Bifacial Panel

Bifacial solar panels generate electricity from both the front and rear sides of the module. The front captures direct and diffuse sunlight as normal, while the rear absorbs light reflected off the ground, mounting surface, or surrounding structures — a phenomenon called albedo gain.

This dual-sided energy capture can boost total energy production by 5% to 30% depending on the installation. The gain depends heavily on the mounting height (higher is better for rear exposure), ground surface reflectivity (white roofs, gravel, and snow reflect more than dark soil or asphalt), and tilt angle.

Bifacial panels typically use a transparent back sheet or dual-glass construction instead of the opaque white backsheet found on standard monofacial panels. The cells themselves are designed to be active on both surfaces — most TOPCon and HJT cells are inherently bifacial.

For ground-mount installations on light-colored surfaces, bifacial panels are an easy win. Commercial rooftops with white TPO or PVC membranes also provide good reflected light for bifacial gain. On residential rooftops mounted close to dark shingles, the bifacial advantage is minimal.

When evaluating bifacial panels, look at the bifaciality factor — the ratio of rear-side efficiency to front-side efficiency. High-quality bifacial panels achieve 70% to 85% bifaciality, meaning the rear produces 70-85% as much power per unit of incident light as the front.