New Energy Source : The Asphalt

New Energy Source: The Asphalt ? Well, not the asphalt by itself, but must have noticed that parking lots on a summer day are a killer! The thing is that asphalt gathers a lot of energy from the sun and retains it’s heat even after the sun goes down better every solar plant out there. The world is full with roads, so there will be no need to struggle to find the land to place this new invention. If we add the fact that this new technology projects itself to be inexpensive and almost invisible, it may not seem that bad at all.

Now, a research team at Worcester Polytechnic Institute led by Rajib Mallick, associate professor of civil and environmental engineering has performed studies on this patent held by Michael Hulen, president of Novotech Inc. in Acton, Massachusetts and the results seem promising.

“Asphalt has a lot of advantages as a solar collector,” Mallick says. “For one, blacktop stays hot and could continue to generate energy after the sun goes down, unlike traditional solar-electric cells. In addition, there is already a massive acreage of installed roads and parking lots that could be retrofitted for energy generation, so there is no need to find additional land for solar farms. Roads and lots are typically resurfaced every 10 to 12 years and the retrofit could be built into that cycle. Extracting heat from asphalt could cool it, reducing the urban ‘heat island’ effect. Finally, unlike roof-top solar arrays, which some find unattractive, the solar collectors in roads and parking lots would be invisible.”

Mallick and his research team, which also includes Sankha Bhowmick of UMass, Dartmouth, ran computer model tests as well as lab experiments and tests ran in real-life conditions to see how the asphalt plays the role of energy generator. The system seems to be simple: you run water trough copper pipes imbedded in asphalt slabs and the latter transfers its heat to the water. Then you may use the water for heating buildings or industrial processes or you can pass it through a thermoelectric generator to produce electricity.

The studies have shown that asphalt collects a considerable amount of heat from the sun and that it reaches the highest temperature a few centimeters below the surface. That is where the heat exchanger should be located in order to get the most out of the asphalt’s energy. Studies have also shown that the asphalt’s composition makes a difference in the heat it retains. Highly conductive aggregates, like quartzite work towards heat absorption as well and applying a non-reflecting paint can increase the energy asphalt stores.

Mallick concludes that the clue in making asphalt an energy source we will use in the future relies on replacing the copper pipes that they used in the studies with a more efficient heat exchanger system. “Our preliminary results provide a promising proof of concept for what could be a very important future source of renewable, pollution-free energy for our nation. And it has been there all along, right under our feet.”

Who knows, maybe in a few decades, the road you are jogging on provides the electricity you need to recharge your cell phone or music player…