Bifacial system design

• Applying elevation from roof/surface
• Selecting surface reflectance (albedo factor)
• Checking the bifacial gain on the Derating table of the Reports page
• Formula used for calculating Isc BNPI current rating

Applying elevation from roof/surface

1. Go to the Balance of System section in the array designer

2. Set mounting type as tilt frame

3. Set the appropriate tilt angle

4. Set Elevation from surface in meters as required. This is the height between the surface and the bottom edge of the panel.

Selecting surface reflectance (albedo factor)

1. Go to the Solar & Battery designer section

2. Scroll down to the Derating section

3. Select the Surface Reflectance value (the albedo factor is mentioned in brackets)

Checking the bifacial gain on the Derating table of the Reports page

The bifacial gain is displayed in the Derating table of the Reports page (Designer view) as below:

Formula used for calculating Isc BNPI current rating

If the Isc BNPI is not stated on the module datasheet, the short-circuit current rating for bifacial panels is calculated as follows:

Isc BNPI = Isc STC *(1+0.135*BF), where BF is the bifaciality factor