Just Follow the Solar Brick Road

August 25, 2008

Last week, in case you missed it, Zurich hosted an International Society for Asphalt Pavements symposium. Now, before you go scurrying off, consider what you'll be stepping (or rolling) on. Concrete production not only accounts for a surprisingly hefty chunk of carbon dioxide emissions, but it just sits there. Fortunately, ISAP is devoted to figuring out how asphalt can be more environmentally-friendly and serve as more than just a smooth surface. 

Rajib Mallick, an associate professor of civil and environmental engineering at Worcester Polytechnic Institute (pronounced "Wuster" or "Wista," depending on where you're from), took the symposium as an opportunity to present a concept he's been working on for the past two years with Novotech, Inc., an infrared and semiconductor technology company. Using an existing parking lot or asphalt surface, the new system would be installed during a resurfacing. A special piping network runs through the new pavement and as cool water runs through it, the water is heated and can be used for electricity generation. "The system cost is around $20-$50 per square meter and has the capability to generate up to 800 kilowatt hours a day six months a year in New England," Mallick says.

Since so many parking lots and roadways already exist, Mallick expects the solar collector costs to be orders of magnitude lower than the cost to produce traditional solar cells. Lab tests showed that the system can reduce the heat island effect commonly found in urban areas. Summer is quickly fading now, but I haven't forgotten the blistering heat radiating from New York City's streets. Next up for Mallick and his team: securing more funding and getting the concept off the ground. Or, rather, in the ground.

Photo: Model of a pavement slab with water-carrying pipes showing temperatures in different colors, courtesy of Rajib Mallick.

Comments

[Jonk]

This is FANTASTIC – we need so little room really to harvest solar energy – just the confidence to back this new (well actually very old !) energy source.. We can all help to make wise climate change resource decisions – read the emergency triage response to current climate change crises at www.cimatechangetriage
ActonClimate

[Jonk]

This is FANTASTIC – we need so little room really to harvest solar energy – just the confidence to back this new (well actually very old !) energy source.. We can all help to make wise climate change resource decisions – read the emergency triage response to current climate change crises at www.cimatechangetriage
ActonClimate

[bluedoctor]

I can understand this argument in the summer, but what about the winter? Also would these pipes be tougher than traditional piping? B/c before sinking a ton of money into this type of operation I would be pretty hesitant if we're putting in vulnerable components.

[Larch]

This research was done "in a lab" and does not address the issues of live loads (wear and tear from vehicles) and other physical & environmental stresses on the system (chemical de-icers, freeze/thaw cycles, etc).

The sustainability of emerging technology must be considered on 3 fronts: economic, environmental, and social. Consider that many regulatory jurisdictions require the provision of "functional landscapes" with canopy trees in landscape islands and buffer strips in and around parking lots to provide not only shade and screening, but biologic bioretention stormwater management systems to mitigate impacts of large expanses of impervious pavement. Do we cut down the trees in order to maximize solar exposure on the asphalt? I don't think so.

I applaud the concept- but the challenges of bringing the "proof of concept" down to practical and sustainable application has some ways to go. This is not meant to discourage those who are thinking outside the box from finding better ways to do things - we need more innovation to solve the problems that face us. I hope others on the blog might do some brainstorming to help this research find its way to the ground in a form that is practical and sustainable.