Solar systems design I
Eng / Abd Elraheem Mohamed Ahmed
Off grid –system design
Eng/ Abd Elraheem Mohamed Ahmed
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Project
• Design off grid system has loads:
load
Power(watt)
Quantity
Total power(watt)
Hours of
operation
lamps
14
4
56
10
560
Fan
75
1
75
12
900
TV
100
1
100
5
500
Receiver
50
1
50
5
250
Refrigerator
300
1
300
8
2400
Mobile charger
25
1
25
2
50
total
606
Eng/ Abd Elraheem Mohamed Ahmed
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Energy(watt.hour)
4660
Step one
“panels sizing”
Eng/ Abd Elraheem Mohamed Ahmed
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• Total panels power = Pt =
• System efficiency : .75
total requried energy
P.S.H ∗η
; P.S.H = 5 hours
4660 watt. hour
Pt =
= 1242 𝑤𝑎𝑡𝑡
.75 ∗ 5 hour
Eng/ Abd Elraheem Mohamed Ahmed
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• Number of panels =
Pt
Pmax of single panel
=
1242
330
=3.76 ( 4 panels)
Eng/ Abd Elraheem Mohamed Ahmed
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Eng/ Abd Elraheem Mohamed Ahmed
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Step-two
“inverter sizing”
Eng/ Abd Elraheem Mohamed Ahmed
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• Inverter power = 1.3 * total power of loads
• Inverter power = 1.3 * 606 = 787.8 watt
Eng/ Abd Elraheem Mohamed Ahmed
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Step-three
“batteries sizing”
Eng/ Abd Elraheem Mohamed Ahmed
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• Total A.H of batteries =
Energy ∗ A.D
DoD ∗ Bus voltage
• A.D : autonomy days : 2 ; DOD : .7
• Bus voltage : according to inverter :
• Total A.H of batteries =
4660 ∗2
.7 ∗24
= 555 A. H
Eng/ Abd Elraheem Mohamed Ahmed
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Eng/ Abd Elraheem Mohamed Ahmed
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• No of parallel branches =
Total A.H
A.H of singel battery
• No of batteries in branch =
=
555
94
Bus voltage
single voltage of battery
• Total number of batteries = 6*2 = 12 batteries
Eng/ Abd Elraheem Mohamed Ahmed
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≅ 6 branches
=
24
12
= 2 𝑏𝑎𝑡𝑖𝑟𝑖𝑒𝑠
Step-four
“solar charger sizing”
Eng/ Abd Elraheem Mohamed Ahmed
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• charger current =
Total power of panels
Bus voltage
=
4∗330
24
Eng/ Abd Elraheem Mohamed Ahmed
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= 55 A
Eng/ Abd Elraheem Mohamed Ahmed
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Eng/ Abd Elraheem Mohamed Ahmed
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Components of system
• panels ( 4*330 watt )
• Inverter (800 VA )
• Solar charger (60 A)
• Batteries 12V (12 * C20 102 AH )
Eng/ Abd Elraheem Mohamed Ahmed
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connections
Eng/ Abd Elraheem Mohamed Ahmed
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Calculation of area
Eng/ Abd Elraheem Mohamed Ahmed
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Eng/ Abd Elraheem Mohamed Ahmed
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sun
L
∝
∅
x
Eng/ Abd Elraheem Mohamed Ahmed
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Eng/ Abd Elraheem Mohamed Ahmed
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