After a search of “piezo” in the halfbakery, I almost chose not to post this…but what the hell, into the breach I go. Piezo-electric circuits are used in many applications in which pressure can be turned into a small electric current. My idea would be to layer sheets of piezo-electric materials within the composite materials used for building highways during road construction. The sheets could selectively be placed in high traffic areas, or could be continuous laminates in long stretches of road. As traffic passes over the sheets, the weight of the vehicles would press down on them, turning some of this downward force into electrical energy. For any individual vehicle in any small section, only a small charge would be emitted, but multiply this by thousands of vehicles which may pass over a stretch of road, and the resultant charge could be large enough to store for emergency roadside use, or could be used to power highway lighting. These piezo electric sheets could be connected to the reinforcing steel (rebar) in the concrete of the road, and turn the rebar into heating elements, de-icing roads during ice storms or cold conditions. Another use for this kind of cold weather road toaster would be on airport runways, in which the jet traffic itself would help keep the runways clear of ice.
-- rogerdna, Jan 09 2004

Piezo-electric tutorial http://www.morganel...om/piezoguide1.html
[rogerdna, Oct 04 2004]

Galloping Gertie http://www.ketchum....tacomacollapse.html
The ideal road surface. [Laughs Last, Oct 04 2004]

Just add these sheets during new road construction, so that over time, larger and larger sections of road would be treated. Or during regular road repair, add small sections at a time. The effect would be cumulative.
-- rogerdna, Jan 09 2004


I have read a synopsis recently for sidewalk tiles designed to generate electricity. I can't find which publication had the mention but it was in a recent issue of Popular Science or Popular Mechanics, I think, perhaps Dicovery. I'll try to find a link for you, [rogerdna].

By the way, does your name infer roger's 'dna' by chance? ;) Welcome to the halfbakery.
-- Tiger Lily, Jan 09 2004


We could have used this during the recent snow & ice storm here in the Pacific Northwest. Do it!

I see six annotations before mine, but 0 votes. What's up?
-- mack2, Jan 10 2004


aside from the scary fact it may encourage _more_ stinkin traffic, i think its absolutely brilliant.
-- mapgrrl, Jan 10 2004


Even though the energy to actuate the piezo elements is "free", it still seems inefficient.

If, instead, the weight of passing traffic were used to move small pockets of fluid that would drive small turbines to generate electricity, I think efficiency would be greatly increased.
-- Guncrazy, Jan 10 2004


Any movement in the road surface would increase the rolling resistance experienced by the vehicles. So this is not free energy as it comes from the vehicle fuel.

Vehicles waste most of their energy in heat via the radiator and hot exhaust, if that could be captured to heat/ de ice the roads that would be effective recovery of otherwise wasted heat.

A possibly more efficient way of getting the same result would be to tax the motorists to pay for road de icing, but I think that is thoroughly baked!!! :-)
-- KiwiJohn, Jan 10 2004


Any energy you could get would come at the expence of the engine working a little harder than it would if the generator wasn't there. This would only be practical if it were at the bottom of a very large hill.
-- thelambs, Jan 10 2004


Thanks for the welcome, Tiger Lily. "rogerdna" does refer to "roger's dna," but not by chance---by fiendish design. OK, not by fiendish design, by mundane accident of birth.
-- rogerdna, Jan 12 2004


Even though it doest seem like it, the road does deform under a passing car. The deformation of the road is wasted energy. Piezo electrics respond to very small deformations to generate electricity. This would not result in the engine working harder. Its a very good idea.
-- kracker, Jan 12 2004


I could swear we've done this before.
-- silverstormer, Jan 12 2004


Would haveing Peizo crystals in the road surface make it softer ?, if it did the road would wear out faster and you'd lose any economic benifit quickly.
-- SystemAdmin, Jan 13 2004



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