Looking for an instant power boost for your solar panels? Slap on a large, transparent sticker by Genie Lens Technologies to get 10 percent more juice. The polymer film, which can be applied to panels you already have installed, comes riddled with microstructures that bend incoming sunlight for better absorption. More light equals more electricity, which in turn lowers the per-watt cost of solar power.

The inexpensive film works by preventing light from bouncing off the surface of the panel, according to Seth Weiss, the company’s CEO and co-founder. Not only does the sticker trap light inside the semiconductor materials that convert light into electricity, but it also diverts incoming rays so that they travel across — rather than through — the panel, bettering their chances of being absorbed.

Tests at the National Renewable Energy Laboratory showed that the film increases power output by between 4 to 12.5 percent, with the biggest improvement occurring when the sky is overcast and incoming light is diffuse. Although adding the sticker, whether in the factory or on solar panels already installed, raises the overall cost of the panels by 1 to 10 percent, the additional electricity generated makes up for the price.

A more efficient solar panel also means getting by with fewer solar panels, according to Travis Bradford, a solar industry analyst and president of the Prometheus Institute. As a result, other costs such as shipping and installation could also drop. Just one downside: Although the film has been rated for 20 years, it hasn’t been tested for durability — scratches, discoloring, and trapped dust can actually lower power output over time.