Thanks to a steep drop in the price of photovoltaic cells, you're more likely to see solar panels on buildings as you drive along.

But what if one day you drove on those solar panels as well?

Embedding solar panels in roadways has been proposed before, but the French government may be about to take the most ambitious step toward that goal yet.

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The country's environment agency plans to resurface 1,000 kilometers (621 miles) of roads with solar panels, according to Australian car site Motoring.

Those roads will use a purpose-built solar panel called Wattway, developed by road-building company Colas in partnership with the French National Solar Energy Institute.

Colas claims the Wattway panels can be directly applied to an existing road surface, and will provide comparable levels of grip to conventional paving materials.

Colas Wattway road-mounted solar panels

Colas Wattway road-mounted solar panels

And while the panels are just 7 millimeters thick, Colas claims they can stand up to the wear and tear of heavy vehicles being driven over them continuously.

If the Wattway-paved roads really do pass that durability test, Colas claims they will provide ample power.

Four meters (13 feet) of road can provide enough electricity to power the average French house (excluding heating), the company says.

ALSO SEE: Solar Panels On Dutch Bike Lane Produce More Power Than Planned (May 2015)

But only real-world use can verify those claims.

One disadvantage of solar panels laid flat on a roadway is that they can't harvest as much energy as angled, roof-mounted panels.

Wattway is undergoing final trials. If all goes well, the full 621 miles of panels will be laid over the next few months.

Colas Wattway road-mounted solar panels

Colas Wattway road-mounted solar panels

Colas and the French government aren't alone in pursuing the dream of solar roads.

A Dutch company called SolaRoad began laying solar panels on a bike path near Amsterdam last year, to test technology it hopes will eventually be applied to roadways.

And in the U.S., there's Solar Roadways, which became widely known through a successful crowd-funding campaign, and is now refining its own designs.

MORE: Solar Roadways Smashes Crowdfunding Target, Still Raising More (May 2014)

In November 2015, Solar Roadways was awarded a two-year, $750,000 Small Business Innovative Research contract by the U.S. Department of Transportation to conduct additional tests on its panels.

All of these companies have one thing in common: a goal to use roads as a source of renewable power for everything from nearby streetlights, to buildings.

Whether any of these projects survives to achieve that goal remains to be seen.


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