Last February, France’s minister of ecology and energy, Ségolène Royal, announced the country’s intention to, over the next five years, pave 1,000 km of roads with a composite material that can adapt to thermal expansion in road surfaces. The surfaces mark the first time roads could produce electricity while maintaining a complete ability to withstand vehicle traffic.
In late December, Colas – the company responsible for developing the technology, announced the first these roads is now open. A 1 km (0.6-mile) route in the small village of Tourouvre-au-Perche in Normandy, France, has been covered with 2,800 square miles of the panels, known as Wattway. The company has also opened an experimental site in the United States, with 50 square meters of Wattway solar panels installed at the Georgia Visitor Information Center in West Point, Ga.
“This trial site has enabled us to improve our photovoltaic panels installing process as well as their manufacturing, in order to keep on optimizing our innovation,” said Wattway Director Jean-Charles Broizat.
According to Colas, each Wattway panel contains 15-cm-wide cells making up a very thin film of polycrystalline silicon that transforms solar energy into electricity.
As Composites Manufacturing reported in February:
“These photovoltaic (meaning able to convert solar energy into electricity) cells are coated in a multilayer substrate composed of various resins and polymers. The substrate is translucent enough to allow sunlight to pass through, but also resistant enough to withstand truck traffic. The composite ‘sandwich’ is also designed to adapt to the pavement’s natural thermal expansion. The surface of the panel that is in contact with a vehicle’s tires is tailor-made to ensure equal skid resistance compared to traditional asphalt roads.”
The resin substrate also ensures that the panels can withstand heavy rains and even snow. The company notes, however, that operators need to use their machines with a bit more care on Wattway panels than on conventional pavement.
Wattway also notes that the panels can be recycled in two ways. It electrical wiring can be recycled in existing streams, and its other components, five percent of which is recycled glass, can be reused “in conventional construction material recycling streams.”
For more information on how the technology works, watch the video below: