A handful of buildings in California are beginning to try a new kind of indoor lighting: sunlight without windows. It’s called hybrid solar lighting, and it is being marketed by a company called Sunlight Direct. During the day, sunlight is captured and channeled into lighting fixtures, then at night, the fluorescent bulb takes over. On the roof, sunlight is captured using a large dish that tracks the sun. The concentrated light is channeled through the building with bundles of optical fibers.
The sunlight bounces twice. Once, off the big mirrored dish, then off of a smaller secondary mirror, which focuses everything down into the fiber optics. The mirror filters out unwanted ultraviolet and the infrared rays.
Here is a video about the system:
There is even a psychological benefit, according to Kostas Papamichael, Associate Director of the California Lighting Technology Center in Davis. “We know that people like daylight,” he says. “We know that daylight gives the best color rendering. It links us to the environment and satisfies biological needs that we have. Not necessarily at the level that you get it from a window — and, next to it, by a skylight — but some connection to the exterior for sure.”
Presently, the only place you can see hybrid solar lighting is Tennessee and in a few businesses in Davis, but a home version should be available next year.
Via: ABC Local