ENERGY FROM THE STREETS

The Road Energy System was originally developed to cut road maintenance and costs. A flexible pipe lattice-work grid is laid under an asphalt road. The sun heats the asphalt, which heats water run through the pipes. The water is pumped into a holding pool deep underground where the natural insulation of the earth keeps the water at about 68 F. In the original concept, the warm water was pumped back up to warm and de-ice winter roads. Now it is pumped through the walls and floors of buildings, heating them.

The process doubles the cost of construction, but it was economically viable when it merely extended the life of roads. Imagine how economically advantageous it is in a world with $100/barrel oil and caps on climate change-inducing greenhouse gas emissions. Pipe and pump building installation and supplemental heating is twice the cost of a normal gas system but it cuts energy consumption dramatically and generates half the emissions.

Similarly cooled water can be moved from underground pools to cool buildings during the summer.

click to enlarge

New energy uses from asphalt
Arthur Max, December 31, 2007 (AP via Yahoo News)

WHO
Civil engineering firm Ooms Avenhorn Holding BV

WHAT
Ooms Avenhorn is conducting test projects of the Road Energy System, siphoning the sun’s heat from asphalt-covered driving surfaces to heat homes and offices. One Road Energy System project draws heat from 200 yards of road and a parking lot to heat a 70-unit 4-story apartment building and another draws heat from 36,000 square feet of pavement for a 160,000 square foot industrial park. A third draws heat from a Dutch Air Force base runway to heat a hangar.

Schematic: How it works. (click to enlarge)

WHEN
- The concept is 10 years old but the pilot projects are now ongoing.

WHERE
- The apartment building is in the northern Dutch village of Avenhorn.
- The industrial park is in the Dutch city of Hoorn.

WHY
- The sun is the single most abundant and predictable source of renewable energy, delivering more watts to the earth in one hour than the world consumes in a year.
- Solar is only 0.04% of the world’s energy supply but photovoltaic cells are rapidly becoming more efficient, reducing the cost. Solar thermal plants are being developed, as are theories of how to store solar energy. Advocates expect solar energy consumption to grow.
- The principle is very similar to solar hot water systems.

Finishing up a roadway. (click to enlarge)

QUOTES
- Patrick Mazza, Climate Solutions: "…solar falls everywhere…solar comes out as the one [renewable energy] with the real heavy lift. It's the one we really need to get at…"
- Lex Van Zaane, Ooms Avenhorn Holding BV: "We found we were gathering more energy in summer than we needed, so we asked a building contractor what we can do with the extra energy…"
- New Scientist: "The prospect of relying on the sun for all our power demands is finally becoming realistic…"