However, there have been lots of practical limitations to using such systems, one of them being that you always have to follow the Sun – and that is expensive.
André Broessel, a German architect living in Barcelona, Spain, thought differently about how concentrated solar power should work and conceived a glass sphere that focuses sunlight coming from any direction even more efficiently than Fresnel lenses or mirrors of any kind.
His glass balls have a studied geometrical structure that improves the energy efficiency by 35 percent, and unlike all the other light concentrating devices, a ball lens incorporates a fully rotational weatherproof optical tracking device that can harvest sunlight on slopes and curtain walls.
The thing even works with moonlight.
Broessel sent images of his work to designboom, also check out their site to see more of his balls.