Understanding bifacial solar panels
Bifacial solar panels capture light on both their front and rear surfaces, allowing them to harvest direct sunlight on the front and reflected or diffuse light on the back. They are built with transparent back sheets or glass and mounted to allow light to reach the rear side.
When bifacial panels are beneficial:
- High albedo environments: Surfaces that reflect light well—such as white rooftops, light-colored gravel, sand, or snow—boost rear-side gains.
- Elevated or ground-mounted arrays: Systems with space beneath panels for reflected light to reach the back side see the biggest relative benefit.
- Carports and canopies: Elevated mounting and reflective ground surfaces make bifacial modules effective.
Advantages and trade-offs:
- Higher energy yield: Bifacial modules can increase output by a percentage that varies with site conditions—commonly 5–20% or more under favorable reflectivity and mounting height.
- Cost considerations: These panels and mounting systems may have higher upfront costs, so the economics depend on expected yield improvements.
- Installation specifics: Accurate modeling is needed to capture back-side gains; ground albedo, mounting height, and tilts matter.
Practical tips
- Use bifacial modules when the site has reflective surfaces or when panels can be elevated off the roof.
- Pair with accurate site modeling to ensure expected gains justify the extra cost.
Bifacial panels can deliver meaningful performance boosts in the right setting but are not always the best choice for tightly packed rooftop installations with little room for back-side exposure.