Colas, the transport subsidiary of Bouygues, has succeeded in producing energy thanks to photovoltaic cells installed on roads. Referred to as Wattway, this new technique of producing solar energy, is the fruit of five years of research conducted with the National Institute of Solar Energy (INES).

The usually fragile photovoltaic cells are covered with a patented transparent coating which allows them to bear the weight of the heaviest trucks. They become in this way photovoltaic slabs which are neither abrasive nor slippery. The "solar" road thus obtained is linked to a system which recovers the energy produced through an underground connection.

The slabs have been successfully tested, in the towns of Chambery and Grenoble based on a cycle equivalent to 20 years of normal traffic on a road. "If a quarter of the roads were covered, we could ensure the energy independence of France. This shows the goal behind this project", reveals Hervé Le Bouc, CEO of Colas.

"There is no need to redo infrastructure. It is a road coating commercialised in the form of slabs which are applied to roads or parking areas", reassures the CEO. The company foresees commercialising its first slabs starting in January 2016. "We will be at the same price as a solar farm, in such a way as to be an alternative to this mode of producing photovoltaic electricity", he announced.