Earlier quoted context omitted.
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.
Yes, I think you're right. 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.