Racking and bifacial sections

Method

The rear model takes the collector width of the Racking tab as the slope length, and the height above ground, the transparent fraction of the module plane and the structure shading factor of the bifacial section.

The math

$$L = W_{coll},\quad h = h_{bif},\quad \tau = \tau_{bif},\quad f_s = f_{bif} \tag{1}$$

where

Symbol	Meaning	Unit
$L$	the slope length of a row	m
$W_{coll}$	the collector width of the Racking tab	m
$h$	the height above ground: the lower edge on a fixed rack, the axis on a tracker	m
$h_{bif}$	the height above ground of the bifacial section	m
$\tau$	the transparent fraction of the module plane	—
$\tau_{bif}$	the transparent fraction of the bifacial section	—
$f_s$	the structure shading factor of the rear	—
$f_{bif}$	the structure shading factor of the bifacial section	—

References

1. Marion et al. 2017, A practical irradiance model for bifacial PV modules, NREL/CP-5J00-67847

API

bifacial.geometry = racking

Symbols follow the symbol registry.