofhowonlylocalswapsarepermittedinadynamic
Monte Carlo model. . . . . . . . . . . . . . . . . . . . . . . . 62
ix