There are around 2.6 million miles of paved roads in the United States, and more than 11 million miles worldwide. What if they could be put to use generating electricity, through solar panels?
Solar panels, with delicate electronics sandwiched in glass, aren't exactly well-suited to withstand traffic from cars or 40-ton semis. But an electrical engineer, inspired to do something about climate change, has spent the last several years working with his wife to figure out how to make solar roads a reality. Scott and Julie Brusaw created the first prototype for Solar Roadways in 2010, funded by a grant from the Federal Highway Administration, and this year they're testing a fully-functional solar parking lot.
This is how it works: the panels are topped with a super-strong, translucent layer that provides traction, but lets sunlight through. The middle of the panel has solar electronics to gather energy, and can also light the road with LEDs at night, similar to the Smart Highway being tested this year in the Netherlands. The electronics can also monitor activity—even tracking the panel if it's stolen. The middle has a heating element to warm the roads to remove ice and snow automatically. At the bottom, the panels have a layer to distribute power to homes and businesses connected to the Solar Roadway.
If the panels replaced all paved surfaces in the United States, from roads to sidewalks to playgrounds, the developers have estimated that they could produce more than three times the amount of electricity currently used in the whole country—and almost enough to supply the entire world.
Why not just install solar next to roads, or on canopies above them? The Brusaws argue that it would be too expensive; they plan to use money already budgeted for roads to build the solar highways, and also see the roads as a replacement for an aging power grid. The extra benefits, like safer driving through well-lit, ice-free roads, can help save lives. The roads can even help save wildlife: when a panel detects that a deer or another animal is crossing the world, it can flash an LED warning in an earlier part of the road to alert oncoming drivers.
It's pretty amazing technology, though still very much in development. It's unclear how soon our roads can get this smart.
Images courtesy of Solar Roadways