Bifacial Panels: When Double-Sided Modules Actually Pay Off

Bifacial panels generate energy from both sides: the front catches direct sun, the rear captures light reflected from the surface beneath. Manufacturers promise +30%, but reality depends on specific installation conditions. How the bifactor (additional rear-side gain) works. It directly depends on surface albedo: fresh snow — 80–90% (hence wild winter peaks), white gravel or painted roof — 50–60%, concrete — 30–35%, dark green grass — 15–20%, asphalt — 10%. On dark ground, bifacial is practically no better than regular monocrystalline. Height above surface. A standard mounting rack gives 30–40 cm clearance — enough for +5–10%. Raising to 80–100 cm gives +12–20%. Ground-mount commercial plants on trackers with 1.5 m clearance record +25–30%. When bifacial pays off: — ground-mount on light surfaces (gravel, concrete, white membrane); — regions with prolonged snow cover; — commercial projects with trackers and elevated mounting; — roofs with white or light-grey membrane. When NOT worth it: a typical pitched roof with dark bitumen tiles, facades, grassy field. In those cases, paying 15–25% extra for bifacial pays back longer than simply a larger array of regular panels for the same money. Practical tip: count UAH per W of installed power, not UAH per panel. Often three 550W monocrystallines are cheaper and deliver more than two 600W bifacials.