A solar roadway is a proposed road made from a series of glass panels intended to replace asphalt streets while reducing energy costs and assisting drivers. According to plans and prototypes still being developed in 2011, each solar road panel would absorb the sun's energy, with the energy generated from a nationwide grid of these panels expected to be three times that needed to power the United States. Inside the panels would be light-emitting diodes (LEDs) intended to create the yellow and white lines commonly present on asphalt streets and to spell out messages such as “School Zone” or “Slow Down”. The LEDs also are intended to be sensitive to the presence of animals and light up to show drivers where animals are in the road. A heating mechanism in the panel would keep streets from icing over during the winter.
The predominant trait and main reason for a solar roadway is to produce more clean energy; a secondary benefit would be to create a road that is able to pay for itself during operation. To do this, each panel would be equipped with a large solar panel that would capture the sun’s energy on a continual basis. It is projected that this would provide the United States with about three times the amount of energy required annually. Along with the solar panels, many other features would be added to help drivers.
LEDs in the glass panel are intended to shine in both white and yellow to create the lines and messages commonly seen on traditional asphalt streets. This would allow messages to be changed on-the-fly and eliminate the need for painting and repainting the street. The solar roadway also would generate light, making it easier for drivers to see the road at night.
The LEDs in the solar roadway panels are intended to be able to create common street messages and lines, but they also are expected to protect wildlife. Plans for the panels call for them to be sensitive to an animal’s touch. When a deer, possum or other animal touches the glass, the LEDs would turn on, alerting drivers to the animal’s presence.
Heating mechanisms in the panels also would help during winter. Ice and snow can freeze on streets, making it dangerous to drive. The heating mechanism would ensure that snow and ice melts without the need for removal. This would ensure that the roads are safe during the winter and keep states and individuals from having to pay to remove the snow and ice.
As of July 2011, Solar Roadways Inc. of Idaho had been awarded a grant from the U.S. Department of Transportation's Federal Highway Administration to continue its development of the panel. An initial grant allowed for the development of a prototype panel. Plans for the second phase included the creation of a parking lot built using the solar panels.