01 Energy


Colas addresses the challenges of climate change, limited energy resources, and rising energy costs by investing both in the area of energy efficiency and in the avoidance of greenhouse gas emissions.

In determining its carbon footprint, the Group refers to its Scope 3a (other indirect) emissions as defined under ISO 14064 and follows the guidelines of the GHG Protocol. This calculation includes upstream usage relating to the Group's business operations but not downstream usage, since the impact of road traffic on the infrastructures built or maintained by Colas is at once considerable, difficult to quantify, and beyond the Group's control.

In 2019, the Group's consolidated worldwide carbon footprint amounted to 13 million tons of CO2 equivalent, two-thirds of which was generated by raw materials and construction materials. Due to the Group's vertical integration, the portion of this total generated directly within the Group may be estimated at 40%. It is also important to bear in mind the high degree of uncertainty in this type of calculation (greater than 30%) due to disparities between systems for measuring domestic and international data, difficulties in determining the carbon costs of certain services provided by suppliers and sub-contractors, problems in collecting or converting data, etc.

On the basis of this analysis, energy savings are being achieved (representing between 1% and 2% of the Group's total carbon footprint) thanks to actions pursued in two areas:

  • limiting the energy consumed by the Group's business activities
  • the energy content of products and techniques offered to customers

Despite this methodical commitment, it is estimated that the potential for total reductions is capped at about 20% due to the fact that Colas is not able at present to change either the specifications of the engines installed in the machines it purchases, the fuel used in these engines (in particular as a result of increasingly stringent regulations), or the carbon footprints of cement or asphalt. In relation to all of these factors, Colas is dependent upon regulatory and technical developments affecting its suppliers' offerings. 

02 Energy consumption and energy efficiency

Energy consumption and efficiency

In 2012, the Colas Group launched Cleanergie, developed for heavy-vehicle drivers and machine operators. The Cleanergie program also has a great deal of support at work sites and production sites, with a growing range of initiatives and efficiency indicators.

The economic stakes at hand represent potential savings of some ten million euros, as well as highly valuable improvements to safety at the workplace and on the road.  In the end, this program involves every challenge posed by responsible development: more savings, more safety, more environmental friendliness.   

In this frame, the Group has analyzed impact on 40 sites (works, plants, quarries) and helped raise awareness of the managers involved.  As such, an expert steering committee for each line of business has been set up.  Some one hundred best practices and opportunities were collected from the field. The findings showed that three-quarters of Colas’ direct energy consumption can be broken down evenly between asphalt plant burners and fuel consumption by machines and vehicles.   

Colas systematically measures fuel consumption at its asphalt plant burners and methodically monitors over 500 plants.  

In addition to environmentally-friendly technical alternatives, the following techniques help save energy indirectly: 

  • warm mixes enable energy savings of 15% during the manufacturing process, compared to hot mixes. In 2018, warm mixes represented 22% of Colas’ total asphalt mix production;
  • recycled materials, in particular reclaimed asphalt pavement (RAP) help save bitumen, aggregates, and transport, thus saving energy along the entire service life cycle; 
  • in place pavement recycling, which saves energy in terms of materials and transport.  

Colas also focuses on two other issues:

  • measurement tools: to assess improvements in energy efficiency, Colas must be able to measure its fossil fuel consumption, since electricity is only a small portion of the Group’s total energy footprint.  While it is fairly easy to track the consumption of asphalt plant burners, accurately monitoring the consumption of nearly 49,000 machines and vehicles across 2,000 material production units and 800 construction business units is much more complicated, despite the fact that it represents the most substantial means of potential progress.  To improve monitoring, Colas has equiped vehicles and machines with on-board consumption monitoring systems: 25% of machines and 25% of vehicles were equipped with a monitoring system in 2018; 
  • increasing employee energy awareness: Colas is conducting an information campaign to get its truck drivers and equipment operators to reduce their fuel consumption by 20% by adopting eco-driving habits and switching off engines when equipment is idling. This campaign highlights the three advantages of eco-driving; it reduces costs, increases safety and helps preserve the environment. Although these advantages are still hard to measure, more and more people are engaged in this effort. All continuing vocational training provided to drivers includes an environmentally-friendly driving component, as well as specific training sessions on this subject developed for heavy-vehicle drivers and machine operators. The cLEANergie program also has a great deal of support at work sites and production sites, with a growing range of initiatives and efficiency indicators.

For its own transport requirements, Colas uses rail and inland waterways as an alternative to road haulage. However, there is little flexibility to replace one mode of transport with another. Colas is therefore working to improve the environmental performance of each mode and achieve the best possible balance between them by proactively adopting innovative techniques. The quantity of materials transported by rail or waterway is equivalent to nearly 3,100 freight trains (with each train containing 40 freight cars), which avoids deploying some 28,000 30-ton trucks.  

03 Energy content of products and techniques

Energy content of products and techniques

In order to help our customers reduce their carbon footprint, and consequently our own, Colas brings to bear all of its expertise in the areas of innovation, research and development to create products that respect the environment:

  • warm asphalt mixes and mastic asphalts such as Neophalte® BT, the asphalt mixes 3E® and 3E® + R, Ecomat, etc.: produced at temperatures several tens of degrees lower than typical hot-mix asphalt, these products provide energy savings of between 10% and 30% while also reducing the emission of fumes by 70% to 90%. The initial goal set by Colas is to convert 50% of its worldwide production to warm-mix asphalt within 10 years. To date, the Group's operations in the United States have made the most remarkable progress in this area.
  • the Vegeroute® line: in this range of products developed at the Group's laboratories, hydrocarbon components have been replaced by plant-based raw materials, thus acting as a carbon sink and allowing for lower production or application temperatures, sometimes even reducing the total quantity of raw materials needed to make the products. This line includes the fluxing agent Vegeflux®, binders such as Vegecol® and Vegeclair®, the hot road-marking coating Ostrea®, etc.



Colas is the developer of EcologicieL®, the first carbon footprint comparison tool for road projects, and was a key participant in the development of the eco-comparison tool known as SEVE®, which is used by all industry players in France and has been officially recognized by the French government for use in connection with bids for public works contracts, so that green alternatives proposed to customers can compete on a level playing field. In 2018, contracts won by Colas proposing green alternatives represent more than 2,600 tons of avoided CO2 emissions. But the most substantial reductions in CO2 savings are today being achieved through the recycling of bitumen recovered from demolished roads or the milling of road pavement (111,000 tons of avoided CO2 emissions in 2018). In most countries other than France, the eco-comparison of green alternatives is not authorized when bidding for public works contracts. These experiences show to what extent companies may contribute to meeting the carbon footprint reduction goals of their customers. Colas takes every opportunity to share its experiences worldwide so as to promote the use of such procedures in its international markets.