Solar Panel System GuideMonocrystalline names a cell material while bifacial names a two-sided design, so the two overlap rather than compete directly. This page sources its facts from EnergySage and the U.S. Department of Energy and picks no favorite.
How to read this comparison
The two terms below describe different things. Monocrystalline is a cell material, cut from a single silicon crystal. Bifacial is a module design that collects light on both faces. A single panel can be both. The facts come from EnergySage and the U.S. Department of Energy. Numbers change as products update, so confirm against a current datasheet for any specific model.
Monocrystalline panels (from EnergySage)
EnergySage reports that today's residential monocrystalline panels typically fall between 20 and 23 percent efficiency, with most putting out 400 to 450 watts. It explains that because a monocrystalline cell is composed of a single crystal, the electrons that generate a flow of electricity have more room to move.
EnergySage notes the trade-off. Monocrystalline solar panels are more expensive than polycrystalline solar panels, because the production must be controlled very carefully.
Bifacial panels (from EnergySage)
EnergySage reports that bifacial panels capture sunlight from both the front and back surfaces, which lets them generate more electricity than a comparably sized traditional panel.
The extra gain depends on the setting. EnergySage notes that bifacial panels are now standard in utility scale projects, while on residential rooftop installations the rear side gains are usually modest.
Where they differ on paper
The key point is that these labels are not mutually exclusive. Monocrystalline describes the cell, and the Department of Energy notes that crystalline silicon cells are made of silicon atoms connected to one another to form a crystal lattice. Bifacial describes the module, capturing light on both faces.
A bifacial panel is usually built on monocrystalline cells, so a homeowner often chooses efficiency tier and two-sided design separately rather than picking one label over the other. EnergySage reports the rear side benefit is largest in utility scale settings and modest on a typical rooftop. These are the documented figures, not a verdict.