Bifacial performance ratio

Similar to performance ratio except it accounts for the additional rear side irradiance in the denominator, weighted by the module’s bifaciality coefficient.

Output name

Bifacial performance ratio

Symbol

PR_bifi

Units

-

Formula

$$\frac{E_{out}\mathrm{/}{P}_0}{(H_{POA,f}+\phi \cdot H_{POA,r})\mathrm{/}{G}_{i,\text{ref}}}$$

Where $\phi$ is the bifaciality coefficient of the module (typically at STC), representing the ratio between the rear-side and front-side I-V characteristics.

Version history

In SunSolve versions prior to 7.30.1, the bifaciality coefficient was not applied to the rear-side irradiance. The equation was:

$\begin{array}{r}{\displaystyle P{R}_{\text{bifi}}=\frac{E_{out}\mathrm{/}{P}_0}{(H_{POA,f}+H_{POA,r})\mathrm{/}{G}_{i,\text{ref}}}}\end{array}$

This has been corrected to properly weight the rear-side contribution by the module’s actual bifacial performance.