I never knew something wind-powered could be so beautiful, but just take a look at the Flow Light. Granted, nature itself is probably the most beautiful thing there is, so why wouldn't something powered by nature be as well? My reasoning would be because it's still man-made.
Aside from that, however, the Flow Light embodies the beauty of nature. Igendesign created it out of bamboo that rotates, producing a sort of graffiti light show. Completely sustainable, the Flow Light is specifically made for the Colombian seaside.