Tecnalia, through its Construction Unit, is participating in the Pavener project, aimed at developing a system for collecting the solar energy absorbed by asphalt paved surfaces. The two-year project is being led by the Campezo Group. The Group is focusing on quality control and research project development through its Research and Quality Control Laboratory, and presently this is one of its key projects.

The system involves collecting solar energy accumulated in pavements by circulating a fluid through pipes installed below the surface. This method works similarly to a solar collector incorporated into the pavement. The system can be implemented below any paved surface exposed to solar radiation, such as roads, pavements, car parks, airport landing runways and aprons, etc. Asphalted paved surfaces can heat up 70 degrees in days of strong sunlight, and given the large paved surface area available, there is a great potential for the recovery of this energy.

The system can be designed for multiple applications, the most novel of these being its use as a solar collector, with great potential in the building sector. Incorporating concepts such as heat storage and heat pumps into the developed system, the accumulated solar energy may be used in low-temperature applications such as the air-conditioning of buildings, sports and leisure centres, swimming pools, and hot water supply. Another potential application of the system is its use for maintaining the temperature of the asphalt above freezing levels in winter, thus preventing the formation of ice on the roads. Apart from the benefits to road safety, this would reduce the amount of salt needed to be used to prevent frost.

The system would reduce consumption of fossil fuels, as well as greenhouse gas emissions to the atmosphere, as a renewable source of energy is exploited. Moreover, the maintenance required for roads is reduced, as road surface temperature can be maintained stable both in winter and in summer, thus reducing the appearance of cracks and grooves in the paved surfaces. An additional advantage of the system is the reduction of the urban heat island effect, as excess heat is extracted from the paved surfaces.

The Construction Unit at Tecnalia is researching into the thermal and mechanical properties of the system through experimental simulations and measurements, with the goal of optimising the system configuration depending on the application. Structural stability and thermal behaviour are the key aspects to consider in the development of the system.

The performance of the system will be further studied after the construction of a prototype installation.