Review of Lecture 8
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Contents of lecture 9
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Solar hot water systems
C al
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Maximum solar concentration
a
G /Th ion
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Methods for©concentration
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Nontracking
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Solar Hot Water Systems
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J =1000 W/m
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http://78.136.49.147/images/Solar%20Hot%20Water%20Heating
%20Diagram.gif
Image by EERE.
Flat Panel Solar Hot Water Heaters
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h lt
C
a
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Ga /The ion
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h
g
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Images removed due to copyright restrictions.
Please also see:
http://greennav.files.wordpress.com/2008/03/solar-panel.gif
http://www.mdelectric.ca/1_Pictures/Green
Energies/GE-ViessmannCollector.jpg
http://collector-solar.com/products/index.htm
Photo by szczel on Flickr.
Figure by MIT OpenCourseWare.
2
Evacuated Tube Technology
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a
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Images removed due to copyright restrictions. Please see:
http://img.diytrade.com/cdimg/194777/1624552/0/1160536024/AllGlass_Evacuated_Solar_Collector_Tube-SFVA.jpg
http://img.diytrade.com/cdimg/194777/1624568/0/1160536058/AllGlass_Evacuated_Solar_Collector_Tube-SFVB.jpg
http://img.diytrade.com/cdimg/194777/1624573/0/1160536136/MetalGlass_Evacuated_Solar_Collector_Tube-SFVC.jpg
http://www.diytrade.com/china/4/products/1716424/All-Glass_Evacuated_Solar_Collector_Tube-SFVA.html
Vacuum Tube Hot Water HeatersT
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Images removed due to copyright restrictions. Please see any photos of solar water heaters, such as:
http://image.made-in-china.com/2f0j00ferESMmCAVoH/Solar-Collector.jpg
http://image.made-in-china.com/2f0j00VBdtYnQhIaRE/Split-Pressurized-SolarWater-Heater-CY-SP-24-.jpg
3
Efficiency Estimation---Evacuated Tubes
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Incoming Solar Radiation
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t
Qin =
Do • L • JCs h al
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AbsorbedaSolar
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Estimated and Experimental Results
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http://www.enviro-friendly.com/images/NSWWinter-Solar-Efficiency-graph.jpg
Courtesy of Hills Solar. Used with permission.
5
Total Renewable Capacity in 2007
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Courtesy of IEA-SHC. Used with permission.
Weiss et al., Solar Heat Worldwide, 2009 Ed.
Solar Heat Utilization
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Courtesy of IEA-SHC. Used with permission.
Weiss et al., Solar Heat Worldwide, 2009 Ed.
6
Earth
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an
Image by Robert Simmon (NASA).
Sun
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1.27 x 107 m
7900 mi
109 m
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1.39 x
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32'
Solar constant
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{ al
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1011
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m
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C
la ver
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March equinox
Mar 20/21
June solstice
Jun 21/22
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July 4
152,100,000 km
Sun
147,300,000 km
Perihelion
January 3
December
solstice
Dec 21/22
1.7%
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Sept 22/23
Figure by MIT OpenCourseWare.
Figure by MIT OpenCourseWare.
Maximum Concentration
of Sun Light---2nd Law Limit
Energy Balance
θs
r
R
G
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ht Sola
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4eπr 2 J sn= 4πR 2 J e
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4
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C
max
J
⎛R⎞
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s =
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Maximum Concentration
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e
c
2
max
2
Image removed due to copyright restrictions
Please see Fig. 1a in Gleckman, Philip, Joseph
O'Gallagher, and Roland Winston. "Concentration of
Sunlight to Solar-surface Levels Using Non-imaging Optics."
Nature 339 (1989): 198-200.
Gleckman et al., Nature, 339, 198 (1989)
θs
Gθas
θs
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focusing
mirror
r
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=
=
d
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Figure by MIT OpenCourseWare.
3D Concentration
Cmax =
1
4sin 2 θ s
Cmax =
1
= 107
2sin θ s
8
Imaging Concentration to Cylinder
T
,
θsn
e
o
t
h
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1/π sin θ
(1/π) C
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s
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Figure by MIT OpenCourseWare.
From Fig.4.3: R. Winston et al., Nonimaging Optics, Elsevier, 2005
Nonimaging Optics
T
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2D Concentration
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h
C+ ABa' =l A' B
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AC
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i
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Maximum when θ=θ
String Method
C
Edge ray Wave front W
θ
A'
A
Reflector profile
B'
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Figure by MIT OpenCourseWare.
3D Concentration
C =⎜
⎟
⎝
sin θ ⎠
s
9
2D Concentration to Cylinder
IT
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Winston and Hinterberger, Solar
Energy, 17, 255 (1975)
Courtesy of Elsevier, Inc., http://www.sciencedirect.com.
Used with permission.
23.5o (22-24.5 o)
g
yri
p
Co D
7
7
.99 2.99
r
Equator
Winter
Summer
Images from Wikimedia Commons,
http://commons.wikimedia.org
Earth Orbital
10
Daily Insolation Variation
IT
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Js
s
s
45o North Latitude
http://www.eoearth.org/article/Daily_a
nd_annual_cycles_of_temperature
Courtesy of Michael Pidwirny. Used with permission.
Q= JsAsinθ
Tracking
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J
C al
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θ
a
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t olar ers
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v
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9
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E
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tri Axis: Axis Along South-North Direction
Fo cOne
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s
s
s
11
V-Trough
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C
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• East-West Orientation, with
seasonal adjustment: 2.5-3
times
• South-North tracking
Holland, Solar Energy, 13, 149 (1971)
http://www.electricksolutions.com/cms/temp
lates/electriksolutions/IMAGES/banner1.jpg
Courtesy of Elsevier, Inc., http://www.sciencedirect.com.
Used with permission.
Solar Thermal Energy Conversion
---Mechanical Systems
T
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h
C al
g
n er m
a
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t olar ers
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o
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Images by EERE. Please also see Fig. 21-13 in Kreith, Frank, and D.
Yogi Goswami. Handbook of Energy Efficiency and Renewable Energy.
Boca Raton, FL: CRC Press, 2007.
Handbook of Energy Efficiency and Renewable Energy
12
Solar Trough
IT
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C
g r ma
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Ga /The ion
t © olar ers
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o
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9
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9
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Courtesy of Plataforma Solar de Almería. Used with permission.
Solar Trough
T
I
,M
n
e to
h
C al
g
n er m
a
G /Th ion
©
t olar ers
h
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C
o
C D rgy
7 97 ne
9
9
2. r 2.9 cal E
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Image removed due to copyright restrictions.
Please see Fig. 5.16 in Kaltschmitt, Martin, Wolfgang Streicher, and Andreas Weise.
Renewable Energy: Technology, Economics, and Environment. New York, NY: Springer, 2007.
Also see any photo of a commercial HCE, such as Schott's PTR 70.
13
Solar Trough with
Molten Salt Storage
IT
M
n, o
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h lt
C
g r ma
n
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h
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o
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9
9
9
9
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Courtesy of Elsevier, Inc., http://www.sciencedirect.com. Used with permission.
Price, H. Lupfert, E.“Advances in Parabolic Trough Solar Power Technology”
T
I
,M
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h
C al
g
n er m
a
G /Th ion
©
t olar ers
h
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C
o
C D rgy
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9
9
2. r 2.9 cal E
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From J. Karni
Ele
Photos by EERE, Sandia National Labs.
Image removed due to copyright restrictions.
Please see any photo of a linear Fresnel lens
system, such as http://commons.wikimedia.
org/wiki/File:Fresnel_reflectors_ausra.jpg
http://i.i.com.com/cnwk.1d/i/ne/p/2007/910
Ausra1_550x367.jpg
Courtesy of Jacob Karni. Used with permission.
14
Solar Trough: Concentration Ratio
IT
M
n, o
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h lt
C
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t © olar ers
h
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9
9
9
9
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Table removed due to copyright restrictions.
Please see Table 2 in Price, Hank, et al.
"Advances in Parabolic Trough Solar Power Technology."
Journal of Solar Energy Engineering 124 (May 2002): 109-125.
Price, H. Lupfert, E.“Advances in Parabolic Trough Solar Power Technology”
Solar Trough: Cost
T
I
,M
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C al
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a
G /Th ion
©
t olar ers
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o
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7 97 ne
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9
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Table removed due to copyright restrictions.
Please see Table 8 in Price, Hank, et al.
"Advances in Parabolic Trough Solar Power Technology."
Journal of Solar Energy Engineering 124 (May 2002): 109-125.
Price, H. Lupfert, E.“Advances in Parabolic Trough Solar Power Technology”
15
Trough Efficiency
IT
M
n, o
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h lt
C
g r ma
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Ga /The ion
t © olar ers
h
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C
o
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9
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9
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“Assessment of Parabolic Trough and Power Tower Solar Technology Cost and Performance Forecasts” NREL, 2003
Trough Cost Breakdown
T
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“Assessment of Parabolic Trough and Power Tower Solar Technology Cost and Performance Forecasts” NREL, 2003
16
Heliostat / Power Tower
T
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a
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Photo by Koza1983 on Wikipedia.
T
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©
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9
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Images by EERE and Sandia National Laboratory.
Courtesy of Jacob Karni. Used with permission.
From J. Karni
17
Heliostat Receiver
IT
M
n, o
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C
g r ma
n
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t © olar ers
h
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C
o
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9
9
9
9
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Images removed due to copyright restrictions.
Please see Fig. 21-49. 21-51, and Table 21-9 in Kreith, Frank, and D.
Yogi Goswami. Handbook of Energy Efficiency and Renewable Energy.
Boca Raton, FL: CRC Press, 2007.
Handbook of Energy Efficiency and Renewable Energy
Heliostat / Power Tower Cost
T
I
,M
n
e to
h
C al
g
n er m
a
G /Th ion
©
t olar ers
h
rig ct S onv
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o
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9
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Image removed due to copyright restrictions.
Please see Fig. 21-40 in Kreith, Frank, and D. Yogi Goswami.
Handbook of Energy Efficiency and Renewable Energy.
Boca Raton, FL: CRC Press, 2007.
Handbook of Energy Efficiency and Renewable Energy
18
Heliostat / Power Tower Efficiency
IT
M
n, o
e
h lt
C
g r ma
n
Ga /The ion
t © olar ers
h
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o
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“Assessment of Parabolic Trough and Power Tower Solar Technology Cost and Performance Forecasts” NREL, 2003
Dish
T
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h
C al
g
n er m
a
G /Th ion
©
t olar ers
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o
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Photo from Wikimedia Commons, http://commons.wikimedia.org
19
Dish and Stirling Engine
IT
M
n, o
e
h lt
C
g r ma
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t © olar ers
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o
y
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9
9
9
9
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Images removed due to copyright restrictions.
Please see Fig. 5.20, 5.21, and 5.22 in Kaltschmitt, Martin, Wolfgang Streicher,
and Andreas Weise. Renewable Energy: Technology,
Economics, and Environment. New York, NY: Springer, 2007.
Kaltschmitt, M.,Wolfgang, S. Wiese, A. “Renewable Energy, technology, Economics and Enviroment”
Dish and Stirling Engine
T
I
,M
n
e to
h
C al
g
n er m
a
G /Th ion
©
t olar ers
h
rig ct S onv
y
p ire
C
o
C
D rgy
7 97 ne
9
9
2. r 2.
9 cal E
Fo ctri
Ele
Table removed due to copyright restrictions.
Please see Table 5.10 in Kaltschmitt, Martin, Wolfgang Streicher,
and Andreas Weise. Renewable Energy: Technology, Economics,
and Environment. New York, NY: Springer, 2007.
Kaltschmitt, M.,Wolfgang, S. Wiese, A. “Renewable Energy, technology, Economics and Enviroment”
20
EM Waves
IT
M
n, o
e
h Fieldl t
E --- Electric
Maxwell Equations:
C
a
H ---gMagnetic Field
m
r
n
e Displacement
aDB ------ Electric
∂B
h
Magnetic
Induction
n
G
∇ × E = −
TFree Current
o
/
i
--Density
J
r
©
s
∂t
t ola er
h
v
ig t S • Constitutive
∂D
n
r
Relations
o
y
+ Je
∇ ×
H =
c
C
e
∂t op
D = ε E
C Dir rgy
7= ρ e 97 ne
∇ •D
9
B = μH
9
2. r 2.9 cal E
ε – Electric Permitivity
∇ •FBo= 0 tri
μ – Magnetic permeability
c
e
l
E
e
EM Wave Propagation inside A Medium
T
I
M
,
n
E
e to
h
•
Plane Wave Solution
C al
g
n ⎡erm⎛ N ˆ ⎞⎤
k
a
E(r,G
t ) = E o exp
Th⎢⎢⎣−siωio⎜⎜⎝ tn− co k • r ⎟⎟⎠⎥⎥⎦
/
r
©
H
ht Sola ve⎡ r
g
i
yr ecHt (r, t )C= Honexp⎢−
iω
⎛⎜⎜ t −
cN k̂ • r ⎞⎟⎟⎤⎥
p
⎝
⎠⎦
o ir
⎣
y
ω--- angular frequency
C
g
D
r
k --- Wavevector
7 97 n•ePoynting Vector (Energy Flux)
9
9
. Wavevector
. 9 al E
k̂ ---2Unit
2
1
r ric
S (r ) = Re[E × H ]
4πκ
o
α=
N=n+iκ,
t
2
F
c
λ
Complex refractive
index
Ele coefficient S = 1 n e E k̂
κ --- Extinction
o
o
*
−αx
2 μco
o
2
Absorption
Coefficient
21
EM Wave Reflection and
Transmission at An Interface
IT
M
• Snell Law n,
h e l to
θC
=θ
a
g n sinrm
n
θ = n sin θ
Ga /Th1 e ioi n 2 t
s
ar erCoefficients
t © •olFresnel
h
rig ct S or n=vE = − n cosθ + n cosθ
y
p ire
C E n cosθ + n cosθ
Symbol Convention: o
y
C D rg
E
2n cos θ
Field Going Out of Paper
7
t =
=
7 ne
Field9Going Into9Paper
E
n cos θ + n cos θ
9 of Incidence:
E
l
2.9 Inrthe2.Plane
E-Field
a
c
i
TM Wave
= // Wave
= p Wave
o
r
t of Incidence: • Reflectivity/transmissivity
F cPlane
H-Field In the
Re( N cos θ )
t
τ =
R =r
Ele
Ei
kr
n̂
Hi
ki
θi
x
θr
Er
i
n1
r
x
n2
Et
θt
kt
z
// r
2
i
1
t
//
// i
2
i
// t
//
// i
TE Wave = Wave = s Wave
t
1
2
i
2
//
1
i
1
2
//
//
t
2
t
Re( N1 cos θ i )
//
Examples
T
I
,M
n
e to
h
C al
g
n er m
a
G /Th ion
©
t olar ers
h
rig ct S onv
y
p ire
C
o
C D rgy
7 97 ne
9
9
2. r 2.9 cal E
tri as a function of the angle of incidence for a
FoReflectivity
c
le material with n=4 and for gold with N=10.8+i51.6.
Edielectric
Gold (wavelength=10um, TE)
1
Gold (wavelength=10um, TM)
REFLECTIVITY
0.8
Dielectric material (n=4, TE)
0.6
0.4
0.2
Dielectric material (n=4, TM)
Brewster
Angle
0
0
20
40
60
INCIDENT ANGLE
80
22
MIT OpenCourseWare
http://ocw.mit.edu
2.997 Direct Solar/Thermal to Electrical Energy Conversion Technologies
Fall 2009
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