Hybrid Solar Lighting Goes Into Beta Testing
It turns out that the Australians aren't the only ones experimenting with technologies that literally bring sunlight into a building. The folks at Tennessee's Oak Ridge National Laboratory have developed a solar hybrid lighting system that they'll be beta testing over the next few months at twenty-five locations around the US, including the Sacramento Municipal Utility District customer service headquarters, San Diego State University, University of Nevada, Las Vegas, and a Wal-Mart in McKinney, Texas. Preliminary tests from five locations look promising, and demonstrate this technology holds great potential to save energy and money.
The hybrid solar lighting technology uses a rooftop-mounted 48-inch diameter collector and secondary mirror that track the sun throughout the day. The collector system focuses the sunlight into 127 optical fibers connected to hybrid light fixtures equipped with diffusion rods visually similar to fluorescent light bulbs. These rods spread light in all directions. One collector powers eight to 12 hybrid light fixtures, which can illuminate about 1,000 square feet. During times of little or no sunlight, a sensor controls the intensity of the artificial lamps to maintain a constant level of illumination. ...Though still in testing, Oak Ridge and Sunlight Direct have high hopes for hybrid solar lighting: their market projections show that, if the technology succeeds during the beta phase, 5,000 of these systems could be installed nationwide in five years. Costs are still an issue at this point, but the project participants believe that planned design changes will make this lighting option very attractive in parts of the country where solar potential is ample and current electric costs are high. ::Oak Ridge National Laboratory via TerraDaily and the What's Next Network (via Hugg)
The system can save about 6,000 kilowatt hours per year in lighting and another 2,000 in reduced cooling needs for a total of 8,000 kilowatt hours annually, according to [technology licensee and Oak Ridge start-up] Sunlight Direct estimates. Over 10 years, for parts of the country where the utility rates are 10 cents per kilowatt hour, that can result in savings up to $8,000 per hybrid solar lighting unit. 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 Sunlight Direct. Operation and maintenance savings could account for another $300,000 in savings over the same period.