Geothermal heat keeps road clear of snow

Geothermal heat keeps road clear of snow

For car drivers it is a nightmare: Sudden black ice or heavy snowfall can render a street impassable within minutes. French company Eurovia has developed a technique that utilises geothermal energy to keep roads clear of snow and ice.
By eeNews Europe


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In its research centre in Mérignac near Bordeaux, Eurovia has developed an innovative road. The goal of their project, Novatherm, was utilising the geothermal heat to clear the road of ice and snow in winter time. In the region Franche-Comté, the Eurovia engineers tested two different approaches: Horizontal and vertical heat exchangers. Both designs proved to work well. The vertical type turned out to be more effective; however it requires expensive and complex deep drillings up to 40 metres (about 120 feet) The horizontal variant also achieved satisfactory results: De-icing took place at a speed of 1 cm per hour.

Both variants required deployment of a heat pump with 30 watts and a COP (Coefficient of Performance) of 4. This translates in 4 watts of thermal energy generated for every watt of electrical energy consumed. In comparison with direct electric road surface heating, the Eurovia approach thus consumes only 25 percent of the energy and the de-icing effect is much faster.

What’s more, the process is reversible. In summer time, the system can be used to remove heat from the road and makes it available to adjacent buildings. This approach of road surface temperature regulation increases the road’s durability since outside of the temperature range between 0 and 38 degrees Celsius the road is more susceptible to wear and damage.

Eurovia’s achievement has been awarded the sustainability award of construction company Vinci, Eurovia’s parent company. The technology is intended to be deployed in Smart Grid projects where they can be controlled via load management software.