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 free 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.

• If we increase tree planting along the roads they may not capture enough sun (maybe Alexander Parade would?)
• The technology is new, has not been used in Australia (as far as I know), and there is no information about it's effectiveness in our context
• It relies on having an underground aquifer in the right location, although you could probably use insulated underground water tanks instead
• It would be quite expensive to install as a retrofit (certainly too expensive without reliable figures about cost & energy savings), although it would be worthwhile considering in new developments, or if major roadworks are being undertaken anyway.