Hi all, working on a residential solar install in SoCal and considering bifacial panels. Came across bifacial solar options at decent prices and wondering if the rear yield is worth the cost premium. Anyone here installed bifacial on a south-facing residential roof? What kind of rear yield bonus did you actually see? Thanks!
I’ve found that bifacial panels do not make a measurable difference when mounted flat on a regular roof. And no real difference at all if the roof material is dark. However, they do seem to achieve a small increase when mounted on tilt frames with a very light-coloured roofing material. But this is not easy to quantify, and I don’t have any specific numbers (due to the many variations in temperature and irradiance).
The best application for bifacial panels, based on what they are designed for, is a ground mounted with a light coloured surface (light sand, rock, or snow) or mounted vertically or near vertical) in an east/west orientation so the morning light hits one side and the afternoon light on the other side (as shown in the attached photo).
Another benefit is that most bifacial panels are dual-glass, meaning they have glass on both sides of the cells - glass is much more durable and lasts longer than the typical polymer (plastic) backsheet used on most regular panels.
