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Street heat

23rd August 2008

Copper pipes laced through hot city pavements could generate more electricity than solar panels

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Cities are hotter than the countryside, by up to six degrees Celsius due to the “heat island effect” caused by concrete roads and parking lots that absorb and retain heat. So why not put that heat to good use, says Rajib Mallick of Worcester Polytechnic Institute in Massachusetts.

Lacing asphalt with copper pipes, says Prof. Mallick, could create hot water or drive turbines to generate electricity. As well, the temperature of the asphalt would decrease, lessening the heat island effect at the same time.

Although the energy per square centimetre from asphalt would be less than that generated by rooftop photovoltaic solar panels, the sheer expanses of available asphalt would generate many times more power. And as roads typically need to be resurfaced every 12 years, there are ample opportunities to install the pipes relatively cheaply, costing between $20 and $50 per square metre.

“I’m not saying we should cover up everything with asphalt, but if it’s already there we can use it to create energy,” says Prof. Mallick, whose research was presented at the International Symposium on Asphalt Pavements and Environment in Zurich, Switzerland this week.

Published in The Green Report in The Globe and Mail

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• Energy
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• Research

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