New Scientist Breaking News - Stored summer heat de-ices winter roads

New Scientist Breaking News - Stored summer heat de-ices winter roads: "Stored summer heat de-ices winter roads


The blazing heat of the summer sun can be used to prevent roads from icing up in winter.

In a trial of the idea, a network of polyethylene water pipes 25 millimetres in diameter has been buried below a section of private road in the UK. The pipes are laid in rows about 15 centimetres apart and at a depth of 12 centimetres, where the ground temperature is normally about 12 ?C on average. In the summer this can rise to 25 ?C.

The sun warms the asphalt at the surface, which absorbs heat and in turn warms the water in the pipes. This is then pumped for storage to a second array of pipes at the side of the road, which are insulated by a 1-metre-thick layer of polystyrene.

Then in winter, when sensors detect that the temperature of the road surface has fallen to 2 ?C, the warm water is pumped back to the pipes under the road where it warms the ground and prevents ice from forming on the road surface."