-Solar cell -MPPT -Batteries -Structure of solar powered aircraft -Impulse solar aircraft

1. Solar
s
aircraftS
By Abolfazl Mazloom
November 2012

3. Why solar energy?
 Infinity
 Availability
 Inexpensive
 No pollution
 No preservation cost
 High power-to-weight ratio
 Easy to Product
 …

4. World Solar Energy Map
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5. Proportion of Utilization
Asia; 4%
• Six Countries hosting the
North America; 16%
majority of large
photovoltaic power plants:
 USA
 Italy
 Germany
 Spain
 Japan
 South Korea
Europe; 80%

6. Total Global PV Power
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 Fifth level

7. Dissection Solar
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8. THE BAND GAP
In solid state physics and related applied
fields, the band gap is the energy
difference between the top of the valence
band and the bottom of the conduction
band in insulators and semiconductors. It
is often spelt "band gap".

9. PV Technology Classification
● Poly Crystalline PV Cells
Amorphous Silicon PV Cells
Multi Crystalline PV Cells
Mono Crystalline PV Cells
Silicon
Thin Film
Crystalline
Technology
Technology
Mono Amorphous
Crystalline Silicon PV
PV Cells Cells
Multi Poly
Crystalline Crystalline
PV Cells PV Cells

10. Silicon Crystalline Technology
 Currently makes up 86% of PV market
 Very stable with module efficiencies 10-16%
Mono crystalline PV Cells
• Made using saw-cut from single
cylindrical crystal of Si
• Operating efficiency up to 15%
Multi Crystalline PV Cells
Click to edit Master text styles • Caste from ingot of
 Second level melted and recrystallised
Third level
silicon

 Fourth level
Fifth level
Cell efficiency ~12%

•
• Accounts for 90% of
crystalline Si market

11. Thin Film Technology
 Silicon deposited in a continuous on a base material such as glass,
metal or polymers
 Thin-film crystalline solar cell consists of layers about 10μm thick
compared with 200-300μm layers for crystalline silicon cells
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PROS
• Low cost substrate and  Second level
fabrication process  Third level
 Fourth level
CONS  Fifth level
• Not very stable

12. Amorphous Silicon PV Cells
 Operating efficiency ~6%
 Makes up about 13% of PV market
PROS Click to edit Master text styles
• Mature manufacturing
technologies available
 Second level
 Third level
CONS  Fourth level
• Initial 20-40% loss in  Fifth level
efficiency

13. Poly Crystalline PV Cells
Non – Silicon Based Technology
Copper Indium
High absorption coefficient
High efficiency levels
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PROS
 Third level
 Fourth level
• 18% laboratory efficiency  Fifth level
• >11% module efficiency
CONS
• Immature manufacturing
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process

14. Semiconductor Material Efficiencies
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15. Future Technologies
Ultra Thin Wafer Solar Cells
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 Thickness ~ 45μm
 Third level
 Cell Efficiency as high as 20.3%  Fourth level
 Fifth level
Anti- Reflection Coating
 Low cost deposition techniques use a
metal organic titanium or tantanum
mixed with suitable organic additives
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16. ‫‪Structure Solar Cells‬‬
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17. ‫دانشکده برق و کامپیوتر -‬
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18. Silicon Solar Cells
Si is first choice for solar cells
because for good knowledge of
Si processing in micro
electronics industry
Efficiency-
 26% theoretical.
 24.7% obtained in laboratory.
 12-16% commercial.
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19. Losses
Losses in Si solar cells, causes
efficiency to reduce. Resistive loss
Reflection losses. Reflection loss
Recombination Recombination
loss
losses.
Resistive losses.
Thermal losses.
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20. Primary Energy Collection Parameters
 latitude  Altitude (Cloudy , Humidity)
 Time of the year  Cell Temperature
 Time of the day  Cell Orientation
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21. High Efficiency Solar Cells
Solutions
 lightly phosphorus diffused emitters, to minimise recombination losses and
avoid the existence of a "dead layer" at the cell surface;
 closely spaced metal lines, to minimise emitter lateral resistive power losses;
 very fine metal lines, typically less than 20 µm wide, to minimise shading losses;
 small area devices and good metal conductivities, to minimise resistive losses in
the metal grid;
 use of elaborate metallization schemes, such as titanium/palladium/silver, that
give very low contact resistances;
 use of anti-reflection coatings, which can reduce surface reflection from 30% to
well below 10%;
…
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22. ‫‪V/I Curve‬‬
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23. Effect temperature on Solar Cells
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24. A Question?
How we must set Voltage and Current in
solar cell’s output for production maximum
power?
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25. Maximum Power Point Tracking
 a device is needed that finds the maximum power point (MPP)
and converts that voltage to a voltage equal to the system voltage.
 Maximum Power Point
Tracking , frequently
referred to as MPPT, is
an electronic system
that operates the
Photovoltaic (PV)
modules in a manner
that allows the modules
to produce all the
power they are capable
of.
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26. Structure A MPPT
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27. Solar panel set
 Maximum Continuous Power Output : 225W  DC Output Voltage: 250V
 Nominal Voltage : 240 V  Nominal Output Current : 0.9375 A
 Nominal Frequency : 60 Hz  Total Harmonic Distortion: < 5%
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28. Batteries
Several technologies are available and currently:
 Lithium polymer
 lithium-ion
 nickel-metal-hydride (NiMH)
 nickel-cadmium (NiCd)
 lead-acid
Lithium-ion (or lithium-ion-polymer where the electrolyte is a gel and not a
liquid) technology is the best concerning gravimetric energy density.
They have upper efficiency and less weight as compared to another batteries.
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29. Lithium Batteries evolution over the last years
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30. Solar Powered Aircraft
 Advantages
They haven’t any fuel tank; High Safety
Non require to refuel; Possible long term flight
Low speed; Gangling fight on a region
Lesser mechanical section; Lesser upkeep
 Environmentally friendly
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31. Require to Technology
lightweight composite structures
lightweight and low power avionics systems
high efficiency electric motors & batteries
thermal control systems for high altitude flight
high specific power solar array
stratospheric flight operations
fault tolerant flight control system
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32. communication system
Block diagram of typical solar powered AC
Batteries Solar Cells
MPPT Board
DC/DC Navigation
DC/AC Systems
X BOARD
Communication
To All Systems
Sections
Motor Driver Power
Line
Other
Motors Data
Systems
Line
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33. ‫‪Day & Night‬‬
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34. Altitude Flight
1) Fly at minimum night altitude
2) Climb
3) Cruise at max altitude; if power is available
4) Descent at idle power
5) Fly at minimum night altitude
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35. Losses
From solar energy to propeller ~ 89% losses!!
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36. History of solar flight
Solar Riser Sunseeker Pathfinder Solar-Impulse
70’s 80’s 90’s 2000’s
Solar Solair II Helius
Challenger
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37. ‫‪Solar Impulse‬‬
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38. Solar Impulse
 Objective:
Develop a manned solar powered aircraft
which can fly around the world with solar
power only
 Approach:
The goal for the Solar Impulse community
is to have this aircraft fly across the world one
day
 Consequence:
Fly for 26 hours; Nine of these hours were
during the night
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39. Specification
 Wingspan: 63,4m  Motor power: 4x10HP electric engines
 Length: 21.85m  Solar cells: 11628 (10748 on the
 Height:
wing, 880 on the horizontal stabilizer)
6.4m
 Average flying speed: 70 km/h
 Maximum altitude: 8500m  Take off speed: 35 km/h
 Weight: 1600Kg
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40. ‫‪Flight Altitude‬‬
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41. References
 solar cells- materials, manufacture and operation; by
Tom Markvart
 Design of Solar Powered Airplanes for Continuous
Flight; by André Noth
 http://www.wholesalesolar.com/solar-panels.html
 http://en.wikipedia.org/wiki/Solar_Cells
 http://en.wikipedia.org/wiki/Solar_Impulse
 http://www.solarimpulse.com/
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42. Thank you for attention