Adding multiple PV panels to one system
Hello everyone,
I am currently facing an issue while attempting to incorporate multiple PV panels into a system connected to a battery. The simulation appears to work correctly when I use only one panel. However, when I increase the number of panels, the overall output decreases significantly (for example, I obtain 306 kWh annually from a single panel, but only 169 kWh from three panels combined).
I would greatly appreciate any insights or suggestions regarding the potential reasons for this discrepancy. Below, I have provided the text format of the relevant part of the simulation for reference.
Best,
!- =========== ALL OBJECTS IN CLASS: GENERATOR:PHOTOVOLTAIC ===========
Generator:Photovoltaic,
PV_1, !- Name
PV_1_02a57cc9, !- Surface Name
PhotovoltaicPerformance:EquivalentOne-Diode, !- Photovoltaic Performance Object Type
Performance1, !- Module Performance Name
Decoupled, !- Heat Transfer Integration Mode
1, !- Number of Series Strings in Parallel {dimensionless}
1; !- Number of Modules in Series {dimensionless}
Generator:Photovoltaic,
PV_2, !- Name
PV_2_2934d52e, !- Surface Name
PhotovoltaicPerformance:EquivalentOne-Diode, !- Photovoltaic Performance Object Type
Performance2, !- Module Performance Name
Decoupled, !- Heat Transfer Integration Mode
1, !- Number of Series Strings in Parallel {dimensionless}
1; !- Number of Modules in Series {dimensionless}
Generator:Photovoltaic,
PV_3, !- Name
PV_3_b5c547e8, !- Surface Name
PhotovoltaicPerformance:EquivalentOne-Diode, !- Photovoltaic Performance Object Type
Performance3, !- Module Performance Name
Decoupled, !- Heat Transfer Integration Mode
1, !- Number of Series Strings in Parallel {dimensionless}
1; !- Number of Modules in Series {dimensionless}
!- =========== ALL OBJECTS IN CLASS: PHOTOVOLTAICPERFORMANCE:EQUIVALENTONE-DIODE ===========
PhotovoltaicPerformance:EquivalentOne-Diode,
Performance1, !- Name
CrystallineSilicon, !- Cell type
36, !- Number of Cells in Series {dimensionless}
2.892, !- Active Area {m2}
1, !- Transmittance Absorptance Product {dimensionless}
1.12, !- Semiconductor Bandgap {eV}
1000000, !- Shunt Resistance {ohms}
10.67, !- Short Circuit Current {A}
24.03, !- Open Circuit Voltage {V}
25, !- Reference Temperature {C}
1000, !- Reference Insolation {W/m2}
9.64, !- Module Current at Maximum Power {A}
20.75, !- Module Voltage at Maximum Power {V}
0.00512, !- Temperature Coefficient of Short Circuit Current {A/K}
-.06728, !- Temperature Coefficient of Open Circuit Voltage {V/K}
20, !- Nominal Operating Cell Temperature Test Ambient Temperature {C}
45, !- Nominal Operating Cell Temperature Test Cell Temperature {C}
800, !- Nominal Operating Cell Temperature Test Insolation {W/m2}
30, !- Module Heat Loss Coefficient {W/m2-K}
50000; !- Total Heat Capacity {J/m2-K}
PhotovoltaicPerformance:EquivalentOne-Diode,
Performance2, !- Name
CrystallineSilicon, !- Cell type
36, !- Number of Cells in Series {dimensionless}
2.892, !- Active Area {m2}
1, !- Transmittance Absorptance Product {dimensionless}
1.12, !- Semiconductor Bandgap {eV}
1000000, !- Shunt Resistance {ohms}
10.67, !- Short Circuit Current {A}
24.03, !- Open Circuit Voltage {V}
25, !- Reference Temperature {C}
1000, !- Reference Insolation {W/m2}
9.64, !- Module Current at Maximum Power {A}
20.75, !- Module Voltage at Maximum Power {V}
0.00512, !- Temperature Coefficient of Short Circuit Current {A/K}
-.06728, !- Temperature Coefficient of Open Circuit Voltage {V/K}
20, !- Nominal Operating Cell Temperature Test Ambient Temperature {C}
45, !- Nominal Operating Cell Temperature Test Cell Temperature {C}
800, !- Nominal Operating Cell Temperature Test Insolation {W/m2}
30, !- Module Heat Loss Coefficient {W/m2-K}
50000; !- Total Heat Capacity {J/m2-K}
PhotovoltaicPerformance:EquivalentOne-Diode,
Performance3, !- Name
CrystallineSilicon, !- Cell type
36, !- Number of Cells in Series {dimensionless}
2.892, !- Active Area {m2}
1, !- Transmittance ...
Have you tried reporting various
Output:Variables related to these objects to see where the two simulations differ?Thank you for your response.
I tried reporting Generator Produced DC Electricity Rate [W] for each panel, Electric Load Center Produced Electricity Rate [W] for total produced energy, and Facility Total Purchased Electricity Rate [W] to see the bought electricity. I'm not expecting exact multiplication in produced energy, however, 3 panels combined produce less annual energy than 1 panel.
I can increase the "Number of Modules in Series" and get the desired result but I need to obtain a similar result with an array of panels by adding to the Generators tab.
Thank you.