The concept

As the energy transition becomes reality, imagine a road able to harvest solar energy and produce energy locally.

The world’s 1st ever photovoltaic road surface
Wattway is a patented French innovation that is the fruit of 5 years of research undertaken by Colas, world leader in transport infrastructure, and the INES (French National Institute for Solar Energy). By combining road construction and photovoltaic techniques, Wattway pavement provides clean, renewable energy in the form of electricity, while allowing for all types of traffic.

A new vision for roads
Wattway produces electrical energy without overtaking farmland or natural landscapes, and contributes to increasing the share of photovoltaic electricity in the energy mix, both in France and worldwide.

By the year 2050, global energy needs will have doubled.
Roads are only occupied by vehicles 10% of the time.
20 m² of Wattway panels can supply the electricity requirements of a single home.

The advantages

performance énergétique


Pavement is only occupied by vehicles some 10% of the time. Imagine the solar resources of this surface area, facing the sky.
20 m² of Wattway panels provides enough electricity to power a single home. (Source ADEME/CEREN 2014 – average French household for 1,000 sun hours/year – not including heating).

adhérence et résistance


How to reconcile the fragility of photovoltaic cells and the robust structure of a road? Wattway is composed of cells inserted in superposed layers that ensure resistance and tire grip. The composite material is just a few millimeters thick, making it possible to adapt to thermal dilation in the pavement, as well as vehicle loads, a guarantee of durability and safety.

Pose sur chaussée existante


If Wattway is so revolutionary, it’s also because of the way it is installed! No need to rip out the existing structure, Wattway can be applied directly on the current pavement, without any need for civil engineering work.

Its applications

A one-kilometer stretch of road paved with Wattway can provide the electricity
to power public lighting in a city of 5,000 inhabitants.
[Source ADEME]

Towns and cities

In urban areas, the need for electricity is growing. How to produce and how to transport the energy we need? These are some of the most important environmental issues of our times. With Wattway, electricity can be produced and used locally. Wattway fits perfectly into the smartgrids* model that will be used to design the cities of tomorrow.

In cities, Wattway’s applications are endless: public lighting, urban furniture, buildings, homes, signs, etc.

Isolated, off-grid areas

In some remote areas, it is sometimes difficult and costly to supply the infrastructures and villages with electricity. Without having to undertake any major construction work, Wattway provides developing countries with a new, durable solution for short circuit renewable energy.

The Colas Group

The Colas Group is a world leader in the construction and maintenance of transport infrastructure.
Striving to meet the challenges posed by mobility, urban development and environmental issues, Colas has built a reputation since it was founded in 1929 as an innovative, responsible Group.

After years of research in a partnership with the INES, Colas is now able to combine its expertise in roads with that of photovoltaic technology, paving the way to Wattway, the world’s first photovoltaic road surface.

Innovating for almost a century!
  • 1920

    How to make bitumen liquid at ambient temperatures for easier handling and application and ensure immediate hardening, this is the paradox solved in 1920 by Hugh Alan Mackay and George Samuel Hay, the British inventors of bitumen emulsion.
    This innovation is what gave Colas its name (Cold Asphalt), founded in 1929 to use the patent.
    Colas emulsion is used worldwide: even as early as 1930 in the United States.
    Colas is the world’s leading manufacturer of bitumen emulsion.

  • 1925

    Colas has been a longstanding partner of major automobile tracks, which provide an open air laboratory to test heavy duty pavement performance. The Group has designed tracks for prestigious circuits in France (Montlhéry, Monte-Carlo, Le Mans, Le Castelet, Nevers-Magny-Cours), the United States, Canada, Australia and Thailand.
    Backed by its expertise in road techniques, Colas has also made a name for itself in record-breaking railway infrastructure projects: in France, Colas Rail built a section of the LGV Est high speed train on which the Sncf broke a world speed record at almost 600 km/h, without damaging the tracks.

  • 1950

    As Europe was rebuilding in the wake of WWII, Colas, which had built its reputation on cold techniques, became intrigued with modern asphalt mix production and application techniques that were being used in the United States.
    Colas decides to revolutionize its production tool by embracing the new techniques and industrial equipment. The Group becomes the first company in France to be equipped with modern asphalt plants and pavers.
    At the end of the century, Colas is a well balanced group with diversified construction business and a unique material production segment.
    Colas is a world leader in the production of asphalt mix.

  • 1970

    In the 1960s, France falls behind on building highway infrastructure due to public spending issues. Colas points the way to a new idea: using a concession contract to build and operate road infrastructure. The Government likes what it hears and the country’s highway program takes off, with investment and income plans for decades to come. In 1970, Colas takes a stake in the Cofiroute network, with the first section between Paris and Orleans. Colas calls on its entire range of skills and expertise to ensure long-lasting quality and lower costs. Colas had just invented optimized overall costs in road infrastructure, the very heart of today’s Public Private Partnerships and sustainable development for transport infrastructure.
    Today, Colas is involved in a number of complex contracts (concessions, PPP, MAC, PFI, etc.) in France and around the world.

  • 1975

    Using its road business in Quebec as a springboard, Colas branches out to work on extreme voltage power lines in James Bay, in the particularly harsh conditions of the Middle North (-40°C in the winter, hostile swampland in the summer).
    This is entirely new for Colas, even for electrical engineering companies. Colas created Transelec, and made bold choices in terms of technology and logistics.
    Colas won practically half of the contracts for the power lines that were to span the immense James Bay area, which probably remains the largest jobsite in the world (surface area equal to half of France, and over a 40 year period).

  • 1977

    In the 1970s, Shell and Colas decide to design a modified bitumen to help stand up to the increasing degree of vehicle stress and strain.
    They chose to add an elastomer (SBS) to reinforce the bitumen and provide additional elastic recovery to better withstand deformation: Colflex came to be in 1977.
    The SBS modified bitumen is also used in bituminous membranes for roofing and waterproofing.

  • 1980

    At the Jakarta Airport in Indonesia, Colas used the ancestral Indonesian technique called Chicken Feet that is used to stabilize swampy soil by driving bamboo tubes into the mud.
    Colas replaced the bamboo with enormous concrete pipes, to build a runway that floats on several meters of liquid mud, but is still able to bear the pressure exerted by the landing gear of a 747.
    Over 30 years later, the runway is still in service, and has been able to stand up to South East Asia’s soaring air traffic.
    Since, Colas has continued to perform on exceptional airport projects (Chicago, USA, Roissy, France, Iqaluit, Canada)

  • 1990

    In the 1980s, the United States launched a program to replace underground tanks, and, in the event of leakage, a system to manage soil polluted by hydrocarbons.
    Colas decided to use thermal desorption, which uses plant that is similar to asphalt mixing technology. With a number of innovative choices, Colas is able to control fire and explosion risks that are inherent to the technique, and also ensure traceability and soil remediation. The Clean Earth plant, which was the largest of its type in the world for several years, never had an accident. It inspired Colas Environnement’s organization and control culture, a pioneer in ISO 9001 certification.
    Today, Colas Environnement is a leader in thermal desorption of polluted soil, and the oldest French pollution remediation company.

  • 2005

    In 2005, Colas filed a patent for a non-bituminous, pure white asphalt mix, that used a pine resin and rapeseed oil plant-based binder. This revolutionary binder is called Vegecol.
    The product is a success, and Colas becomes known as the pioneer of plant-based binders. Life cycle analysis was an integral part of the product design phase, a new eco-design program rolled out by Colas. Very quickly, Vegecol is used on high-profile projects, such as sites for the Olympic Games in London. Since this time, the plant-based offer at Colas has expanded with the Vegeroute line, including Vegeflux plant-based flux and Ostrea road marking paint. Colas continues to develop substitutes using renewable resources, as part of its Green Chemistry program.

  • 2015

    In 2014, after 5 years of research, Colas and INES (French National Solar Energy Institute) filed a joint patent for a Solar Road technology based on crystalline silicon. Very thin yet very sturdy, skid-resistant and designed to last, Wattway panels can bear all types of traffic, including trucks. They are applied directly to the existing pavement. The first pilot test sites rolled out in 2015 confirmed that the concept was a valid one. Above and beyond the technological innovation, the rapid transition from a revolutionary concept to a commercialized prototype is a genuine industrial performance. In October 2015, Colas officially launched Wattway, taking a pole position in the energy transition and paving the way to the road of the future. With this breakthrough technology, Colas gives roads a new function, that of producing energy, in addition to its traditional role of supporting mobility.


Wattway media library

Septemes-les-Vallons (France)
Septemes-les-Vallons (France)
Epron (France)
Epron (France)
Epron (France) – 2
Epron (France) – 2
Moult (France)
Moult (France)
Le Port – Reunion Island (France)
Le Port – Reunion Island (France)
Le Port – Reunion Island (France)
Le Port – Reunion Island (France)
West Point, Georgia (USA)
West Point, Georgia (USA)
West Point, Georgia (USA) – 2
West Point, Georgia (USA) – 2
WestPoint, Georgia (USA) – 3
WestPoint, Georgia (USA) – 3
Saint-Jean-d’Alcapies (France)
Saint-Jean-d’Alcapies (France)
Saint-Jean-d’Alcapies (France) – 2
Saint-Jean-d’Alcapies (France) – 2
Tourouvre – RD5 (France)
Tourouvre – RD5 (France)
Tourouvre – RD5 (France) – 3
Tourouvre – RD5 (France) – 3
Tourouvre – RD5 (France) – 2
Tourouvre – RD5 (France) – 2
Press Kit
Press Kit
Press releases
Press releases
SNA factory (France)
SNA factory (France)
SNA factory (France) – 2
SNA factory (France) – 2
SNA factory (France) – 3
SNA factory (France) – 3

Colas, official partner of COP 21

Colas wins a Climate Solutions Award for the Wattway Solar Road

As part of the COP21 United Nations Conference on Climate Change, Colas has won a Climate Solutions Award for the Wattway Solar Road. The selection jury, whose members include experts in resources and climate matters, has honored Colas with a Favorite Award in the Mitigation – Large Enterprise category.

Organized by Ademe, C3D, le Crédit Coopératif, Orée, Solutions COP21, The Shift Project and World Efficiency, the Climate Solution Awards are given out to highlight the best solutions for alleviating and/or adapting to climate change.

What's up with Wattway

Intersolar – Munich
31st May – 2nd June 2017

Viva Technology – Paris
15th – 17th June 2017

ITS European Congress – Strasbourg
19th – 22nd June 2017

Expo Future Energy – Astana
10th June – 10th September 2017

How can Wattway help you?

Be the first to pave a solar road

Local officials, you can transform your public space
to build the towns of tomorrow.
Private companies, you can produce clean energy
on your traffic lanes and parking lots.

Together, let’s build the future…

Help innovate in the energy sector and in urban development.
Get on board to the future!

Contact us now.
Together, we can imagine how Wattway can work for you!

Europe: + 33 1 77 45 20 53
USA: + 1 (855) 821-0030

Contact me

Legal information

Legal Information

The website is the property of Colas, a French Société Anonyme with share capital of 48,981,748.50 euros, registered in the Paris Trade and Companies Register under the reference 552 025 314. The registered office of Colas SA is located at 7 Place René Clair, 92653 Boulogne-Billancourt Cedex, France.

Communications Manager: Sophie Sadeler
Editorial Manager: Delphine Lombard
Design et production: Nomen
Illustration : © COLAS – José Lozano
Photo : © COLAS – Joachim Bertrand / P. Avavian / Arizona
Video : © COLAS – Nomen – Arizona

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