Ooms’ Road Energy Systems capitalizes on the large absorption of solar energy by asphalt’s dark surface (Photo: Ooms)

Dr. Arian de Bondt, an engineer who works for the Dutch building company Ooms, realized 10 years ago that the dark surfaces that help buildings absorb heat already exist on the Netherlands’ asphalt roads. Inspired, de Bondt created a system that uses the road just outside Ooms’ headquarters in Scharwoude to heat the company’s buildings, reports The Economist.

The system, part of the Road Energy Systems, consists of a layer of asphalt concrete containing a closed network of pipes that are connected to underground aquifers. In summer, the sun heats the asphalt concrete pavement, which in turn raises the temperature of the water in the pipes. The water is pumped to a natural aquifer 100 meters down where heat exchangers wait to transfer heat from the pipes to the groundwater. Here, the heated water is stored for several months.

In winter, water is again pumped through the heat exchangers, but this time to pick up heat stored during the summer. This warm water is sent first to Ooms’ buildings, where it’s used for heating, and, second, under the adjacent road where the residual heat helps keep the road surface fee of snow and ice. The now-chilled water is then sent deep underground, in a separate pipe, to a second aquifer. Here, heat exchangers use the chilled water to cool waiting groundwater, which is stored until summer and used to cool the Ooms campus.

The result, Ooms says, is cheap heating in winter, cheap cooling in summer and CO₂ emissions 50% lower than conventional heating systems.

• Read more about Ooms’ Road Energy Systems (PDF, 339 KB)
  
• Read about a condenser chilled water subsystem in Flex Your Power’s Best Practices Guide for Commercial Office Buildings