[Hard] How much gain do you get by using bifacial modules?

[kandersolar]

Bifacial PV modules have a transparent backsheet and cells designed to collect light from both directions, meaning both the front- and rear-side irradiance contributes to system production. Therefore, simulation of bifacial PV systems requires a model to predict the irradiance on the rear side of the module in addition to the typical front-side models.

pvlib provides two rearside irradiance models: pvfactors and infinite_sheds.

How much of an increase in total (front+rear) irradiance do you get by using a bifacial module over an analogous monofacial module?

Follow-up questions:

• How much difference is there between the two models implemented in pvlib?
• Does the bifacial gain depend on system parameters like racking height or row spacing?

Useful links:

• https://pvlib-python.readthedocs.io/en/stable/gallery/index.html#bifacial-modeling
• https://pvlib-python.readthedocs.io/en/stable/user_guide/bifacial.html