Introduction
System description
Schematic diagram for existing system
Existing system components
Parameters | Specification | Rating |
---|---|---|
Type of module | Polycrystalline | 1332 no. |
Individual power | Unit norm power | 255 Wp |
Array global power | Nominal (STC) | 339.6 kWp |
In series | 18 | |
No. of PV modules | In parallel (strings) | 74 |
Array operating characteristics (50 °C) | U mpp | 540 V |
I mpp | 8.28 A |
Parameters | Subjects | Rating |
---|---|---|
Input data | Recommended DC power | Greater than 157 kWp |
MPPT voltage range | 420–700 V DC | |
Input current | 375 A DC | |
Battery charging capacity | 200 A | |
Output data | Nominal output power | 300 kW (150 kW × 2) |
Nominal frequency | 50 Hz | |
Power factor | > 0.99 at full load | |
Voltage distortion at full load | < 3% | |
General data | Max power efficiency including transformer | > 96% |
MPPT efficiency | 99% | |
Internal consumption in operation | < 1% at full load |
Parameter | Specification | Rating |
---|---|---|
Type of battery | SOPzS tubular plated | 348 no. |
Individual capacity | Capacity at C10 rating | 1525 AH |
Voltage | Nominal voltage | 2 V |
In series | 174 | |
No. of batteries | In parallel | 2 |
General characteristics | Duty cycles at 50% DOD | 2500 |
Electrolyte | Sulphuric acid with density 1.24 kg/dm3 |
Schematic diagram of the proposed system
Proposed system components
Parameter | Specification | Rating |
---|---|---|
DC voltage regulator | DC/DC converter capable of power handling up to 50 kW | 6 no. |
DC fans and lights | 48 V energy-efficient DC fans and LED lights | Total capacity 175 kW |
Load profile
Existing system
Load description | Power (kW) |
---|---|
Fans and lights | 350 |
Air conditioners | 40 |
Water pumps | 27 |
Refrigeration | 8 |
Total | 425 |
Distribution of AC load | Power (kW) |
---|---|
AC load connected and powered by solar system | 280 |
AC load running on diesel genset | 145 |
Maximum AC load running on solar system at day time | 220 |
Maximum AC load running on solar system at night time | 60 |
Description | Hours |
---|---|
Daily load shedding (average) | 6 |
Daily sunshine hours available | 8 |
Daily grid usage | 10 |
Proposed system
Description | Power (kW) |
---|---|
Total rated load of the facility (after retrofitting AC appliances with DC) | 250 |
New lighting and fans load (DC) | 175 |
AC inductive load | 75 |
Load connected/shifted to solar system | 250 |
Load running on diesel genset | 0 |
Battery discharge behaviour
Existing system
Proposed system
System simulation
Existing system
Balances and main results | ||||||||
---|---|---|---|---|---|---|---|---|
GlobHor kWh/m2 | T Amb (°C) | Globlnc (kWh/m2) | GlobEff (kWh/m2) | EArray (MWh) | E_Grid (MWh) | EffArrR (%) | EffSysR (%) | |
January | 89.0 | 12.70 | 123.4 | 119.9 | 35.47 | 33.43 | 12.04 | 11.35 |
February | 111.0 | 15.00 | 142.4 | 138.6 | 39.80 | 37.55 | 11.71 | 11.05 |
March | 153.0 | 20.00 | 172.8 | 167.8 | 46.96 | 44.31 | 11.39 | 10.74 |
April | 167.0 | 26.10 | 169.4 | 164.3 | 44.28 | 41.76 | 10.95 | 10.33 |
May | 190.0 | 30.90 | 176.3 | 170.4 | 44.95 | 42.33 | 10.69 | 10.06 |
June | 191.0 | 33.30 | 170.4 | 164.5 | 43.00 | 40.49 | 10.57 | 9.95 |
July | 171.0 | 32.00 | 157.0 | 151.6 | 40.34 | 37.94 | 10.76 | 10.12 |
August | 172.0 | 31.10 | 167.1 | 161.8 | 42.84 | 40.37 | 10.74 | 10.12 |
September | 163.0 | 29.60 | 176.9 | 171.7 | 45.67 | 43.11 | 10.81 | 10.21 |
October | 130.0 | 25.20 | 158.1 | 153.5 | 42.40 | 40.01 | 11.24 | 10.61 |
November | 97.0 | 18.80 | 131.9 | 128.3 | 36.63 | 34.58 | 11.64 | 10.98 |
December | 86.0 | 14.20 | 126.4 | 122.8 | 35.74 | 33.68 | 11.84 | 11.16 |
Year | 1720.0 | 24.12 | 1872.2 | 1815.2 | 498.08 | 469.56 | 11.15 | 10.51 |
Proposed system
Atchison College Lahore | ||||||||
---|---|---|---|---|---|---|---|---|
Balances and main results | ||||||||
GlobHor (kWh/m2) | T Amb (°C) | Globlnc (KWh/m2) | GlobEff (kWh/m2) | EArray (MWh) | E_Grid (MWh) | EffArrR (%) | EffSysR (%) | |
January | 89.0 | 12.70 | 136.1 | 132.0 | 43.54 | 41.29 | 13.41 | 12.71 |
February | 111.0 | 15.00 | 154.7 | 150.0 | 48.63 | 46.13 | 13.17 | 12.49 |
March | 153.0 | 20.00 | 183.0 | 176.5 | 56.03 | 53.16 | 12.83 | 12.17 |
April | 167.0 | 26.10 | 175.2 | 168.3 | 51.70 | 49.02 | 12.36 | 11.72 |
May | 190.0 | 30.90 | 178.4 | 170.0 | 50.91 | 48.21 | 11.96 | 11.33 |
June | 191.0 | 33.30 | 170.8 | 162.3 | 48.08 | 45.52 | 11.80 | 11.17 |
July | 171.0 | 32.00 | 158.9 | 151.6 | 45.31 | 42.87 | 11.95 | 11.30 |
August | 172.0 | 31.10 | 171.2 | 163.9 | 49.20 | 46.64 | 12.04 | 11.41 |
September | 163.0 | 29.60 | 185.7 | 178.7 | 54.22 | 51.46 | 12.24 | 11.61 |
October | 130.0 | 25.20 | 170.0 | 164.4 | 51.26 | 48.65 | 12.63 | 11.99 |
November | 97.0 | 18.80 | 144.9 | 140.6 | 45.01 | 42.73 | 13.02 | 12.36 |
December | 86.0 | 14.20 | 140.6 | 136.5 | 44.52 | 42.22 | 13.26 | 12.58 |
Year | 1720.0 | 24.12 | 1969.5 | 1894.7 | 588.42 | 557.90 | 12.52 | 11.87 |
Results and discussion
Month | Horizontal global irradiation (kWh/m2) | Existing system | New system | ||
---|---|---|---|---|---|
PR | Energy (kWh) | PR | Energy (kWh) | ||
Jan | 88.99 | 79.52 | 33.43 | 87.99 | 41.29 |
Feb | 110.99 | 77.26 | 37.55 | 86.06 | 46.13 |
Mar | 152.87 | 75.23 | 44.31 | 83.99 | 53.16 |
Apr | 166.98 | 72.53 | 41.76 | 81.19 | 49.02 |
May | 190.03 | 70.95 | 42.33 | 79.27 | 48.21 |
Jun | 191.05 | 70.29 | 40.49 | 78.47 | 45.52 |
Jul | 170.97 | 71.57 | 37.94 | 79.56 | 42.87 |
Aug | 172.05 | 71.35 | 40.37 | 79.67 | 46.64 |
Sep | 163.09 | 71.77 | 43.11 | 80.37 | 51.46 |
Oct | 130.12 | 74.52 | 40.01 | 83.01 | 48.65 |
Nov | 97.01 | 77.08 | 34.58 | 85.54 | 42.73 |
Dec | 85.91 | 78.19 | 33.68 | 86.75 | 42.22 |
Total | 1720 kWh/m2 | 73.80% | 469.56 | 83.40% | 557.9 |