Maybe the efficiency only counts the visible radiation? So that the fact that it uses ultraviolent screws up the 7-15% (that is, if you include UV light, its much lower?) That'd be my guess...
Although it is rather low on facts and high on hype.
Although it is rather low on facts and high on hype.
From the article: Most solar cells in use today are either photovoltaic, meaning they harness only visible light, or thermal.
Also: they're engineered to stand freely in three dimensions
So you have panels that catch both visible and UV light, and can do it in three dimensions.
http://www.sunwindsolar.com/a_images/solar_insolation-b.jpg
Everything to the left of the "visible light" portion.