Wattway - described as ‘the Solar Road’ - is the fruit of five years of R&D in a partnership with the French National Institute for Solar Energy.
The panels can be used on any road around the world, said Colas, and are able to bear all types of vehicle traffic, including trucks. They are just a few millimetres thick, yet are described as being extremely sturdy, skid-resistant, designed to last. Panels are installed directly on the pavement, without any additional civil engineering work.
With 1km-long section of Wattway panels, it is possible to power the street lights for a town of 5,000 inhabitants, said Colas. The system is also seen as a first step in creating ‘intelligent roads’ that can manage traffic, gather maintenance information and even charge electric vehicles.
The photovoltaic road surfacing concept is said to be the first of its kind in the world. Wattway panels comprise photovoltaic cells embedded in a multilayer substrate. These cells collect solar energy via a very thin film of polycrystalline silicon that enables the production of electricity. On the underside of the panels, there is a connection to a lateral module containing the electrical safety components.
Wattway is able to provide power to street lights, signs, tramways, as well as housing, offices and so on, said the company. For example, 20m² of Wattway can supply enough electricity to power a single home excluding heating.
Colas chairman and CEO Hervé Le Bouc said: “Today, our Wattway process is unique on a global level. The Solar Road will play a part in the energy transition, and is a building block for Smart Cities.” A road that can produce electricity is a connected road, according to the company. The developers said that roads of the future will be intelligent and able to communicate thanks to widespread development in sensors making it possible to provide real-time information on traffic, to manage traffic dynamically, and to roll out automatic diagnosing programmes in the pavement itself. One can also imagine electric vehicles being charged via induction technology.
The system is protected by two patents and is described by as providing the road with an additional new function: producing clean, renewable energy locally.
One of the applications is in isolated, off-grid areas, when population density is so low that the cost of hooking up to the electricity network is prohibitive.