The document discusses the design parameters for a high altitude airship powered by solar energy. It determines that a thin film solar panel of 13.34 square meters could generate 40KW of power at an altitude of 60,000 feet, weighing only 9.5 kg. A 1.8 kg lithium-ion battery could store the required 40KWh of energy. A 20kW fuel cell weighing under 2 kg could regenerate power for 22 hours of each day. The overall specifications meet the goals of generating 40KW of power for 10-15 years while weighing less than the 135 lb payload capacity.

1. HIGH ALTITUDE AIRSHIP

2. Literature Review
• HALE-D HAA:
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Hull Vol: 50 000ft^3=>3,700,000ft^3
Length : 240ft=>500ft
Diameter: 70ft=>150ft
Propulsion motors:2 Kw Electric
Energy storage:40Kwh(Li-ion battery)
Solar Array:15Kw thin film
Station keeping altitude:60,000ft
Payload Weight:50lbs(23Kg)
Payload Power:
Life time>15days(Trail Target:90 days)
Reusable :Yes

3. FULL SCALE HAA
• With subsequent work being carried out the full scale
HAA is expected to function at quasi geo-synchronous
orbit for a period of 10 years.
• The Airship operates in the stratosphere just barely
within the outer limits of the earth's atmosphere.
• The geostationary position of 60,000 -70,000feet (1821 km) has been selected because there are minimal
wind conditions during a significant part of the year at
this altitude and the air density is only five percent of
that at the surface.

4. PARAMETER FINALISATION
• Parameters to be finalised:
PV Panel
1. PV panel area
2. PV panel weight
Battery Weight(Saft VL 6Ah Lithium-ion
battery)
URFC(Unitized Regenerative Fuel Cell)

5. PV Panel Area Calculation
• On ground:
Power
Area
1KW unit
8m-sq
30KW unit
240m-sq
40KW unit
320m-sq
• Solar flux increases significantly as we move to higher altitudes in earth’s
atmosphere.
• At at height of 60,000ft(18,000m):
Power
Area
0.03W unit
1cm-sq
3KW unit
1m-sq
40KW unit
13.34m-sq
50KW unit
16.67m-sq
With increased in altitude and use of thin film solar cell technology area of
solar panel required for a particular amount of power requirement can be
significantly reduced.

6. Calculation : Weight of PV panel
• Data from specification sheet of a solar
module(Data for solar panel used):
1. Dimension:306mm X 218mm X 25mm
2. Power=5Kw
3. Weight=1.00Kg
Vol. of solar panel=(306X218X25)/10^9 m^3
Density for a normal traditional solar
panel=1/vol=599.628Kg/m^3

7. Calculation : Weight of PV panel
• Range of thickness of thin film solar cell varies
from few nanometers to few micrometers i.e in
the orders of 10^(-9) to 10^(-6) much less than
25mm thickness in traditional PV panels.
• Normal PV density=599.628Kg/m^3
• Area of solar panel(to be used at
60000ft(=18Km):13.34m^2(16m^2)
 Considering the thickness of the thin film to be
maximum in orders of 10^-6(micrometers).
 Vol of solar panel:7.99 X 10^-3Kg(9.5 X 10^-3Kg)

8. Battery Weight Calculation
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Battery: Saft VL 6Ah Lithium-ion battery
Operating temp:25 degree Celcius
Power to weight ratio: 21370 W/kg
Rating:40Kw
Weight=(40000/21370)Kg=1.8kg

9. Operational Requirements for a 20Kw
RFC
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O/P Pow=20KW
Duration of discharge mode=1.25hrs
Required storage of energy=25KWh
Cycle efficiency=58%
Available time for charging=22.5h
I/P Pow during charging=1.9KW
Min. operational lifetime=15yrs
Total no. of charging cycles=1300

10. Operational Requirements for a 20Kw
RFC
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Total time in discharge mode=1300h
Total time in charge mode=23000h
Required quantity of hydrogen=1.18Kg
Required qty. of oxygen=9.36Kg
Hydrogen flow in discharge mode=7.8mol/min
Oxygen flow in discharge mode=3.9mol/min
Hydrogen flow in charge mode=0.43mol/min
Oxygen flow in charge mode=0.22mol/min

11. CONDITIONING CIRCUIT
REQUIREMENT?
• A power conditioner (also known as a line
conditioner or power line conditioner) is a
device intended to improve the quality of the
power that is delivered to electrical load
equipment.
• The term most often refers to a device that acts
in one or more ways to deliver a voltage of the
proper level and characteristics to enable load
equipment to function properly.

12. SOLAR PANEL
Working Principle : Thin Film Solar Cell

13. Advantages of Thin Film Solar Cell over
standard Solar Cells
• 1) Saves material and reduces the weight of Air
Ship,which is a major factor for airship performance.
• 2) Compare to traditional PV Cells ,thin film solar cell
can produce more amount of electrical power with the
same amount of area as they are based on mono
crystalline .
• 3) Cheaper than traditional panels
• 4) Easy to handle
• 5) More flexible than conventional solar cells
• 6) Available as thin wafer sheets

14. Overall Specifications
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Total Power Rating: 40KW
Area of PV panel : 13.34m-sq
o/p pow(URFC): 40KW
Operational lifetime: 10-15yrs
( with maintenance)
• Solar module o/p energy density:3KW/m-sq
• Payload Capacity:135lbs(63Kg)

15. CONCLUSION
• The parameters calculated for modeling of solar
powered airship seem to be in agreement with one
another.
• The total weight of the model is well below the
payload capacity .
i.e Weight(Battery+URFC+Solar Panels +Conditioning
Ckt.) < (Payload Capacity(135lb))