Scientists are currently developing a new energy conserving technology that relies only on available sunlight. The rooftop based system would collect sunlight and distribute it through the building via special optical fibers.

The researchers, from Oak Ridge National Laboratory in Oak Ridge, Tennessee, hope that with additional light level sensors and high-efficiency fluorescent lighting for days with less natural light, the system will maintain a set illumination level.

The HSL (hybrid solar lighting) system's first trials will be the headquarters of the Sacramento Municipal Utility District in Sacramento, California and a Wal-Mart store in Kauai, Hawaii.