Asphalt Energy

Tom Konrad is an Analyst at Alternative Energy Stocks, where he writes about investing in renewable energy and energy efficiency companies.  This article is a guest post for Jetson Green.

The December 6 Technology Quarterly from The Economist profiles a Dutch office building that is both heated and cooled using heat (or cold) from the asphalt of the road outside the building, as opposed to the more conventional use of solar thermal panels on the building’s roof.  The article optimistically ends:

The result is cheap heating in winter and cheap cooling in summer. And there is a bonus. Summer heating softens asphalt, making it easier for heavy traffic to damage the road surface. Dr de Bondt’s system not only saves electricity, but also saves the road. Expect to see more examples of it, in other countries, soon.

While this is a very elegant solution, the author fails to grasp that, because the road is essentially an unglazed thermal collector, and only gets warm in the summer or cool in the winter, requiring that seasonal heat be stored.  Summer heat from the asphalt is used to heat the building in winter, while the chill of the inter road cools the building in summer.

In this particular case, seasonal storage is accomplished with heat exchangers placed in not one, but two separate natural aquifers near the building.  The fortunate proximity of two such aquifers is extremely rare.  While this is a very elegant way to heat and cool a building, the lack natural aquifers in which to store seasonal heat will likely prevent widespread adoption of this technology, no matter what the author believes.

++Energy from Asphalt for Heating + Cooling Buildings [PDF]