Just as the Egyptians would light the interior of gigantic edifices by refracting the sun’s rays down elaborate mirrored passageways, so, too, is an Oak Ridge-based technology company bringing sunlight directly to the corporate world’s most dimly lit places.

Oak Ridge National Laboratory researcher and founder of 2004 startup Sunlight Direct, Duncan Earl and his team may have borrowed the notion from ancient times, yet the hybrid solar lighting system teeters on the cusp of being adopted by the masses.

Many studies have suggested that human productivity increases when indoor workers are exposed to natural sunlight, in contrast to common florescent lighting. Big-box retailers hope that piping sunlight into its stores will provoke a rise in consumer spending. Plus, the use of natural lighting can dramatically cut energy costs—at least in regions like the southwestern United States where the word “energy” often comes coupled with “crisis.”

The hybrid system collects the sun’s rays with a mirrored disc on a building’s rooftop, filtering out the harmful rays and absorbing heat. The pure sunlight travels through plastic optical fibers that distribute the light—ranging in intensity as the sun rises and sets. On a cloudy day, the existing florescent bulbs take over.

The technology seems sound. Beta-testing sites have cropped up across the United States, including a Wal-Mart in Texas, a Staples store in New York, Braden’s Lifestyles furniture store in Knoxville and the Siskin Children’s Institute in Chattanooga.

But the company is currently operating on debt, says president and CEO, John Morris. The system is still pricey, running about $16,000 per 1,000 square feet. “We’re hoping to cut that in half in two years,” Morris says. He needs more funding for research and development—something he says has been hard to come by regionally.

“We have had a better response in California and Hawaii than we have in Tennessee,” he says, having presented at the Tennessee Valley Venture Forum last September. “The solar industry is not that big [here].

Yet the Braden’s store test site entertains plenty of interested prospects. “They have clients come in to see [the test site] about once every couple of weeks,” says store manager Nick Braden. “[The system is] expensive right now. I guess we could see a cost savings if we had it over the whole store.”

Sunlight Direct will formally launch its system later this year. Maybe that will shed some light on the venture crowds.