Chen C.J. Physics of Solar Energy
Подождите немного. Документ загружается.
i
i
“ChenSolarEnergy” — 2011/5/17 — 17:56 — page 320 — #347
i
i
i
i
i
i
320 Bibliography
[88] Renewable Energy World. Global concentrated solar power industry to reach 25
gw in 2020. REW, 2009.
[89] Q. C. Zhang. Recent progress in high-temperature solar-selective coatings. Solar
Energy Materials and Solar Cells, 62:63–74, 2000.
[90] Q. C. Zhang, Y. Yin, and D. R. Mills. High-efficiency M0-Al
2
O
3
cermet selective
surfaces for high-temperature application. Solar Energy Materials and Solar Cells,
40:43–53, 1996.
[91] J. Zhao, A. Wang, P. P. Altermatt, S. R. Wenham, and M. A. Green. 24% efficient
perl silicon solar cell: Recent improvements in high-efficiency silicon solar cell
rezsearch. Solar Energy Materials and Solar Cells, 41–42:87–99, 1996.
i
i
“ChenSolarEnergy” — 2011/5/17 — 20:45 — page 321 — #348
i
i
i
i
i
i
Index
absorptivity, 105
airmass, 110
alcohol, see ethanol
altitude, 78
AM, see airmass
AM1.5 solar spectral irradiance, 109
analemma, 102
antireflection coatings, 194–200
double-layer, 199
intuitive argument, 195
matrix method, 195
single-layer, 197
aphelion, 98
artificial photosynthesis, 219
ATP, 214
Auger recombination, 193
autumnal equinox, 84, 89, 93, 95, 103, 284
azimuth, 78
beam and diffuse solar radiation, 112
bilayer organic solar cells, 222
biodiesel, 16
oil palm, 16
biofuel, 14
alcohol, see ethanol
biodiesel, 16
Brazil, 14
ethanol, 14
biomass, 14
blackbody radiation, 52–58, 63–64, 183,
187, 189, 191, 209, 228, 230, 234
Einstein’s derivation, 63
Planck formula, 55
Rayleigh–Jeans law, 53
Stefan–Boltzmann’s law, 56
Bouguer–Lambert–Beer’s law, 107
building design, 273–285
building materials, 275–280
R-value, 276
U-value, 277
glazing, 280
heat transfer coefficient, 277
specific thermal resistance, 276
thermal mass, 278
thermal resistance, 276
burning mirrors, 225
C4 plants versus C3 plants, 216
Calvin cycle, 215
Carnot cycle, 123–126
ideal gas, 132
Carnot efficiency, 123, 133
celestial sphere, 78
altitude, 78
azimuth, 78
declination, 79
elevation, 78
equatorial system, 78
height, 78
horizon, 78
horizon system, 79
hour angle, 78
right ascension, 80
vernal equinox, 80
central receiver with heliostats, 244
chemical potential, 129
chlorophyll, 212
absorption spectrum, 213
HOMO, 213
LUMO, 213
coefficient of performance, 134
heat pump, 135
refrigerator, 135
concept of photons, 58–63
Einstein’s theory, 59
experimental verification, 61
wave–particle duality, 62
conduction band, 166
coordinate transformation, 81–84
Cartesian coordinates, 81
321
Physics of Solar Energy C. Julian Chen
Copyright © 2011 John Wiley & Sons, Inc.
i
i
“ChenSolarEnergy” — 2011/5/17 — 20:45 — page 322 — #349
i
i
i
i
i
i
322 Index
spherical trigonometry, 82
COP, see coefficient of performance
cosine formula, 290
crystalline silicon solar cells, 200
daily solar radiation, 93
Denmark, 13
detailed balance, 158
detailed-balance treatment, 186
direct solar radiation, 87
horizontal surface, 88
latitude tilt surface, 88
vertical surface, 88
dye-sensitized solar cells, 219
ecliptic, 84
electric cars, 269
energy consumption, 269
solar energy and, 269
electromagnetic waves, 43–47
elevation, 78
energy comsumption, 3
United States, 3
world, 3
energy conservation, 273–285
energy efficiency, 273–285
energy return on energy invested, 4
photovoltaics, 25
energy storage, 253–271
energy unit conversion, 287–288
Btu, 288
etajoule, 287
joule, 287
kilojoule, 287
kilowatt, 287
kilowatt-hour (kWh), 288
megajoule, 287
megawatt, 287
quad, 288
watt, 287
enthalpy, 128
entropy, 127
equation of time, 97, 100
from eccentricity, 99
from obliquity, 98
equator, 77
equatorial system, 78
EROI, see energy return on energy
invested
ethanol, 14
evacuated tube, 236
excess minority carriers, 172
lifetime, 173
fill factor, 24, 182
flat-plate collectors, 232
formula C, 292
fossil fuels, 2
depletion of, 3, 5–8
proved resources, 2
Francis turbine, 9
free electrons, 166
concentration, 166
diffusion coefficient, 166
free energy, 128
genetically engineered algae, 219
geothermal energy, 18–21
deep, 20
shallow, 18, 114–116, 133, 138
Gibbs free energy, 129
Golden Rule, 154
continuous spectrum, 157
discrete levels, 155
ground source heat pump
Carnot efficiency, 133
COP, 134
theory, 133
heat, 120
heat pump, 133
height, 78
high-pressure vacuum-tube collectors, 240
highest occupied molecular orbital, see
HOMO
holes, 166
concentration, 166
diffusion coefficient, 166
i
i
“ChenSolarEnergy” — 2011/5/17 — 20:45 — page 323 — #350
i
i
i
i
i
i
Index 323
holistic approach, 274
HOMO, 152
chlorophyll, 213
direcrt observation, 153
horizon, 78
hot box, 226
hour angle, 78
Hubbert peak, 5–8
Alaska, 8
derivation, 5
in the US, 7
hydroelectric power, 9
in various countries, 9
hydrogen atom, 147–149
energy levels, 148
quantum mechanics, 148, 300–302
ideal gas, 130
adiabatic process, 131
Carnot cycle, 132
constant-pressure specific heat, 131
constant-volume specific heat, 131
entropy, 130
equation of state, 130
internal energy, 130
isothermal process, 132
insolation, 111
integrated solar combined cycle, see ISCC
interaction of sunlight with atmosphere,
108
interaction of sunlight with Earth,
105–116
Kelvin-Helmholtz time scale, 70
Kirchhoff’s law, 106
latitude, 77
LFR, see linear Fresnel reflector
Li ion batteries, see lithium-ion batteries
linear fresnel reflector, 248
lithium-ion batteries, 266
CoO
2
, 266
electrochemistry, 266
LiFePO
4
, 266
MnO
2
, 266
resource of lithium, 268
longitude, 77
lowest unoccupied molecular orbital, see
LUMO
LUMO, 152, 219, 221, 222
chlorophyll, 213
direcrt observation, 153
maximum power, 182
Maxwell’s equations, 42
electromagnetic waves, 43
quantities in, 42
vector potential, 43
meridian, 77
Greenwich, 77
prime, 77
moral equivalence of war, 29–31
NADPH, 214
nature of solar radiation, 41–64
NE, see negative electrode
negative electrode, 264
lead–acid battery, 264
Li ion battery, 266
NiMH battery, 265
north pole, 77
obliquity, 84
oil palm, 16
open-circuit voltage, 180
optics of thin films, 47–49
origin of solar energy, 67–75
parabolic trough concentrator, 243
paraboloidal dish concentrator, 245
paraffin wax, 261
PCM, 257
encapsulation, 261
paraffin wax, 261
salt hydrates, 261
water–ice systems, 258
PE, see positive electrode
perihelion, 98
i
i
“ChenSolarEnergy” — 2011/5/17 — 20:45 — page 324 — #351
i
i
i
i
i
i
324 Index
phase transition material, see PCM
photoelectric effect, 58–63
and concept of photons, 59
Einstein’s theory, 59
experimental facts, 59
photosynthesis, 211
algae, 219
artificial, 219
ATP, 214
C4 versus C3, 216
Calvin cycle, 215
chlorophyll, 212
chloroplast, 216
efficiency, 217
NADPH, 214
power density, 217
photovoltaics, 21–24, 177–208
antireflection coatings, 194–200
Auger recombination, 193
average price, 23
bilayer organic solar cells, 222
birth of, 21
crystalline silicon solar cells, 200
design and processing, 202
dye-sensitized solar cells, 219
efficiency, 24
efficiency limit, 190
efficiency limit for AM1.5 radiation,
190
fill factor, 24, 182
grid parity, 35–39
installation, 37
materials, 179
maximum power, 182
nominal efficiency, 189
nonradiative recombination
processes, 191
open-circuit voltage, 180
peak watt, 25
price, 37
recombination time, 186
selenium, 177
semiconductor, 177–208
Shockley–Queisser limit, 183–191
short-circuit current, 180
silicon, 23, 177
solar cell equation, 180
surface-state recombination, 194
tandem solar cells, 207
thin-film solar cells, 204
trap-state recombination, 193
types, 25
pn-junction, 175
analysis, 170
depletion approximation, 168
effect of bias voltage, 171
excess minority carriers, 172
formation, 166
junction current, 172
quasi-Fermi levels, 170
Shockley equation, 173
space charge, 168
positive electrode, 264
lead–acid battery, 264
Li ion battery, 266
NiMH battery, 265
principle of detailed balance, 158
production of pure silicon, 201
quantum mechanics
algebraic approach of, 295–302
angular momentum, 297
basic concepts, 143
direct observation, 151
dynamic variables, 144
equation of motion, 145
harmonic oscillator, 295
hydrogen atom, 148, 300
interaction with radiation, 159
many-electron systems, 150
nanocrystal, 154
one-dimensional potential well, 146
single-electron approximation, 150
states, 143
transitions, 143–159
rechargeable batteries, 261–269
lead–acid batteries, 264
i
i
“ChenSolarEnergy” — 2011/5/17 — 20:45 — page 325 — #352
i
i
i
i
i
i
Index 325
lithium-ion batteries, 266
NiMH batteries, 265
reflectivity, 105
refractive index, 48–52
renewable energy, 3
geothermal, 3
hydropower, 3
wind, 3
wind power, 11
salt hydrates, 261
scanning tunneling microscope
schematic diagram, 152
seasons, 84
selective absorption surface, 228
semiconductor
photovoltaics, 177–208
solar cells, 177–208
semiconductors, 166
conduction band, 166
free electrons, 166
holes, 166
n-type, 166
p-type, 166
pn-junction, 161, 175
valence band, 166
Shockley equation, 173
Shockley–Queisser limit, 183–191
detailed-balance treatment, 186
efficiency limit, 190
for AM1.5 radiation, 190
nominal efficiency, 189
recombination time, 186
ultimate efficiency, 184
short-circuit current, 180
sine formula, 291
solar architecture, 274–275, 280–285
ancient China, 274
ancient Greece, 274
rural China, 275
solar cell design
module fabrication, 203
passivation and metal contacts, 202
PERL cells, 202
textured front surface, 203
solar cell equation, 180
solar cells, see photovoltaics
solar constant, 1, 67
solar electrochemistry, 211–223
photosynthesis, 211
solar energy, 1–39
economics of, 26–39
origin of, 67–75
total power, 1
solar heat collectors, 228–240
flat-plate, 232
high-pressure vacuum-tube, 240
selective absorption surface, 228
thermosiphon, 238
vacuum-tube, 236
solar igniter, 225
solar oven, 227
solar radiation, 41–64
wave theory, 41
solar terms, 94, 284
solar thermal energy, 225–249
solar thermal power systems, 242
central receiver, 244
LFR, 248
parabolic trough concentrator, 243
paraboloidal dish concentrator, 245
solar time, 84
solar water heater, 27–28, 31, 240
atop of White House, 30
China, in, 31
Day-and-Night, 28
early history of, 27
evacuated tubes, 33
pressurized, 241
thermosiphon solar heat collectors,
241
with a separate heat-exchange tank,
242
spherical triangle, 289
spherical trigonometry, 289–293
cosine formula, 290
formula C, 292
sine formula, 291
i
i
“ChenSolarEnergy” — 2011/5/17 — 20:45 — page 326 — #353
i
i
i
i
i
i
326 Index
spherical triangle, 289
standard time, 95
summer solstice, 84, 86, 94, 98, 101
Sun, 67–75
composition, 70
distance to Earth, 68
emission power, 69
energy source, 72
internal structure, 74
luminosity, 67
mass, 68
radius, 68
surface temperature, 69
sunrise time, 86
sunset time, 86
surface-state recombination, 194
tandem solar cells, 207
TCO, 205, 207, 222
in tandem solar cells, 207
in thin-film solar cells, 205
organic solar cells, 222
temperature, 120
thermodynamic, 120, 126
thermal energy storage, 253–261
phase transition, 257
sensible heat, 253
thermodynamics
first law of, 120
Joule’s experiment, 121
second law of, 123
thermodynamics of solar energy, 119–141
thermosiphon solar heat collectors, 238
thin-film solar cells, 204
amorphous silicon, 206
CdTe, 204
CIGS, 205
tracking sunlight, 77–102
transmittivity, 105
transparent conducting oxide, see TCO
trap-state recombination, 193
ultimate efficiency, 184
vacuum-tube collectors, 236
valence band, 166
vapor-compression refrigerator, 135
Carnot efficiency, 133
COP, 135
theory, 133
vernal equinox, 80, 84, 86, 89, 91, 93, 95,
96, 98, 101, 103, 284
water–ice systems, 258
wind power, 11
Betz limit, 11
Denmark, 13
efficiency, 11
winter solstice, 84, 86, 94, 98, 101
work, 120
i
i
“ChenSolarEnergy” — 2011/5/17 — 17:56 — page 314 — #341
i
i
i
i
i
i
314 List of Symbols
n
p
concentration of electrons in a p-region
n
p0
equilibrium concentration of electrons in a p-region
p
n
concentration of holes in an n-region
p
p
concentration of holes in a p-region
p
n0
equilibrium concentration of holes in an n-region
τ
n
lifetime of excess electrons in a p-region
τ
p
lifetime of excess holes in an n-region
D
n
diffusion coefficient of electrons
D
p
diffusion coefficient of holes
L
n
diffusion length of electrons
L
p
diffusion length of holes
Astromomy
S solar constant 1366 W/m
2
A
distance between the Sun and Earth 1.50 × 10
11
m
r
radius of the Sun 6.96 ×10
8
m
L
luminosity of the Sun 3.84 × 10
26
W
T
surface temperature of the Sun 5800 K
r
⊕
radius of the Earth 6378 m
φ latitude geographical coordinate
λ longitude geographical coordinate
h height also called altitude or elevation
A azimuth horizontal direction or bearing
δ declination angular distance to the equator
ω hour angle in radians, westward
ω
s
sunset hour angle in radians, always positive
ω
ew
east-west hour angle in radians, always positive
α right ascension absolute celestial coordinate
l mean ecliptic longitude on ecliptic plane
θ true ecliptic longitude on ecliptic plane
e eccentricity of orbit currently ≈ 0.0167
ε obliquity of ecliptic currently ≈ 23.44
◦
Thermodynamics
T temperature K
T
L
temperature of cold reservoir
T
H
temperature of hot reservoir
η efficeincy
i
i
“ChenSolarEnergy” — 2011/5/17 — 17:56 — page 288 — #315
i
i
i
i
i
i
288 Energy Unit Conversion
In microscopic physics, the electron-volt (eV) is often used as a unit of energy.
Because the charge of an electron is e =1.60 × 10
−19
C,1eV=1.60 × 10
−19
J.
Another unit frequently found in the literature is the calorie, abbreviated as cal. It is
defined as the energy required to raise the temperature of one gram of water by one
degree Celsius. Because at different temperatures the amount of energy required is
different, the definition of the unit is ambiguous. A well-defined and widely accepted
definition of the calorie is
1cal=4.184 J. (A.5)
One kilocalorie (kcal) is defined exactly as 4184 J. Therefore, unless necessary, SI units
are much preferred.
In the United States, the British thermal unit (Btu) is often used as the unit of
energy. It is defined as the energy to raise the temperature of one pound water by one
degree Fahrenheit. Similar to calorie, the exact value of the unit is ambiguous. The
International Table defines the Btu as 1055.06 J, which is very close to 1 kJ. In dealing
with renewable energy problems, we can take the approximation
1Btu≈ 1kJ. (A.6)
For large amounts of energy, a frequently used unit is the exajoule (EJ), which is
defined as 10
18
J. In the United States, the corresponding unit for large amounts of
energy is quadrillion Btu, abbreviated as quad, which is defined as 10
15
Btu. Because
1 Btu is very close to 1 kJ, for practical purposes, we can consider the two units to be
almost equivalent.
1quad≈ 1EJ. (A.7)
Another unit for large amounts of energy is terawatt-hour (TWh). It equals one billion
kilowatt-hours, or 0.0036 EJ. One terawatt-hour equals 3.6 × 10
15
J. One exajoule
equals 277.8 TWh.
In the utility industry, the gigawatt (GW) and terawatt (TW) are often used. One
gigawatt-year equals 3.156 × 10
16
J, roughly equals one 1/32 EJ. One terawatt-year
equals 3.156×10
19
J, roughly equals 32 EJ. In 2007, the world’s energy consumption of
energy is approximately 500 EJ, or an average power of 15 TW; the energy consumption
of the United States is approximately 100 EJ, or an average power of 3 TW. In 2008,
the energy consumption of the United States is slightly less than 100 EJ.
Several important approximate relations are worth noting:
• One barrier of crude oil is defined as 5.8 ×10
6
Btu.
• One cubic foot of natural gas is approximately 1000 Btu, or 1 MJ.
• One therm of natural gas is defined as 100,000 Btu, approximately 100 MJ.
• One kilojoule per mole is 0.01036 eV, approximately 10 meV.
• One kilocalorie per mole is 0.0434 eV.
i
i
“ChenSolarEnergy” — 2011/5/17 — 17:56 — page 289 — #316
i
i
i
i
i
i
Appendix B
Spherical Trigonometry
When we look into the sky, it seems that the Sun and all the stars are located on
a sphere of a large but unknown radius. In other words, the location of the Sun is
defined by a point on the celestial sphere. On the other hand, the surface of Earth is,
to a good approximation, a sphere. Any location on Earth can be defined by a point
on the terrestrial sphere;namelybythelatitude and the longitude. In both cases, we
are dealing with the geometry of spheres.
To study the location of the Sun with respect to a specific location on Earth, we
will correlate the coordinates of the location on the terrestrial sphere of Earth with
the location of the Sun on the celestial sphere. The mathematical tool of this study is
spherical trigonometry. In this Appendix, we will give a brief introduction to spherical
trigonometry, sufficient to deal with the problem of tracking the sunlight.
B.1 Spherical Triangle
A plane passing through the center of a sphere O cuts the surface in a circle, which is
called a great circle. For any two points A and B on the sphere, if the line AB does
not pass the center O, there is one and only one great circle which passes both points.
The angle
AOB, chosen as the one smaller than 180
◦
or π in radians, is defined as the
length of the arc AB. Given three points A, B,andC on the sphere, three great circles
can be defined. The three arcs AB, BC,andCA, each less than 180
◦
or π in radians,
form a spherical triangle; see Fig. B.1.
Following standard notation, we denote the sides BC, CA,andAB by c, b,anda,
respectively. The length of side a is defined as the angle
BOC, the length of side b is
defined as the angle
COA,andthelengthofsidec is defined as the angle
AOB.The
vertex angles of the triangle are defined in a similar manner: The vertex angle A is
defined as the angle between a straight line AD tangential to AB and another straight
line AE tangential to AC, and so on.
289
Physics of Solar Energy C. Julian Chen
Copyright © 2011 John Wiley & Sons, Inc.