These days, we can find solar panels, also known as photovoltaic cells, just about everywhere. They're on the roofs of our homes, bringing down the cost of electricity. They're even on top of a few cars. In 2019, Toyota began testing outfitting the Prius Prime with solar battery panels on its roof, hood and rear hatch door. Altogether, those panels are slated to provide up to 27.6 miles (44.4 kilometers) of electric power daily, says Green Car Reports. Two other European companies have plans to unveil solar-assisted cars, too.
Some experts have theorized that if we were to lay down a gigantic number of solar panels over a wide area, we could absorb enough sunlight to power entire cities, effectively ending our energy crisis. The problem is, there's nowhere to put them. We can't exactly stick panels across the entire countryside.
Or can we? The U.S., for example, has a network of roads all over the country. Why not place panels along the roadways as sound barriers, or an even more extreme idea – make the roads themselves out of solar panels? They have.
These "solar highways" or "solar roadways" consist of individual solar 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, according to 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.