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Renewable Energy System 402 Assignment 2
1 Satinderpal Singh (14413919)
Renewable Energy Systems 402
ASSINGMENT 2
Stand – Alone PV System
REPORTED BY:
SATINDERPAL SINGH (14413919)
DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
Renewable Energy System 402 Assignment 2
2 Satinderpal Singh (14413919)
Contents
INTRODUCTION .................................................................................................................................. 5
1. Preliminary Calculations ................................................................................................................. 6
1.1. Power Demand and Daily Energy Need of Farm.................................................................... 6
1.1.1. Steady – State Power demand ......................................................................................... 6
1.1.2. Surge Power demand ...................................................................................................... 6
1.1.3. Daily Energy requirement of the Farm house ................................................................. 7
1.2. Total DC Load and System Voltage ....................................................................................... 7
1.3. Insolation and PV array supply demand ................................................................................. 8
1.3.1. Insolation at the site ........................................................................................................ 8
1.3.2. PV array supply during worst month .............................................................................. 8
1.4. PV Sizing ................................................................................................................................ 9
1.4.1. Ah/day Produced from one string of PV ......................................................................... 9
1.4.2. Number of Parallel string ................................................................................................ 9
1.4.3. Number of Modules in One string .................................................................................. 9
1.4.4. AC output energy from designed PV array ................................................................... 10
1.5. Energy output and Load demand over 12 months of the year .............................................. 10
1.6. Annual load demand supplied by Designed PV system ........................................................ 12
1.7. Useable Storage required in the battery bank ....................................................................... 13
1.8. Total storage capacity of the battery ..................................................................................... 13
1.9. Minimum storage require to have discharge rate less than 5 hours ...................................... 13
1.10. Generator Sizing ............................................................................................................... 13
1.11. Annual energy Supplied by the Generator ........................................................................ 14
1.12. Schematic of Hybrid Power System ................................................................................. 14
2. Selection of Components .............................................................................................................. 15
2.1. Battery selection .................................................................................................................... 15
2.2. Inverter Charger Selection .................................................................................................... 16
2.3. Selecting Charger Controller ................................................................................................ 18
2.4. Selecting generator ................................................................................................................ 20
3. Performance of Designed System ................................................................................................. 21
3.1. Calculations using selected components values .................................................................... 21
3.2. System Costs ......................................................................................................................... 23
3.2.1. Capital Cost of the system ............................................................................................ 23
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3.2.2. Running Cost of the System .......................................................................................... 24
3.2.3. Cost of Electricity ......................................................................................................... 25
4. References ..................................................................................................................................... 26
List of Figures and Tables
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Figure 1: Steady - Power demand over 24 hours for the farm house ........................................ 6
Figure 2: Surge Power required over 24 hours for farm house ............................................................... 6
Figure 3: Insolation at the site during 12 months of the year .................................................................. 8
Figure 4: Connection diagram of the PV .............................................................................................. 10
Figure 5: Inverter energy output and Load demand over the 12 months of the year. ........................... 11
Figure 6: Schematic of standalone hybrid power system ...................................................................... 14
Figure 7: EXIDE 8RP670NX Battery bank configuration ................................................................... 16
Figure 8: Victron Energy 24/3000/70 inverter charger for the designed Standalone PV system ......... 18
Figure 9: Morningstar TS45 charge controller used for Stand - alone PV system ............................... 19
Figure 10: ABLE 2500W Petrol Generator for the designed standalone PV system ........................... 20
Table 1: Total energy demand of each equipment .................................................................................. 7
Table 2: Power output and Demand during different months of the year ............................................. 11
Table 3: Load energy required per month and energy Output per month of the designed PV system 12
Table 4: Comparing two batteries for the selection of required battery for the battery bank ............... 15
Table 5: Comparing two inverters for right selection of inverter ......................................................... 17
Table 6: comparing charger controllers for the selection...................................................................... 19
Table 7: Comparing two generators for the selection for the standalone PV system ........................... 20
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INTRODUCTION
Stand – alone PV systems are used where grid supply is not available. As compare to grid
connected PV system standalone PV systems are more complex and expensive because of
extra storage batteries required for the system. Although Stand – alone PV system are
expensive and complex but they are very useful in the providing energy in remote areas
where grid supply is not available because without grid electricity become more valuable.
The main part of the Stand – Alone PV system is PV array, charge controller, Battery bank,
inverter charge and Backup generator. Function of charger controller is to avoid over
charging and controlling the battery voltage. The voltage of the battery determines the system
voltage. Invert charger covert Dc power of battery to Ac power for the load and convert Ac
power from generator to DC power to charge batteries. Backup generator play important role
in providing energy when PV array is unable to meet the load requirement due to bad
insolation from the sun. Figure 6 shows the complete schematic diagram of the hybrid Stand
– alone PV system.
The purpose of this assignment is to design the stand – alone PV system for the remote area
farm house near Bridgetown, Western Australia. The main objective is to of the design is to
minimize the unit price produced from the system so that it is affordable for the customer.
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1. Preliminary Calculations
1.1. Power Demand and Daily Energy Need of Farm
1.1.1. Steady – State Power demand
Figure 1: Steady - Power demand over 24 hours for the farm house
From the plot of steady state power in figure 1 the maximum power demand is 1595 Watt at 6
PM.
1.1.2. Surge Power demand
Figure 2: Surge Power required over 24 hours for farm house
1595
0
200
400
600
800
1000
1200
1400
1600
1800
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Po
wer
(W
att
)
Hour of the Day
Total Steady - State Power over 24 hours
2250
0
500
1000
1500
2000
2500
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Po
we
r (W
att)
Hour of the Day
Surge Power Demand over 24 hours
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From the surge power plot over 24 hours in figure 1 the maximum surge power required is
2250 W at 8 AM.
1.1.3. Daily Energy requirement of the Farm house
Load Steady
– state
Power
(active)
(Watt)
Stand-
by
Power
(Watt)
Hours
of
Active
Mode
Active
Mode
Energy
(Wh/day)
Stand – by
Mode
Energy
(Wh/day)
Total Energy
For the
equipment
(Wh/day)
Lights 15*8
= 120
5 120*5
= 600
600
TV 150 4 3 150*3
= 450
4*(24 – 3)
= 84
450+84 = 534
Water Kettle 1000 0.25 1000*0.25
= 250
250
Washing
Machine
250 5 0.5 250 * 0.5
= 125
5*(24 – 05)
= 117.5
125+117.5 =
242.5
Laptop 20 3 3 20*3
= 60
3*(24 – 3)
= 63
60+63 = 123
Refrigerator 300 24 1300 1300
Table 1: Total energy demand of each equipment
Total energy requirement of the farm house = 600 + 534 +250 +242.5 + 123 + 1300
= 3049.5 Wh/day
1.2. Total DC Load and System Voltage
Total dc load = 𝑎𝑐 𝑙𝑜𝑎𝑑 (
𝑊ℎ
𝑑𝑎𝑦)
𝐼𝑛𝑣𝑒𝑟𝑡𝑒𝑟 𝑒𝑓𝑓𝑖𝑐𝑒𝑛𝑐𝑦=
3049.5
.90 = 3388.33 Wh/day
System voltage for the maximum power demand of 1595 W = 24 V
Total dc Load (Ah/day @ System Voltage of 24 V ) = 𝑇𝑜𝑡𝑎𝑙 𝑑𝑐 𝑙𝑜𝑎𝑑
𝑆𝑦𝑠𝑡𝑒𝑚 𝑣𝑜𝑙𝑡𝑎𝑔𝑒
= 3388.33
24 = 141.18 Ah/day
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1.3. Insolation and PV array supply demand
1.3.1. Insolation at the site
Figure 3: Insolation at the site during 12 months of the year
From the figure 3 the worst insolation is during month 6 (June). The insolation during month
6 = 2.3 KWh/m2/day
The peak – sun hours per day in month 6 = 2.3 hours/day
1.3.2. PV array supply during worst month
Design month solar percentage = 50%
Total load = 141.18 Ah/day
Energy require from PV each at invert input = Design solar percentage * Total load
= 141.18 * 0.50 = 70.6 Ah/day
2.3
0
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 10 11 12
Inso
lati
on
(K
Wh
/m2/d
ay
)
Month of the year
Insolation over 12 months
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1.4. PV Sizing
Rated Voltage of Scotty Poly 180 PV module (@ STC) (VR) = 36.3 V
Rated Current of Scotty Poly 180 PV module (@ STC) (IR) = 4.95 A
1.4.1. Ah/day Produced from one string of PV
Ah/day from one string of Scotty Poly 180 PV = Peak – Sun hour * IR * Coulomb
efficiency*Dirt and mismatch efficiency
Coulomb Efficiency of lead acid battery = 92%
Peak – sun hours during worst month = 2.3 Hours
Dirt and Mismatch efficiency = 93 %
Ah/day from one string = 2.3 * 4.95 * 0.92 * 0.93 = 9.741 Ah/day
1.4.2. Number of Parallel string
Number of parallel string = Supply required form the PV
Ah
day from one string
= 70.6
9.741= 7.24 ≈ 𝟕
Using 7 parallel string will over slightly under size the PV array.
1.4.3. Number of Modules in One string
Modules in series = System voltage / VR
= 24/36.3 = 0.6611 ≈ 1
As 0.6611 numbers of modules are not possible the modules per parallel string is 1.
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Figure 4: Connection diagram of the PV
1.4.4. AC output energy from designed PV array
PV array output during worst month = IR * Peak-Sun Hours * number of string * mismatch ef
= 4.95 * 2.3 * 7 * 0.93 = 74.116 Ah/day
Battery output = PV array output * Coulomb efficiency
= 74.116 * 0.92 = 68.19 Ah/day
AC power at inverter output = System voltage * Battery output * Inverter efficiency
= 24 * 68.19 * 0.90 = 1472.84 Wh/day
1.5. Energy output and Load demand over 12 months of the year
Peak sun hours during worst month (month 6) (Pw) = 2.3 Hours
Power at inverter output during worst month (month 6) (PW) = 1472.84 Wh/day
Power in any month N (PN) ∝ Peak – sun hours in month N (IN)
𝑃𝑁
𝐼𝑁=
𝑃𝑊
𝐼𝑊 ⟹
𝑃𝑁
𝐼𝑁=
1472.84
2.3
PN = 640.36 * IN Wh/day
N= 1,2,3,4,5,6,7,8,9,10,11,12.
Using above equation power output of the different month of the year can be calculated.
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Month Peak – Sun Hours
Inverter Energy
output
(Wh/day)
Load Demand
(Wh/day)
Jan 7.8 4994.85 3049.5
Feb 6.8 4354.48 3049.5
Mar 5.5 3522.01 3049.5
Apr 3.8 2433.39 3049.5
May 2.8 1793.02 3049.5
June 2.3 1472.84 3049.5
July 2.4 1536.88 3049.5
Aug 3.2 2049.17 3049.5
Sep 4.2 2689.53 3049.5
Oct 5.7 3650.08 3049.5
Nov 7 4482.56 3049.5
Dec 7.9 5058.89 3049.5
Table 2: Power output and Demand during different months of the year
Figure 5: Inverter energy output and Load demand over the 12 months of the year.
The energy generated during some months 10, 11, 12, 1, 2 is more than the energy demand
from the load and there is deficit in the energy during months 4,5,6,7, and 9.
0.00
1000.00
2000.00
3000.00
4000.00
5000.00
6000.00
1 2 3 4 5 6 7 8 9 10 11 12
Ene
rgy
(Wh
/day
)
Month of the year
Energy Output and Load Demand
Power output of System
Load Demand
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1.6. Annual load demand supplied by Designed PV system
From table 2 the load demand per month and Output power of the system per month can be
calculated by multiplying Wh/day with the number of days in the month.
Month
Energy
Generated by
the PV system
(KWh/month)
Energy demand
of load
(KWh/month)
Difference in
the energy
produced and
load demand
(KWh/month)
Load energy
Supplied by
the PV system
(KWh/month)
Jan 154.84 94.53 60.31 94.53
Feb 121.93 85.39 36.54 85.39
Mar 109.18 94.53 14.65 94.53
Apr 73.00 91.49 -18.48 73
May 55.58 94.53 -38.95 55.58
June 44.19 91.49 -47.30 44.19
July 47.64 94.53 -46.89 47.64
Aug 63.52 94.53 -31.01 63.52
Sep 80.69 91.49 -10.80 80.69
Oct 113.15 94.53 18.62 94.53
Nov 134.48 91.49 42.99 91.49
Dec 156.83 94.53 62.29 94.53
Total Energy (KWh/Year) 1113.07 919.62
Table 3: Load energy required per month and energy Output per month of the designed PV system
Negative difference in the energy produce and load demand means that there is deficit in the
energy. This deficit can be filled by the stand alone generator.
During the excess energy is wasted during months with positive difference between the
produced energy and load demand because storage unit is only designed to store energy
required for the load.
Annual Energy supplied by the designed PV system = 919.62 KWh/year
Annual energy demand of the load = 1113.07 KWh
Percentage of load demand supplied by the system = 919.62
1113.07 × 100 = 𝟖𝟐. 𝟔𝟐%
The annual deficit of the energy is 17.38 % which will be supplied by the stand alone
generator.
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1.7. Useable Storage required in the battery bank
Days of storage required for the battery bank = 3 days
Useable storage (Ah) = Total load (Ah/day) * Days of storage required
Useable storage = 141.18 * 3 = 423.54 Ah
1.8. Total storage capacity of the battery
Discharge Rate = 3 days = 72 hours
Minimum temperature at the site = - 5.1̊ C
Maximum depth of discharge (MDOD) = 80%
From above information (T, DR) = 100%
Total storage capacity of the battery = 𝑈𝑠𝑒𝑎𝑏𝑙𝑒 𝑠𝑡𝑜𝑟𝑎𝑔𝑒 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦 (𝐴ℎ)
𝑀𝐷𝑂𝐷 ×(𝑇,𝐷𝑅)=
423.54
.8 ×1
= 529.43 Ah
1.9. Minimum storage require to have discharge rate less than 5 hours
Minimum storage = 𝑀𝑎𝑥𝑖𝑚𝑢𝑚 𝑙𝑜𝑎𝑑 𝑝𝑜𝑤𝑒𝑟 ×5
𝑆𝑦𝑠𝑡𝑒𝑚 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 ×𝑀𝐷𝑂𝐷=
1557 ×5
24 × .80 = 414.36 Ah
The total storage capacity of the batter (529.43 Ah) is more than the required minimum
storage (414.36 Ah).
1.10. Generator Sizing
Charging time for the generator to charge battery bank = 10 hours
Inverter efficiency = 90%
Total storage capacity = 529.43 Ah
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System voltage = 24 V
Generator Size = 𝑇𝑜𝑡𝑎𝑙 𝑆𝑡𝑜𝑟𝑎𝑔𝑒 𝐶𝑝𝑎𝑐𝑖𝑡𝑦×𝑆𝑦𝑠𝑡𝑒𝑚 𝑉𝑜𝑙𝑡𝑎𝑔𝑒
𝐶ℎ𝑎𝑟𝑔𝑒 𝑡𝑖𝑚𝑒 ×𝑐ℎ𝑎𝑟𝑔𝑒𝑟 𝑒𝑓𝑓𝑖𝑐𝑒𝑛𝑐𝑦=
529.43 ×24
10 × 0.90
=1411.80 W
1.11. Annual energy Supplied by the Generator
Total load per annum = 1113.07 KWh/year
Annual energy produced by generator = (1 - % Energy supplied by the PV)*Total annual load
= (1 – 0.8262) * 1113.07 = 193.45 KWh/year
Percentage of energy supplied by the generator = (193.45/1113.07)*100 = 17.38 %
From table 3 total annual energy produced by the PV system can be calculated by adding the
generated power of each month generated by designed PV system.
Total energy produced by the PV system = 1155.03 KWh/year
Energy supplied to the load by the PV system = 919.62 Kwh/year
Energy wasted during a year = 1155.03 – 919.62 = 235.41 KWh/year
Percentage of energy wasted = (235.41/1113.07)*100 = 21.15 %
1.12. Schematic of Hybrid Power System
Figure 6: Schematic of standalone hybrid power system
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2. Selection of Components
2.1. Battery selection
Desired Rating for the Battery Bank
From the calculation in the part 1, desired values for the battery bank are:
Voltage of battery bank = 24 V
Total storage capacity required = 529.43 Ah
Depth of discharge for battery bank = 80%
Type of Battery = Lead – Acid battery
Most of the batteries available in the market are less than 24 V. The desire voltage of battery
banks with the minimum capacity of 529.43 Ah can be made by connected several batteries
in the series.
Comparing Batteries for Battery Bank
Reference [1] and [2] provides the source of data given the table 4.
Manufacturer EXIDE RAYLITE
Model 8RP670NX MIL 17S
Type of Battery Lead - Acid Lead - Acid
Voltage of Single battery 8 V 6 V
Storage capacity of single
battery @ 25̊ C 670 Ah 600 Ah
Number of cycles at 80%
Discharge depth 1500 Cycles 1500 Cycles
Number of batteries
required in series for
Battery Bank
24/8 = 3 Batteries 24/6 = 4 Batteries
Price of a battery $1,420 $ 1,156.41
Price of Battery bank 3 * $1420 = $4,260 4 * $1,156.41 = 4,625.64
Table 4: Comparing two batteries for the selection of required battery for the battery bank
From the table 4, both the batteries compare have enough storage required 529.43 Ah for the
designed system. The number of cycles for the life is same for both EXIDE and RAYLITE
batteries. To meet the system voltage 4 EXIDE batteries are require to be in series to build a
battery bank and if RAYLITE battery is considered then only 3 batteries are need to be in
series for the battery bank.
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From above reason it is clear that both batteries are technically compatible for the battery
bank of the system but the economically there is a significant difference in the cost of both
the batteries. The battery bank of EXIDE 8RP670NX cost $365.64 than the RAYLITE MIL
17S battery bank. As the main objective of the design is to minimize the unit price of energy
produced then EXIDE 8RP670NX is a good option to select for the system.
Selected battery for the Battery Bank = EXIDE 8RP670NX
Number of batteries in series = 3
Number of parallel strings = 1
Total storage of the battery bank = 670 Ah
Figure 7: EXIDE 8RP670NX Battery bank configuration
2.2. Inverter Charger Selection
Surge power required by the load = 750 + 1500 = 2250 W
Maximum steady state demand = 1557 W
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Desired Rating for the Battery Bank
Desire Inverter Characteristics
Continuous output power at 40̊ C = 1595 W
Input DC voltage = 24 V
Output AC voltage = 240 V
Output frequency = 50 Hz
Peak power = 1595 + 2250 = 3845 W
Efficiency = 90%
Desire Charger Characteristics
AC input voltage = 240 V
DC output voltage = 24 V
Nominal Current to battery for 10 hours charging = Battery storage / 10 = 524.9/10 = 52.49 A
Comparing Inverter Chargers
Reference [3] and [4] provides the source of data given the table 5.
Manufacturer Victron Energy SMA
Model 24/3000/70 SI2224
Inverter Characteristic
Continuous Output Power
@ 40̊ C 2200 W 1600 W
Input Dc Voltage 19 – 33V 16.8 – 31.5
Output Ac Voltage 230 V 202 – 253V
Output Frequency 50 Hz 50 Hz
Peak Power 6000 W 5000 W
Efficiency 94 % 93.6 %
Charger Characteristics
AC input voltage 187 – 265 V 172.5 – 250 V
DC Output Voltage 24 V 24 V
Rated current to battery 70 A 80 A
Price $2,972.20 $3,969.45
Table 5: Comparing two inverters for right selection of inverter
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Comparing Victor Energy 24/3000/70 and SMA S12224 inverter charger it is clear that both
inverters meet the technical desire requirement. Victron Energy 24/3000/70 inverter has
capacity of delivering steady – state power of 2200 W at maximum temperature at the site,
which is oversize than the required 1595 W. The other inverter charger in the comparison
SMA S12224 has a steady – state power rating very near to the required value. Both inverter
chargers can easily withstand the peak power due to surge and both have nearly equal
efficiency.
Although Victron Energy 24/300/70 inverter charger is oversized than the required rating but
it is still cheaper than SMA S12224. As we want to keep the cost low as possible it is good
option to select Victron Energy 24/300/70 and it easily meet the technical and safety
requirement of the system and high rating of power for Victron Energy 24/3000/70 allow
space for expansion to supply extra load in future.
Selected Inverter charger = Victron Energy 24/30/70
Figure 8: Victron Energy 24/3000/70 inverter charger for the designed Standalone PV system
2.3. Selecting Charger Controller
Rated current for the Schott poly 180 PV = 4.95 A
Number of Parallel strings of PV = 7
Voltage of PV array = 36.3 V
Desire Charger Characteristics
Solar input = 7 * 4.95 A = 34.65 A
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Load output = 34.65 A
System voltage = 24 V
Maximum solar input Voltage - >=36.3 V
Comparing Charger Controllers
Reference [5] and [6] provides the source of data given the table 6.
Manufacturer Morningstar Xantrex
Model TS45 C40
Solar Input Current 45 A 40 A
Output Current 45 A 40 A
System Voltage(Battery
Voltage) 12 -48 V 12 – 48 V
Maximum Solar Input
Voltage 125 V 125 V
Price $257.64 $ 275.62
Table 6: comparing charger controllers for the selection
Two charge controllers are compared in the table 6 for the selection purposes. Both Morning
stat TS45 and Xantrex C40 meet the desired technical requirements of the system. Both
inverters are capable at system voltage of 24 V and both can with stand the maximum solar
input of 36.3 V. Regarding current rating both chargers available in the market are oversize
than required 34.65 A current rating, TS45 have current rating of 45 A and C40 have 40 A
current rating. Technically it is better to select C40 because its current ratings are near to
desired rating.
Above reasons make Xantrex C40 a favourite for the selection but considering the cost of
both of the charger Morningstar TS45 is about $17.98 cheaper than C40. As our main aim of
the design is to keep the price of electricity low the selection of Morning TS45 will more
appropriate.
Selected charger controller = Morningstar TS45
Figure 9: Morningstar TS45 charge controller used for Stand - alone PV system
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2.4. Selecting generator
Desired Rating for the Generator
Output Power Rating = 1411.80 W
Output Voltage = 240 V
Frequency output = 50 Hz
Comparing Generators
Reference [7] and [8] provides the source of data given the table 7.
Manufacture Honda Able
Model Dunlite Petrol Generator
Output Voltage 240 V 240 W
Output Power 2000 W 25000 W
Fuel Unleaded Petrol Unleaded Petrol
Price $795 $499
Table 7: Comparing two generators for the selection for the standalone PV system
Table 7 shows that both compared generator meet the technical requirements for the system.
Both generators are rated higher than the required 1411.80 W. Honda Dunlite has a rating of
2000W and Able petrol generator have a rating of 2500 W. As both generators are technically
suitable for the system then cost of the generator will determine the selected generator. As
our objective is to design low cost selecting Able petrol generator will be a good choice
because it is $296 cheaper than Honda generator. As the rating of Able generator is higher it
will charger battery soon.
Selected generator = ABLE Petrol Generator
Figure 10: ABLE 2500W Petrol Generator for the designed standalone PV system
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3. Performance of Designed System
3.1. Calculations using selected components values
Efficiency of the inverter (Victoron Energy 24/30/70) = 94%
Total dc load = 𝑎𝑐 𝑙𝑜𝑎𝑑 (
𝑊ℎ
𝑑𝑎𝑦)
𝐼𝑛𝑣𝑒𝑟𝑡𝑒𝑟 𝑒𝑓𝑓𝑖𝑐𝑒𝑛𝑐𝑦=
3049.5
.94 = 3244.15 Wh/day
The total dc load of system has decreased to 3244.15 Wh/day from 3388.33 Wh/day due to
improve in the efficiency of the inverter from 90% to 94%.
New dc load in Ah/day = 3244.15
24 = 135.1729 Ah/day
Energy require from PV each at invert input = Design solar percentage * Total load
= 135.13 * 0.50 = 67.56 Ah/day
Number of parallel string = Supply required form the PV
Ah
day from one string
= 67.56
9.741= 6.93 ≈ 𝟕
In the calculations in the part 1 using 7 PV was under size but with the efficiency of victron
inverter efficiency t PV’s are perfect number for the system load required to be supplied
during worst moth of insolation.
AC output energy from designed PV array
PV array output during worst month = IR * Peak-Sun Hours * number of string * mismatch ef
= 4.95 * 2.3 * 7 * 0.93 = 74.116 Ah/day
Battery output of chosen EXIDE 8RP670NX = PV array output * Coulomb efficiency
= 74.116 * 0.92 = 68.19 Ah/day
Energy need to be supplied during worst month = 0.5 * Total load per day
= 0.5 * 3049.5 = 1524.75Wh/day
Renewable Energy System 402 Assignment 2
22 Satinderpal Singh (14413919)
AC power at inverter output = System voltage * Battery output * Inverter efficiency
= 24 * 68.19 * 0.94 = 1538.36 Wh/day
Above calculations shows that design system can easily meet the energy needed to be
supplied during worst month of insolation. As 1524.75 Wh/day is needed to be supplied
during worst month and design system is capable to supply 1538.36 Wh/day during worst
month of insolation.
Battery
Total storage battery required to store 3 days energy (preliminary calculations) = 529.43 Ah
Capacity of selected battery bank = 670 Ah > 529.43
Selected battery bank can store 3 days of load energy and even provide some extra storage to
supply for over load or surge power.
Generator
Power rating of selected Generator = 2500 W
Time to charge selected battery bank = 𝑇𝑜𝑡𝑎𝑙 𝑆𝑡𝑜𝑟𝑎𝑔𝑒 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦×𝑆𝑦𝑠𝑡𝑒𝑚 𝑉𝑜𝑙𝑡𝑎𝑔𝑒
𝐺𝑒𝑛𝑟𝑎𝑡𝑜𝑟 𝑠𝑖𝑧𝑒 ×𝑐ℎ𝑎𝑟𝑔𝑒𝑟 𝑒𝑓𝑓𝑖𝑐𝑒𝑛𝑐𝑦
= 529.43 ×24
2500 × 0.94 = 5.40 Hours
The selected Able petrol generator of 2500 W power rating will charge the selected battery
bank in 5.40 Hours.
Renewable Energy System 402 Assignment 2
23 Satinderpal Singh (14413919)
3.2. System Costs
3.2.1. Capital Cost of the system
PV Array Cost
Estimated cost of PV for per Watt [9] = $4/W
Rating of Schott Poly 180 PV = 180 W
Cost of one PV module = $4/w * 180 W = $720
Number of PV used for standalone system = 7
Total cost of PV array = $720 * 7 = $5040
Battery Bank Cost
Cost of one battery = $1,420
Number of batteries used in a battery bank = 3
Total cost of battery bank = 3 * $1420 = $4,260
Inverter Charger Cost = $2,972.20
Charge Controller cost = $257.64
Generator cost = $ 499
Installation + BOS Cost = 20% (PV $ + Battery bank $ + inverter $ +controller $+generator$)
= .20($5040 + $4260 + $2972.20 + $257.64 + $499)
=$2605.768
Capital Cost of the System = $5040 + $4260 + $2972.20 + $257.64 + $499 + $2605.768
= $15634.60
Renewable Energy System 402 Assignment 2
24 Satinderpal Singh (14413919)
3.2.2. Running Cost of the System
Generator Fuel Cost
Price of Generator electricity = $0.25/KWh
Annual energy produced of the generator = 193.45 KWh/Year
Annual running cost of the generator = 193.45 Kwh/year * $0.25/Kwh
= $48.3625/Year
Running cost of the generator over 25 years = $48.3625/year * 25 = $1209.06
Battery Maintenance Cost
Life of the battery bank = 9Years
Life of PV array = 25 Years
Number of battery bank require over 25 years = 25 / 9 = 2.77 ≈ 3
Number of replacement of battery bank required after installation = 3 – 1 =2
Cost of battery maintenance over the life time = 2 * battery bank cost
= 2 * $4260 = $8,520
Cost of maintenance of the battery per year = $8520/25 = $340.8/Year
Running cost of the system per year = $48.3625 + $340.8 = $389.162/year
Running cost over 25 Years = $1209.06 + $8520 = $9729.06
Renewable Energy System 402 Assignment 2
25 Satinderpal Singh (14413919)
3.2.3. Cost of Electricity
Energy supplied by the system per annum = $1113.07 KWh/year
Energy supplied by the system in 25 years = $1113.07 KWh/year * 25
Cost of energy = 𝐶𝑎𝑝𝑖𝑡𝑎𝑙 𝐶𝑜𝑠𝑡+𝑅𝑢𝑛𝑛𝑖𝑛𝑔 𝑐𝑜𝑠𝑡 𝑜𝑣𝑒𝑟 25 𝑌𝑒𝑎𝑟𝑠
𝐸𝑛𝑒𝑟𝑔𝑦 𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑 𝑏𝑦 𝑡ℎ𝑒 𝑠𝑦𝑠𝑡𝑒𝑚 𝑜𝑣𝑒𝑟 25 𝑦𝑒𝑎𝑟𝑠
= $ 15634.60+$9729.06
1113.07𝐾𝑊ℎ
𝑌𝑒𝑎𝑟 ×25 = $0.9115/KWh
Cost of energy produced by the system is $0.9115/KWh.
Renewable Energy System 402 Assignment 2
26 Satinderpal Singh (14413919)
4. References
[1] A. Energy. (2011, 26/.8/2012). Raylite Battery 6V 600Ah @ C100. Available:
http://www.apolloenergy.com.au/Renewable-Energy-Components/Raylite/MIL17S
[2] G. solar. (2011, 26/09/2012). Going solar Lead Acid batteries. Available:
http://www.goingsolar.com.au/pdf/catalogue/GS_11-12_batteries.pdf
[3] A. Energy. (2011, 27/09/2012). Sunny Island 2200W 24V 80 Inverter Charger.
Available: http://www.apolloenergy.com.au/Renewable-Energy-Components/Inverter-
Chargers/SI2224
[4] A. Energy. (2011, 27/09/2012). Victron 24V 3000W Inverter/Charger. Available:
http://www.apolloenergy.com.au/Renewable-Energy-Components/Inverter-
Chargers/MultiPlus-24-3000-70-16
[5] A. Energy. (2011, 27/09/2012). Morningstar Tristar 45A controller. Available:
http://www.apolloenergy.com.au/Renewable-Energy-Components/Regulators/TS45
[6] B. Directs. (2012, 27/09/2012). Xantrex C40. Available:
http://www.batteriesdirect.com.au/shop/product/12790/C40.html
[7] M. 4U. (2012, 27/09/2012). New honda camping genrator for sale - 2.5Kva Dunlite.
Available: http://www.machines4u.com.au/view/advert/2-5Kva-Dunlite/25183/
[8] Machines4U. (2012, 27/09/2012). New Able camping genrators for sale - PETROL
GENRATOR
Available: http://www.machines4u.com.au/view/advert/PETROL-GENERATOR-2-8KVA-
240VOLT/30726/
[9] G. M. Masters, Renewable and Efficient Electric Power Systems, 2004.