Bifacial modules on a flat white roof and microinverters

[Nader Shaheen]

Hello, I am attempting to create a model for (220) 530W bifacial modules utilizing APSystems QT2 microinverters and I'm having difficulty figuring out what I should input for detailed losses and how to reflect white roof's additional generation potential. Any suggestions what values to use for Thermal Parameter, Ohmic Losses, and Module Quality would be appreciated.

[dtarin]

This should be under 'How-to' or 'Simulations'

[Michele Oliosi]

Thanks @dtarin

@Nader Shaheen, regarding the white roof additional generation potential, you should define a higher albedo in your bifacial model definitions ("bifacial" button in the system window, appears once bifacial modules are selected).

Themal parameters won't change between bifacial and monofacial, you can use the presets to fit your case. For module quality you usually don't need to do anything but leave the default, unless you are using degraded modules. Finally ohmic losses just depends on your cabling. A more visual way is by defining cable lengths in the "detailed computation".

[Nader Shaheen]

What albedo amount should I use? 0.7 maybe?

[dtarin]

That could be too high, degradation of albedo will mostly occur in the first 2 months to 1 year, and level off after that. It will depend on your roof, materials, location, weather conditions (i.e. rainfall), whether the white roof is new or pre-existing, etc. Look for studies on the subject. 

Edited November 28, 2022 by dtarin