Energy Validation Against PVsyst

Input data:

• Latitude, Longitude = 31.785, -106.495

• Time Zone = - 7

• Weather data

  El Paso, United States SolarAnywhere Typical GHI Year Lat_31_785 Lon_-106_495 SA format (H).csv

• Inverter: 1 units Sungrow SG3600UD

• ILR = 1.1

• Row to Row = 20 ft

• Layout: https://app.solar-prod.pvfarm.io/1867

   

PVFARM Result I

Taking into account:

• Shading

• Incidence angle (IAM) losses

• Soiling losses

• Bifaciality

• Thermal losses

• Spectral correction

• Module quality losses

• Mismatch losses

• DC ohmic wiring losses

• Inverter loss during Efficiently

• Inverter loss during over/under inverter voltage and current

• Inverter loss due to overpower

For Solar Module: 7 209 units LR5-72HBD-550M we get:

Produced Energy: 9 454 MWh/year

Specific Production: 2 384 Wh/W/year

Performance Ratio: 80.59 %

 

 

PVsyst Result I

Taking into account the same factors:

For Solar Module: 7 209 units LR5-72HBD-550M we get:

Produced Energy: 9 487 MWh/year

Specific Production: 2 393 Wh/W/year

Performance Ratio: 80.01 %

 

 

Error PVFARM vs PVsyst < 1%

 

 

PVFARM Result II

For Solar Module: 8 232 units FirstSolar FS-6480A we get:

Produced Energy: 8 894 MWh/year

Specific Production: 2 251 Wh/W/year

Performance Ratio: 76.03 %

 

PVsyst Result II

Taking into account the same factors:

For Solar Module: 8 232 units FirstSolar FS-6480A we get:

Produced Energy: 9 231 MWh/year

Specific Production: 2 336 Wh/W/year

Performance Ratio: 78.2 %

Error PV Farm vs PVsyst = 3.6%

 

 

Note: This difference is mainly due to temperature losses because PVsyst calculates the dependence of power on temperature using its own empirical methodology. PVsyst can obtain a power temperature coefficient different from the manufacturer's specification.

 

 

PVFARM directly uses the temperature coefficient of power from the manufacturer's specifications to calculate power versus temperature.

 

 

 

PVFARM vs PVsyst

When taking into account additional important factors in PVsyst (they are not in PVFARM):

• Electrical Losses due Shadings

• AC ohmic wiring losses

• Transformer loss

For Solar Module LR5-72HBD-550M we get:

 

PVFARM Result (the same as Result I)

Produced Energy: 9 454 MWh/year

Specific Production: 2 384 Wh/W/year

Performance Ratio: 80.59 %

 

PVsyst Result

Produced Energy: 8 982 MWh/year

Specific Production: 2 265 Wh/W/year

Performance Ratio: 75.90 %

 

Error PVFARM vs PVsyst = 5.3%

Note: Electrical Loss due to shading makes the greatest contribution to losses. We carried out calculations in Pvsyst Electrical Losses due to shading using “Detailed calculation, according to Module Layout”. This option can be used for Layouts no larger than 5MW. But it gives a more accurate result compared to the "According to module strings" option. The "According to module strings" option does not take into account the connection of submodules via bypass diodes and gives an overestimated loss value.