Each Solar Roadway panel consists of three basic layers: the base plate layer, electronics layer and the high-strength, translucent road surface layer.

Courtesy of Dan Walden

Advantages of Solar Panel Highways

You've probably seen traffic warning signs on the side of the road with small solar panels attached to them. While they're one example of how solar power can aid our driving experience, they're only the tip of the iceberg. In August 2008, the Oregon Department of Transportation installed a row of solar panels five feet (1.5 meters) wide and two football fields long at an interchange near two interstate highways. The panels are designed to feed into Portland General Electric's grid, supplying nearly 30 percent of the power necessary to run the highway's lights at night [source: Rivera].

As you can see, solar panels already have applications on our roads. But some are taking that idea even further and proposing that we build the roads themselves out of solar panels. Solar Roadways, a U.S. company, has a plan to create structurally engineered rows of solar panels that cars and trucks can actually drive on. And while we're driving on them, they'll collect solar power that can supply power to our homes and businesses.

The "solar highways" consist of individual panels with three layers -- a top layer of high-strength, textured glass that provides traction for vehicles, an array of solar cells beneath that for gathering energy, and a base plate that distributes the collected power [source: Solar Roadways].

They're more than just solar energy collectors, too. The panels contain LED lights, powered by the sun, that can act as road and warning signs built into the road itself. In addition, they can use gathered heat to melt snow and ice on the roads.

The company also says that having a source of electricity beneath cars at all times would make it easy for electric vehicles to stay charged up at roadside stations -- clearing the major hurdle that EVs face, which is finding places to charge when they spend their batteries [source: Solar Roadways].

With each 12-foot by 12-foot (3.7-meter by 3.7-meter) panel capable of producing 7.6-kilowatt hours of power each day, each mile of solar roadways could produce power to run as many as 500 homes [source: Jacquot].

The U.S. Department of Transportation thinks it's a good enough idea to give the company a $100,000 grant. But can the solar panels really hold up? On the next page, we'll look at the disadvantages of solar panel highways and see if the idea is truly feasible.