Solar roads

2013-01-31 14:21:35

Solar roads

In 2010, according to Eurostat, a little over three quarters of  the total freight that moved across the EU-27 did so by road. The importance of the network is shown even more clearly when it is affected by accidents, or by winter snow and ice. It would however be fair to point out that, apart from performing this vital role as Europe’s transport arteries,  major roads are not much use for anything. Not, perhaps, until now. An electrical engineer from Idaho believes that the roads of the future can generate electricity, and from this can be made to perform many more functions. Step forward, Scott Brusaw. According to Brusaw, tarmac and

concrete carriageways can be replaced with an appropriately strengthened heat-absorbing glass, within which are embedded photovoltaic cells: effectively, he is proposing to convert roads into gigantic linear

solar panels. The electricity would power embedded heating elements, which could melt snow and ice in winter, keeping traffic moving and reducing accidents. Fewer potholes and ruts would be likely, reducing maintenance costs. It could illuminate the carriageway at night, further contributing to safety, particularly where no street lighting exists. It could recharge electric vehicles continuously, removing concerns over their range. And Brusaw’s idea goes even further: his design can incorporate microprocessor-controlled pressure sensors and coloured LED lights, making the road surface interactive. A 4 metre square prototype panel of the material can be made to flash the words “SLOW DOWN” remotely, in response to pedestrians crossing a pressure-sensitive pad.

There are, as always, issues to resolve. The new surface is expensive. The properties of the glass need to be refined and its acceptability established (the English often use the phrase “like driving on glass” when a road

surface is frozen and dangerous).But a series of intermediate steps, such as replacing car parks or driveways could surely provide critical experience; and generate useful electricity. And so to cost. According to

Brusaw, the price of tarmac rose sixfold in the period 2007-2010. He also calculated in 2010 that replacing the 25,000 square miles [64,750 square kilometres) of tarmac within the lower 48 States* with his material

could generate three times the electricity required by the US; or almost satisfy the entire global demand. This magazine suggests that a small proportion of the current investment in renewable technologies might help bring

this innovation into production; and on to Europe’s roads. Putting aside the colossal potential it represents, one cost that cannot be quantified is that of the lives it might save.