Start with the surface below and behind the module
Rear-side irradiance depends on what light can actually reach the back of the module. Light-colored ground or roofing can reflect more than dark or shaded surfaces, but the exact result depends on the complete geometry.
Check mounting geometry
- Module height above the reflecting surface.
- Row spacing and tilt.
- Rear obstruction from rails, clamps, cables and equipment.
- Self-shading and neighboring rows.
- Seasonal dirt, snow or vegetation conditions where relevant.
Separate front-side nameplate from modeled bifacial gain
Use the front-side rated power for the equipment identity. Treat rear-side contribution as an energy-model input with stated assumptions. Do not turn a manufacturer “up to” bifaciality figure into guaranteed annual generation.
Keep electrical and mechanical checks in the design
Higher irradiance can change operating current. Confirm inverter/optimizer current limits, string design, structural loading, module dimensions and local certification. The Canadian Solar TOPBiHiKu6 CS6.2-66TB-620H page is one current Melnti example of a bifacial module.