Researchers use road surface as energy source

Did you know the ground temperature is constant throughout the year? If we could harness the energy stored in the ground, it would be a huge new energy source. Taher Ghalandari, researcher at the Faculty of Applied Engineering at UAntwerp, wants to harvest heat from roads in summer to melt snow on roads in winter.

 

Early on in their existence, humans discovered that in winter, it's warmer underground than outside; for example, our ancestors used hot springs for bathing. Geothermal energy has always fascinated us. Since it's also renewable, vastly available, and free to use, it has become increasingly interesting to scientists as well. ‘Road surfaces absorb significant amounts of solar radiation during summer, due to the dark colour of asphalt pavement’, says Ghalandari. ‘The temperature can get as high as 70 °C, which can be detrimental to the material's service life. But it also provides an infinite renewable heat source.’ Eureka!

An infinite heat reservoir

 

Ghalandari’s experiment involved embedding pipes in the asphalt pavement. By pumping cold water from the ground through these pipes in summer, the road surface cools down and the circulating water heats up. This heat can be either directly used for domestic applications or stored for winter in two thermal storage boreholes, each a hundred metres deep.

 

‘The results of my PhD research show that geothermal pavement systems can harvest 25-35% of all incoming solar radiation’, he explains. ‘As these systems can increase the temperature of the water supply up to 30 °C, they can be integrated into home heating systems and provide hot water for your shower. The extracted heat can also help keep roads or people's drives snow-free in light snow conditions.’