Harnessing Energy from the Road

[rasperas]

With all these cars traveling at high speeds down our highways and streets, it could be very well possible to incorporate a piezoelectronic device into the tar, and rig it to provide power for the city, stop lights, and/or traffic signs. Any ideas on it?

 

[megashawn]

Hmm, seems like it would work, but I would wonder if it would provide a good enough output. Maybe if the device was under every square inch of a busy highway??

I was curious if one could setup some kind of windmill on the sides of interstates. I know semis just about blow me off the road. Seems it would work really well in places where the interstate is cut out in the middle of a forest. Trees on both sides would help concentrate the wind forward, right?

 

[chroot]

You can't beat thermodynamics. Any energy collection device that robs energy from cars would just force the cars to use more energy in the first place.

Perhaps the waste heat could be better used, though.

- Warren

 

[russ_watters]

Perhaps the waste heat could be better used, though.

- Warren

However, as Megashawn said, there's probably not enough waste heat to make use of.

 

[zoobyshoe]

Chroot is quite right about the notion of incorporating piezoelectric devices into the tar meaning that the energy is coming from the cars.

But, since cars are already losing energy to tar, any piezo electric devices that were incorporated that didn't make them use any more energy than they are already expending would represent successful energy recycling.

Would the cost to research and implement it be worth what you recover? I dunno.

Piezo electric wafers are getting better:

Innovation (November/December 2000)
Address:http://nctn.hq.nasa.gov/innovation/3-tt-wiggle.html

A few years ago I read an article where they were kicking around the idea of incorporating wafers into various parts of the car that are undergoing stress and vibration anyway.

They were also talking about the notion of setting up, not windmills, but arrays of wiggle vanes on the sides of highways that would transduce the wind created by passing vehicles into electricity. They thought there might be a way to use it to light the highway.

 

[enigma]

A buddy of mine is thinking doing graduate research into using piezo-like smart structures to harness vibrations in rocket engines to provide power to run the turbopumps. This would lower fuel requirements by a few percent.

I don't see any reason why using piezos to power nearby devices wouldn't work in theory.

In reality, cost is a major detrement. Hysteresis of the material is another. Asphalt gets really hot which quickly degrades most smart materials. Galfanol is one type which has better properties, but R&D is in the very early stages.

 

[PRyckman]

Do the piezoelectric wafers also turn kintetic energy into electric?
If the cars are already being slowed by the tar, as long as it is not slowed anymore it would be effective to use them. Also, how about in the floors of amusement parks or malls? The combined force of all the people walking would be large aswell. To use it in target areas only line up areas would be used.

enigma your signature says that there are always multiple right and wrong answers. but in more words
I read the rest of the quotes he has in there though, i agreed with most of them.

 

[russ_watters]

Do the piezoelectric wafers also turn kintetic energy into electric?

I did my senior design project for THIS company, which makes piezo sensors. They are polymers: plastics. Stretch them and a voltage is created. Apply a voltage and they deform.