Homeowners love natural lighting. Keep your house bright and cheery, without expensive electricity or candles. Like windows, but those can compromise privacy, or skylights, which only work on the topmost floor (for fairly obvious reasons).
A Sweedish design firm, Paras, has a means of transporting it in fiber-optic cables down to any room, even the lower floors and/or basement. The light is unchanged in any way, including color temperature, from the time that it's collected until it shines upon your room, satisfying fans of the sun's color temperature and so on.
The cables alone aren't the interesting part. The interesting part is the collection devices on the roof. They use a parabolic array, like a tiny satellite dish, to collect the maximum amount of light and focus it into the cable, allowing one dish the light two rooms.
Ah, the power of the sun.