Solar Energy Used to Keep Roads Heated During Winter

A new way of heating roads during the winter to prevent the roads from freezing is being tested in the UK. It uses solar power energy. If successful and cost-efficient, this technology will eliminate the need of salt trucks, which are extremely expensive to send out and maintain for obvious reasons. Also, the gas-powered trucks add pollutants to the air and the salt is not environmentally friendly either.

Essentially, the technology is very simple, yet is currently extremely expensive. A series of tubes will be placed linearly underneath the surface of the road. These pipes will be made out of a combination of plastics and will be filled with water. This mechanism is called interseasonal heat transfer, or IHT. In summer, when road temperatures can reach 40C, the water is warmed and pumped to pipes insulated with polystyrene. In winter, when sensors detect the temperature at 2C, warm water is pumped back under the road to heat the ground and prevent ice forming.

At this point, the technology is still very expensive. As a result, only “cold spot” on highways are being considered for this mechanism. These are spots that are known to become frozen earlier than other parts. So, realistically salt trucks will not be fully replaced at this point in time. At least, that is not the goal.

This plan follows a 2-year trial on a small stretch of highway in the UK. Scientists found enough heat was captured in the summer of 2006 to keep the road above freezing for almost all of the following winter. On average, the heated surface was 3C warmer than the surrounding ground. This particular test also showed that buildings near the road could be heated by the solar heat captured by the roads. In another instance, an elementary school had discovered that its playground could be heated by roads. Apparently solar energy can produce half the amount of energy captured by solar panels placed on the roof of a building, but at one-twelfth the cost.