Big brand double-sided solar panels

A new paper analyzes the cost efficiency of different double-sided solar panels. Solar researchers keep finding new ways to scrub energy out of less-than-ideal sunlight situations— even nighttime. The research found that single axis tilt is still the best combination of energy efficiency and cost.

The technology behind solar panels continues to evolve and improve. Manufacturers are now able to produce bifacial panels, which feature energy-producing solar cells on both sides of the panel. With two faces capable of absorbing sunlight, bifacial solar panels can be more efficient than traditional monofacial panels – if used appropriately.

Most of the solar panels you see are mono-facial solar panels. Sunlight hits the top face of the solar panel, and it generates electricity. But those aren't the only kind of solar panel that is out there. There's another type – bifacial solar panels. With bifacial panels, an extra part of the solar panel produces electricity – the back face.

The design allows solar energy to be captured from both sides, with the back panel achieving an efficiency of 91-93% of the front side. Developed at the US Department of Energy's National Renewable Energy Laboratory (NREL), the bifacial solar cells harvest sunlight that is reflected onto the back of the cells.

And, as we'll discuss, bifacial panels are also more expensive than traditional single-face panels, which can affect the breakeven point of your investment. Bifacial solar panels can capture light energy on both sides of the panel, whereas monofacial panels (AKA traditional solar panels) only absorb sunlight on the front.

In a new paper, a large team of researchers led by Carlos D. Rodríguez-Gallegos of the National University of Singapore ran analyses on panels that are both “bifacial,” meaning double-sided, and tracking, meaning they follow the sun's path across the sky.