Scott and Julie Brusaw have been working on their Solar Roadway—literally a road made of solar panels—for several years. And, now, they’re finally ready with their first full trial: a 12 by 36 foot parking lot in north Idaho, about an hour from the Canadian border. Funded with a $750,000 grant from the Federal Highway Administration, the 5,700-watt installation is set to be completed in April, and will be a key step in proving viability.
"We’ll have something to invite company owners to come and see," Scott Brusaw says. "They’ll be able to see all the features, and how the power runs straight into our electronics lab and powers the building."
The road is made of three parts: a hard-wearing translucent top-layer with the solar cells, LED lights (for road markings) and a heating element (to keep off snow and ice); an electronics layer to control lighting and communications; and a base plate layer that distributes power to nearby homes and businesses (and perhaps electric vehicle charging stations). Plus, there’s a channel at the edge to collect and filter run-off water (including anti-freeze and other chemicals that normally leeches into the ground). The trial will test three types of PV: mono- and poly-crystalline, and thin-film.
Brusaw says a solar panel on the ground is likely to generate less power than one on a roof, because the ground can’t be pointed at an optimum angle to the sun. But the point is there is a lot more ground around than roof-space, and putting panels down, rather than up, is easier. He hasn’t calculated how expensive a solar road might be compared to asphalt—though he guesses it might be three times as much.
The big draw of the solar road, potentially, is that the panels end up paying for themselves, and that the energy can be used for all sorts of useful things, like powering lights, and rest-stop amenities. There’s a possibility to feed EV charging points, and even to charge cars as they travel down the road. (Brusaw has talked with a company developing a wireless charging infrastructure). "Theoretically, you could never run out of juice," he says.
First, though, the Brusaws have to prove the parking lot works, and start manufacturing their first commercial panels (possibly in 2014). If they get that far, it’s likely we’ll see the first solar roads, and parking lots, in cold and remote places. A highway that clears itself of ice and snow would be a big draw in the winter time.