Power Road®: producing thermal energy from roads
We created and are rolling out Power Road®, a technology that turns roads into sources of thermal energy. How does it work? It captures the energy from the sun’s rays on the road, stores it and releases it into nearby buildings and other facilities via a heat pump system.
Addressing the issues around the energy transition...
Power Road® technology turns roads into sources of energy. And 1.2% of metropolitan France is covered with roads, so there are 6,000 sq. km of them available in the country. Most of them are coated with blackish bitumen, and their temperature can reach 60°C on the surface and 40°C 10 cm below, principally due to the sun. This thermal energy can be captured, but it had never been tapped before. Now, roads can produce heat from this renewable source and transfer it to places that need it nearby. Power Road® can also mitigate the effects of urban heat islands: by capturing and storing heat, it avoids roads becoming overly hot.
... And local needs
Power Road® is essentially a heat exchanger built into the road. The heat exchanger is a network of pipes (which are fully recyclable) filled with a fluid that carries heat. And it is reversible, so it can:
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capture thermal energy from the sun in summer;
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release that heat, especially to melt snow and ice on roads, in winter.
Power Road® blends into nearby energy systems to meet local needs. In “summer” mode, it stores the energy in the ground to use it in winter to warm homes, swimming pools, industrial facilities and other buildings alongside it. In “winter” mode, the heat in the soil clears snow and ice from the road.
A closer look at… 4 use cases
Eco-districts typically use warm water circuits to heat indoor areas and supply hot water. Several sources of energy, including Power Road®, can be combined to supply this warm water.
A Power Road® system under a car park by a swimming pool can cover one-third of the pool’s heating needs.
Power Road® heat exchangers under 1,000 sq. metres of road in a housing development can capture enough energy to heat and supply hot water to 20 homes (each 120 sq. metres) in accordance with the requirements in France’s 2012 thermal regulation.
A Power Road® system under the apron tarmac can help to deice the runway, easing winter maintenance work (which as a rule involves some 40 vehicles and pieces of machinery).
Power Road® enhances roads with new features while they continue to serve their principal purpose.
