Bifacial Module
A PV module that generates electricity from both its front and rear surfaces, capturing light reflected off the ground or a rear-facing surface in addition to direct sunlight on the front.
Bifacial modules use a transparent rear sheet or dual glass construction so the cells can absorb light arriving from behind the panel. The contribution from the rear side, called bifacial gain, depends heavily on the surface below and behind the array. A highly reflective ground surface and ample space between module rows unlock the module's potential; a dark, cluttered mounting environment does not.
Most modern utility-scale PV uses bifacial modules by default, often paired with single-axis trackers. The combination is now the standard cost-optimized choice for open-field projects in mature markets.
Why it matters for solar installers
Accurate yield modeling is where bifacial projects are won or lost. Overstating bifacial gain inflates the customer's expectations; understating it makes your proposal lose to competitors. solarVis' 3D design engine ingests albedo assumptions and rear-side shading so installers can quote a defensible bifacial-specific yield, not a generic percentage uplift.
Common questions
- How much extra energy does a bifacial module produce?
- Bifacial gain typically ranges from 5 to 25 percent, depending on ground albedo, mounting height, tilt, and row spacing. Light-colored gravel, white membrane roofs, and tracker systems push the high end of that range.
- Do bifacial modules need special mounting?
- They perform best when the rear side is not obstructed. That means elevated mounting, open racking, and adequate rear-side clearance. Standard rooftop mounting on dark membranes captures only marginal bifacial gain.
- Are bifacial modules worth the premium?
- On utility and commercial ground-mount projects with high-albedo sites and trackers, yes. On residential rooftops with dark shingles, the bifacial gain rarely outweighs the cost premium.
