by Oak Ridge National Laboratory Communications Staff
Step into the furniture showroom of Braden's in Knoxville, Tenn., Wal-Mart in McKinney, Texas, or an office cubicle at Minneapolis-based Aveda Corp. headquarters and the light beaming through the fixture above comes not from electrons but the sun.
Hybrid Solar lighting, a technology developed at Oak Ridge National Laboratory (ORNL) and licensed to Sunlight Direct, based in Oak Ridge, Tenn., captures the sun's rays to illuminate the interior spaces of buildings by means of a tandem lighting fixture that is both solar and electric. The system uses a 48-inch-diameter lightweight, roof-mounted collector to concentrate visible sunlight into a bundle of plastic optical fibers.
The fibers are routed to multiple "hybrid" fixtures within the building, which blend the natural light with artificial light to maintain a constant level of room lighting. One collector powers 8 to 12 hybrid light fixtures, which can illuminate about 1,000 square feet.
According to Sunlight Direct estimates, one unit can save about 6,000 kilowatt hours per year in lighting and another 2,000 kilowatt hours in reduced cooling needs for a total of 8,000 kilowatt hours per year. For parts of the country where the utility rates are 10 cents per kilowatt hour, savings can total up to $8,000 per system over 10 years.
For large floor spaces—100,000 to 200,000 square feet—this translates into energy cost savings of between $1 million and $2 million over 10 years, according to the company.
Operation and maintenance savings could account for another $300,000 in cost reductions over the same period.
There are other benefits, too. Because hybrid solar lighting brings the sunshine inside, the technology offers the bonus of improved sales, productivity and overall wellness as a result, according to studies that examine human response to natural lighting.
As a result, the system has applications in a variety of settings, from offices to schools to retail outlets.
Current customers include Sacramento Municipal Utility District customer service headquarters, San Diego State University, the University of Nevada-Las Vegas, Wal-Mart, Pacific Northwest National Laboratory, a Staples store on Long Island, N.Y., and Aveda Corp., as well as ORNL, which boasts two installations.
The system was invented by Jeff Muhs and Duncan Earl at ORNL, which patented the technology in 2003 and licensed it to Sunlight Direct in 2005.
That year the company also made available its first commercial product. Earl serves as principal of Sunlight Direct. The technology has won numerous awards, including an R&D 100 Award and an FLC award.
Duncan Earl, Oak Ridge National Laboratory researcher and founder of Sunlight Direct in Knoxville, Tenn., which is commercializing the hybrid solar lighting technology. (Click image to enlarge)
The collector for the hybrid solar lighting system, mounted atop the roof of a building, tracks and captures the sun's rays to light the rooms beneath. (Click image to enlarge)
