Bifacial solar

Bifacial solar modules offer many advantages over traditional solar panels. Power can be produced from both sides of a bifacial module, increasing total energy generation. They’re often more durable because both sides are UV resistant, and potential-induced degradation (PID) concerns are reduced when the bifacial module is frameless. Balance of system (BOS) costs are also reduced when more power can be generated from bifacial modules in a smaller array footprint.

Bifacial modules produce solar power from both sides of the panel. Whereas traditional opaque-backsheeted panels are monofacial, bifacial modules expose both the front and backside of the solar cells. When bifacial modules are installed on a highly reflective surface (like a white TPO roof or on the ground with light-colored stones), some bifacial module manufacturers claim up to a 30% increase in production just from the extra power generated from the rear.

Bifacial modules come in many designs. Some are framed while others are frameless. Some are dual-glass, and others use clear backsheets. Most use monocrystalline cells, but there are polycrystalline designs. The one thing that is constant is that power is produced from both sides. There are frameless, dual-glass modules that expose the backside of cells but are not bifacial. True bifacial modules have contacts/busbars on both the front and back sides of their cells.

How are bifacial modules installed?

The way a bifacial module is mounted depends on its type. A framed bifacial module might be easier to install than frameless, just because traditional mounting and racking systems are already adapted to framed models. Most bifacial module manufacturers provide their own clamps to mount their specific brand, taking away any installation hesitations.

For frameless bifacial modules, the module clamps will often feature rubber guards to protect the glass, and special care must be taken to prevent overtightening bolts and damaging the glass.

The higher a bifacial module is tilted, the more power it produces from its bifacial properties. Bifacial modules mounted flush to a rooftop block any reflected light from reaching the backside of the cells. That’s why bifacial modules perform better on flat commercial rooftops and ground-mounted arrays, because there is more room for tilt and bouncing reflected light to the rear of the modules.

The mounting system itself can affect the performance of the bifacial modules. Racking systems with support rails usually covered by a monofacial module’s backsheet will shade back rows of bifacial cells. Junction boxes on bifacial panels have become smaller or separated into multiple units positioned along the panel’s edge to prevent shading, too. Mounting and racking systems specially formatted for bifacial installations take out the question of backside shading.

Byron Eco Park's new 5MW solar farm will feature the exciting efficiency enhancements provided by bifacial solar panels.