Hybrid solar lighting, which is nearly 10 times more efficient than the most affordable solar cells today, is a concept being developed at the Department of Energy's ORNL. Jeff Muhs, who leads the research effort, notes that the technology offers additional advantages compared to more traditional approaches of harnessing the sun's light and energy.
"Unlike conventional solar energy approaches that convert sunlight into electricity and pay the price of photovoltaic inefficiency, hybrid lighting uses sunlight directly," Muhs said. "Roof-mounted collectors concentrate sunlight into optical fibers that carry the light inside buildings to hybrid light fixtures that also contain electric lamps."
As the two light sources work in tandem, control systems keep rooms at a constant lighting level by dimming the electric lights when the sunlight is bright and turning them up as clouds move in or as the sun sets. The result is a dramatic improvement over conventional approaches to bring sunlight into buildings.
The hybrid solar lighting system also overcomes a number of limitations of conventional approaches.
"Daylit buildings are comparatively more costly to design, more constrained in terms of space utility, more difficult to cool during the summer, more difficult to evenly illuminate and more likely to develop maintenance problems caused by large roof penetrations," Muhs said.
From an economic perspective, a study for DOE by the Antares Group concluded that up to 1 million hybrid solar lighting systems could be in use by 2020, saving rate payers billions of dollars annually.
Scheduled to speak at the first of what is planned to become an annual event are Bill Baxter, director of TVA, Glen Strahs of DOE's Office of Solar Technologies, and several representatives from ORNL, universities and industry. The summit will focus on policy, technology and market forces that influence the development and commercialization of hybrid solar lighting.
Also scheduled to attend are representatives from several of the nation's major commercial lighting products and technologies, and major utilities. Muhs envisions the summit leading to a valuable exchange of ideas and ultimately collaborations among DOE, universities and industry.
"Virtually everyone has a stake in this," Muhs said. "From energy and environmental policy makers to scientists, engineers, architects, and solar and clean energy advocates, this is a technology that can make a difference to the environment and to people's quality of life."
In addition to demonstrations planned by TVA, the Mississippi Technology Alliance and the Sacramento Municipal Utility District, retail giant Wal-Mart has expressed interest in hybrid solar lighting and is considering testing systems at new stores in the Sun Belt and the Midwest.
To learn more about the summit being held at the National Transportation Research Center in west Knox County, visit http://www.
ORNL is a multiprogram facility managed for DOE by UT-Battelle.
NOTE TO EDITORS: You may read other press releases from Oak Ridge National Laboratory or learn more about the lab at http://www.