Roads soak up a lot of heat energy from the sun. During the summer it can often be unbearable to walk along the road in sunny areas as the heat radiating upwards can lend a stifling quality to the atmosphere.
Scientists at the Worcester Polytechnic Institute in Massachusetts have decided to develop a system that can put this heat energy to good use. By using special piping technology they can turn effectively turn the streets into giant solar energy collectors.
The idea is quite similar really. Water is pumped through pipes that are buried a few centimetres below the surface of the road. The heat absorbed by the asphalt then warms the water, which can then be used further up along the pipe to generate electricity. The transfer of the heat energy from the road to the water also helps to cool the road surface and prolong the lifespan of the asphalt. (Related article: Study Finds Libya has More Solar Resources than Oil)
Rajib Mallick, the associate professor leading the team of researchers, said that their “preliminary results provide a promising proof of concept for what could be a very important future source of renewable energy.”
Unfortunately some problems stand in the way of the success of the idea. The returns possible from the technology are unknown meaning that investors are hard to attract, and a large up-front investment is vital as installing and maintaining the pipes in the roads would be very costly.
Tim Anderson, a solar energy expert, remarked that the temperature of the water would unlikely be high enough to make any good return on investment in most cases.