Rear-side contribution to reference yield

The rear-side contribution to reference yield represents the increase in reference yield (irradiation resource) attributable to rear-side irradiation collection, weighted by the module bifaciality coefficient. This is an irradiation-based metric that does NOT include electrical or thermal losses.

A daily normalised version is also reported as Rear-side contribution to reference yield (daily normalised).

Output name

Rear-side contribution to reference yield

Symbol

G_bifi

Units

kWh⋅kWp^-1

Formula

$$\begin{array}{rl}{\displaystyle }& {\displaystyle \phantom{=}{Y}_{r,bifi}-Y_r}\\ {\displaystyle }& {\displaystyle =\frac{\phi \cdot H_{POA,r}}{G_{i,\text{ref}}}}\end{array}$$

Where:

• $Y_{r,bifi}$ is the bifacial reference yield (kWh/kWp)
• $Y_r$ is the standard reference yield (front-side only, kWh/kWp)
• $\phi$ is the module bifaciality coefficient (typically 0.70-0.85)
• $H_{POA,r}$ is the rear-side plane-of-array irradiation (kWh/m²)
• $G_{i,\text{ref}}$ is the reference irradiance (1000 W/m² or 1 kW/m²)
• $N_d$ is the number of days in the simulation period