Air Date: Week of May 30, 2008

Workers underlay pavement with a network of pipes that will carry water, warmed by the sun, to heat houses in the winter. (Courtesy of Ooms Avenhorn Group)

Dutch scientists have figured out how to harness the sun as it beats down on hot highways - cutting heating and road repair bills. Annie Jia reports.

Transcript

GELLERMAN: It’s Living on Earth. I’m Bruce Gellerman. Just ahead: pedaling to the pits – biking to the lowest places on earth. But first, this Cool Fix for a Hot Planet from Annie Jia.

[COOL FIX THEME]

JIA: On a hot summer day when the sun’s beating down, some people say, it’s hot enough to fry an egg on the sidewalk.

But a company of civil engineers in Holland has come up with a new, and more practical, way to use the roadway to harness the sun’s heat.

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At nearly a dozen sites across the Netherlands, embedded in the pavement, lies a network of pipes. Water flows through these pipes and heats up in the summer sun. The warm water is then stored underground, where it stays hot for several months.

In the winter, the water is circulated through nearby buildings – homes, industrial complexes, even an airplane hangar – providing warmth.

After it chills, the water is pumped back underground, where it stays cold into the summer. On hot days, the now-chilly liquid provides the same buildings with energy-efficient air conditioning.

At one site, in the northern village of Avenhorn, a 200-yard stretch of road and a nearby parking lot supply a four-story, seventy-unit apartment building with half of its annual heat.

But it’s not just the buildings’ residents who benefit. In fact, this new energy system sprang out of efforts to cut road repair costs. The warm water flowing beneath the road’s surface keeps it from icing over, and so, protects it from the damaging cycles of freezing and thawing.

While the technology remains more costly than conventional heating, its developers believe rising fossil fuel prices will soon render it economical.

That’s this week’s cool – or, hot – fix, for a hot planet. I’m Annie Jia.