DEC 17

The part that I wonder about is in climates where they normally have issues every freezing season of roads breaking apart wouldn't a road without a stable bed break apart even faster?

wouldn't the force of friction be the same, and gravity would be the main active ingredient?

I'd tend to agree with Treehugger. There's some deformation inherent in our current roads which causes inefficiencies and lost energy, but any additional inefficiencies they add would lead directly to more fuel consumption. If they're selling the energy back to the public afterwards, it is a form of robbery. On top of that, if cars are still burning dirty fuel are they the best way to power our homes?

sorry to post so close to another...but to continue the thought.

you would have the forward force of the car ontop of a paved surface, the piezo electric is underneath the pavement (assumed) So, I don't know if its robbery as otherwise your vibrations and downward pressure would be lost to the ground,...Here's a though it could possibly help the roadway by absorbing motion instead of sending it through the ground...

If the piezo would only absorb force generated downward and otherwise be lost to the ground. the surface itself isn't going to change. I would assume this is analogous to using the Co2 from a coal powered plant to feed algae, its a byproduct that is otherwise untapped. Also, .8 MW per mile is a fair amount of power.

Cars still run on Petrol... so wouldn't that still be fossil fuel energy? . . . of course we could take this argument further and point out that walking and biking is fundamentally fossil fuel based as well... some estimates say an average of 10 Kcal of fossil fuel energy go into the production and delivery of every 1 Kcal of food we eat... so piezoelectric dance floors may be even less efficient.

Even if it did increase friction there could still be many obvious areas where it makes sense. Downward sloping lanes after a mountain pass... Areas where a highway enters a city... Areas where the speed limit changes to a lower limit... Although you'd be taking away kinetic energy you'd be saving people's brakes.

This system(according to the company website) will only use energy that is normally wasted into the road surface. The only way a system like this could possibly reduce gas lileage is if the system increased the rolling resistence of the road surface which is highly unlikely since the piezo generators will not be in direct contact with the tires of the cars.

"it’s more important to have the clean electricity than worry about stealing something so unnoticeable."
Nonsense. It's not clean energy if it's tapped from a car powered by a petrol engine.
Also, if the energy stolen is "unnoticeable", then the electricity produced will also be "unnoticeable".
It won't give any more energy than what it stole from the car.

Overall, it's like a petrol generator, just more complex and less efficient.

CNCMike, rolling resistance is not the only way to tap into a car's energy.
It's the deformation of the road that is the cost here. Instead of being flat, the road is pushed downwards by the tire, which means the wheel is constantly going against a little hill.
That's how it slows the car down.

i think if you place it on a road that slops down hill, it would end the argument. This way you dont need extra gas to get over it, just let gravity pull down the hill. Coasting!!!!

A car with regenerative braking would be robbed of energy even on a downhill. And we'll all be driving such cars soon, right? By the way, the objections we're raising also apply to thowe schemes for car-powered wind turbines.

Heres a couple probable locations that it could be used that it would limit the downside of the friction:

1. Highway offramps
2. Extended downhill slopes, such as coming off mountains
3. Curvy roads that require frequent braking
4.Parking lots
5.Toll Booth access roads

piezoelectrics is NOT a SOURCE of energy in any place that the energy tapped into is used in any other way... cars being a good example LOL
I think, if it were to be a real energy source it would have to be a perpetuum mobile of the second type...

There is no system to "create" energy. In this case, all the energy that's "produced" by the piezos comes from the vehicles. And all the kinetic energy of the vehicles comes from burning gas. The more energy you extract (by having higher bumps, for example), the more energy you must "put" in the system (i.e. more gas). Being that internal combustion engines are highly inefficient, and being that the energy balance must be kept, this is not only stealing. It is also an extremely inefficient way of transforming gas into electrical power.

Several of you are claiming that it is not clean because it "runs on petrol." It runs on car movement, if the cars become electric then this objection is void. This would provide a source of clean electricity at the site of use and could allow for electric filling stations to use the road.
As for cost in using the road, I feel like it would have to be rather extreme to cost much. If a car gets 10mpg and gas is $4 (as it was recently), a mile costs $.40. If the road halved fuel efficiency for the length, it only costs $.40 to the driver, and halving efficiency seems extreme to me, and it could be considered a tax on using inefficient cars.
Additionally, if the car created "little hills" in the road it would break up the road, that kind of resistance seems unfeasible.
What if the electric companies were forced to maintain the road in use for piezo? That would pay consumers back in reduced taxes.

I have a question... where is this electricity going to go? How will it be used? And more importantly... if I'm helping generate the electricity on roads that my tax dollars have already paid for, using my car which I have to pay to buy and maintain... am I also going to have to pay for using the energy that I helped create? Or will I see a decrease in my energy bills?(basically will the electric company start paying me for helping them generate electricity?)

It just seems like it would be kind of sad to pay for the road, the car, the gas, and the electricity it generates.

Wouldn't that work much better at the bottom of a body of water or something? A large column of water weighs quite a bit.

It's the combination of the down and up that does it, not just the down, otherwise, yes.

Andrew,

Even if all the cars were eletric then there's still a problem. If you're using the kinetic energy of electric cars (powered by the grid) to generate electricity (via piezoelectrics) to pump back into the grid, then there will be a net loss (laws of thermodynamics) and the world will be the poorer for it.

The only justifiable use for this would be to power a warning sign or something like that in an off-the-grid area without enough sunlight or wind. Seems pretty silly.

I don't see a problem whether it matters if it's an electric car or a gas powered car. The fact is that both cars consume and don't give anything back. The new system by Innowattech changes this situation by getting something (energy in this case) out of natural resource consuming cars. So I view this project as a step forward.

As for still having to pay for the energy that we will produce with our personal vehicles, I think there is no problem here. As long as we are have agreed on paying for the energy produced from the Earth's resources we have no reason on refusing for the one generated by piezoelectric generators. Unless we are paying for the darn things from our money (which don't include the taxes we pay monthly).

If they called it highway robbery without actually knowing the numbers, then they're just complete idiots for posting a post without checking.

I am not sure if I get this right.

Roads, as far as I know, are not designed to flex. They are made as stiff as possible with the materials available. They are supposed to move with the weather, season, and temperatures, but not specifically to flex downward. Unlike a gymnasium floor for instance which is designed to absorb shock. A road should not flex downward because this will result in more of a dent under each wheel and more friction and therefor more fuel consumption. Adding a mechanism that gains energy from this undesired flexing can only work if you allow the road to flex more. If the same materials that are used to create a stiff surface are used above the piezoelectric elements that want to be flexed, the flexing can only increase. That means that the car rolls less efficiently. The piezoelectric elements do not use wasted flexing of the road, they make the road even more flexible.

It seems similar to putting a wind generator on your car's roof and create electricity with it. You slow down the car to create electricity. Or the whole talk about using your alternator to create hydrogen and increase the efficiency of your car.

As Oscaruzzo wrote, gasoline is burned to move the car. Some of this energy is used to flex the piezoelectric elements. This system results only in a gain if you make the rolling of the car more efficient at the same time.

Am I right?

Karsten
http://www.polluteless.com

I just asked the company for some numbers on the issue. Now, it's going to be 'tested' next month, so lets just wait on the numbers before coming to any conclusions on our own without the data to back it up. If someone can capture a huge percentage of wasted energy, then why not embrace the idea?

If it's like riding on a washboard, however, I'll be pretty turned off myself. I'll give them the benefit of the doubt before I see some test results, though.

This only makes sense in front of a stop sign where cars are guaranteed to be slowing down. Regardless of whether the cars are using petrol or batteries, it is going to take away kinetic energy from the vehicles. Taking away kinetic energy to generate electricity is fine if the vehicles are already trying to slow down (in front of stop signs), but is a net energy loss (by conversion inefficiencies) for areas like highways where vehicles are trying to maintain speed (kinetic energy).

Now if it is a remote area where they need electricity to say, run some road monitoring equipment (cameras, traffic/speed sensors, road temperature sensors, etc.) where there is no electric mains service, then this might make sense as an alternative to a solar panel, but again, just for capturing electricity it only makes sense at a stop sign (not even at a traffic light because traffic might be traveling through a green light and not stopping).

Interesting point wideize if its this affective surely it could be used in the sea where a cubic metre or two weighs the same as an average European car.

But surely this system is stupid other than as stated down hills etc. Otherwise electric cars could have a wire attached to the side of the road and help power themselves and speed themselves up, I cant see how it can produce energy at a gain other than hills/ slowing.

I'm a bit skeptical about the Innowattech concept too. Obviously the system shouldn't make the traffic use more energy. But there's more technology coming up, like piezo-electrically fed cellphones. They would charge their batteries on sound waves of the surrounding.

And for that I see a possibility in traffic, since there are many acoustic fences along highways. They are built to absorb energy in the first place, so why not use it to create electricity for streetlights or motorway signals?

Of course there's a long way to go to make these technologies economically feasible. Plus if they're building less and less noisy vehicles (EV's or Fuel cell driven) and roads, there's gonna be some more bottlenecks

Damo-

I'm aware of the law of thermodynamics, I was thinking maybe the force of gravity would be the added energy to make it not a loss?
I watched the company video, the premise seems to be that cars driving inherently warp/flex the road and all they are doing is putting stuff in the road to collect the already existing vibrations/weight/motions and convert them, not to create flexible roads. Additionally, the panels looked about 2 inches wide every couple of feet, so it's not like the entire mile of road is made flexible. My guess is the energy the car uses to break up asphalt and create potholes is the energy that's being harnessed, i.e. wasted energy not energy that would cost the driver additional money or violate thermodynamics, hopefully.
Also, 500kw is .5MW not .8MW, yeah?

One way or another, the car is going to losing energy due to the energy converted into electricity. As Ron suggested, place them on the down hill lanes.

Also, one note on the individual car loss being 'negligible'. Given that Hank (yes, I realize Hank didn't write the article) wants to reduce CO2, this would increase CO2 when you look at all the cars that traverse this vs. a regular road. While the individual cost may be small, the aggregate is going to be much more.

I would assume that a prototype would be built on top of the pavement for development purposes, however you sure wouldn't want the device itself to be the wear component. I would expect a real installation to be embedded under a wear component such as a layer of asphalt or concrete. The piezio-electric will generate power by distortions across it's surface area, thus the constant flexing by cars crossing it's face would do exactly that. Why didn't I think of that?

Undoubtedly, the weight of a car deforms slightly the asphalt surface of the road as it passes. Asphalt is not terribly hard, and it is quite flexible. Piezo electric generation works through pressure. The pressure is already there, the asphalt surface is already an excellent medium for transmitting that pressure, so why not use it rather than waste it, by placing piezo electric generating strips under the asphalt? I don't think it would create any extra drag at all on the autombiles. It sounds like a simple, and obvious adaptation of a century old technology to generate green energy. BTW, Einstein won his Nobel prize for his explanation of how the piezo process works.

Is 500 kw meaningful ? It would be helpful for someone to put an example to this.

500 Kw could power.......

I would think areas before stop signs,speed bumps, bridges, toll booths where traffic slows
to a stop may be good areas for this.

I like the ideas of using this device in places where the car is slowing down (downhill, stop signs/lights, etc), but what about harnessing people power? The sidewalks in Times Square could be used to help power all the lights that draw all those people. The difference in walking energy will surely be negligible. (beside, more exercise would be a good thing!)

You should think about this thing as an embedded device in between the road surface layers. They should design the layers anyway to be usefully drag resistant and water resistant and rigid, but not too much rigid, nicely black, but white in some areas... So you have to DESIGN a road surface sandwich to make a good road. Still this would have resonancies while cars passing by. Capture those vibrations while leaving all other parameters fixed and you get the "free" energy which otherwise would be lost.

Go and walk onto the closest bridge to you and you will feel the bridge itself vibrates as big cars are rumbling onto it. Now capture those vibrations and make electricity. You not only capture the energy, but also implemented a nice vibration dumper too.

There is nothing wrong with this, if designed properly.

I completely agree with Karsten :
a layer of piezoelectric below the asphalt
would make the road more flexible than it already is,
so the car will lose more power than on a normal road, and it's only that additional loss that will be (partially) recycled.
The normal road power loss will still be there.

Regarding the energy loss to vibrations and damping,
wouldn't it be simpler to make the car suspension's damper recycle it, rather than the road?

Car dumper: Long distances, big forces. No place for piezo.
Road surface: Very short distances, big forces. Extremely good for piezo.

Different car bumper to capture energy: very expensive stuff.

Cars burn gas to drive. Driving makes electricity. Therefore, gas --> electricity, and yet you call it "clean electricity"? Please put down the crack-pipe and read the 1st law of Thermodynamics.

I suspect this is a bogus company, as the numbers don't add up. They claim 500W per meter-- that's incredibly high both compared to rolling resistance (maybe 10%), and how much energy can be extracted from a peizo-generator. Now look at the cost/W -- way more just for the crystals compared to PV, etc. It would be more practical to put solar panels along a sound wall of a road.

It would be more interesting to do research on paving material that reduces rolling resistance, rather than this scheme that increases rolling resistance (like walking on sand.)

I liked the idea of recovering energy at stop signs. We could have cables like on aircraft carriers that slow down the cars and truck and generate energy.

Remember that road induced vibrations are already siphoning energy from vehicles. (That tremmor you feel when a semi-truck rolls by requires energy to produce). The plan is to convert the enegy being wasted shaking the ground into useful energy. The usefulness of the tech depends on how efficently the can reduce the rumble without causing too much extra work for the cars. If for instance for every watt of energy "siphoned" from cars, we can produce 3 watts of electricity, this is probably a good thing (depending on economics of maintenence and installation). If you are only getting 1 watt of electricity or less for every watt siphoned this is bad as there at best no net gain.

Conservation of energy is a pretty simple concept-if you generate energy, you take it from somewhere. This energy source is one of the most dirty imaginable, since it is, by definition, dirtier than the cars and trucks that generate it.

500kW/km ~= 800kW/mi = 0.8MW/mi, not 8MW/mi.

Frankly, this does not particularly make me trust the math given in the article.

Those places could definitely use this technology.

Anyway, this would be good on downhill sections of road where people are going too fast anyway or before corners which require braking.

Unless you're aligning the piezo strips PERPENDICULAR to the surface of the road, in order to catch the longitudinal deflection of the road surface in the direction of travel, then the energy you're extracting is NOT due to drag on the vehicle. If you're installing the piezo strips in the far more likely configuration UNDERNEATH AND PARALLEL TO the surface of the road, then the energy you are extracting is due to the pressure applied to the pavement by the weight of the car.

If we assume that a typical car weighs 1000kg(2200lb) and is 3m long, then you can fit 333 of them in a kilometer, or about 530 in a mile, packed bumper to bumper. Each of these cars contacts the road twice in those three meters, for a total of 220 pressure points per kilometer. In order to transmit one joule of energy to the road surface, each pressure point, bearing a weight of 500kg, would have to deflect the road surface by 2mm, which strikes me as quite a bit of strain for a piezo transducer.

Assuming for the sake of argument, though, that the piezo beams can deform by 2mm over their length, then a fully loaded kilometer of roadway would yield about 222 joules. If each piezo is struck once per second, that's 222 W/km of energy transferred to the surface of the road.

Each point of the road being struck once per second is equivalent to each vehicle moving 1.5 meters/sec, or 5400 m in 3600 seconds, or 5.4 km/h.
We can assume that the cars are moving maybe as much as ten times faster, but if you do that you have to assume you have many, many fewer cars.

Realistically speaking, even if the cars are only moving 3MPH, they have to have SOME distance between them. Assume that there has to be three meters of space between each vehicle and the vehicles ahead of and behind it. This halves your yield to 100 W/km, and that's still assuming 100% conversion of road deformation to electrical energy, which is clearly ridiculous. Probably even 10% would be excessively high.

In other words, the claim of 500 kW/km is pure, 180 proof bullshit.

I like your maths but does it say in the article that 500 kW/km es produced in an hour, a day, a month, year? does it say that it´s calculated with an average of 100 vehicules per hour? or 10 vehicules? ... we need more numbers.
And people please it´s good that you know the laws of thermodynamics but you also have to know when to applied them. This just collecting lost energy (like solar panels if you like).

The energy source tapped in this case would be lost otherwise to heat the street (that's what friction does).
It will simply increase the amount of energy received from petrol.
It is increasing fuel efficiency!

The enormous collective kinetic energy of motor vehicles, especially long-haul trucks, currently goes into the degradation of roadways, requiring constant, and expensive maintenance. This piezoelectric concept would recapture some of this huge energy flow. Another concept, Solar Roadways, http://www.solarroadways.com/, would transform roadways into dual-use solar panels, placing the cells beneath tough transparent plastic, developed as body armor for defense applications. Like other alternative energy concepts, it would require large upfront investment, utilizing intelligent, self-monitoring, "smart grid" electric networks, introduced incrementally. These concepts invert the underlying idea of a classic Robert Heinlein science fiction story of 1940, "The Roads Must Roll" http://en.wikipedia.org/wiki/The_Roads_Must_Roll, where the roadways are giant conveyor belts, run by huge motors - cheap, virtually unlimited energy is taken for granted. In our world of 2008, staring down the lee slope of peak oil, the motors become generators.

Did anyone read the FAQ on their site?
============================================
Doesn’t placement of the piezoelectric generators within the layers of the carriageway hurt the quality of the road?

Innowattech’s technology does not affect the quality in any way. The generators are placed under the upper asphalt layer. The generators possess the same elasticity as the asphalt, and therefore, provide the same resistance to the wheels as asphalt.

Every time I read about this subject I get tickled at the responses I read. I am amazed how many people have an opinion and state it so passionately and promote their belief as to be factual and indisputable. Not one person has produced any evidence to their claims as to why it will or why it will not work as described by the inventing company.

The way I see it is pretty simple. Its all speculation here. The only factual statement I believe to be possibly true is the applications on a grade or in an area where braking will occur. The application of on level or inclined surfaces would require a lot more information be made available about the characteristics of road construction materials and the the piezoelectric generators construction as well.

One person attempted to do the math as to the potential energy output of the system being describbed. Unfortunately I feel there is absolutely no way to do this. I have read many articles on innowattechs project and find several different versions of their planned project. First notable point is total meters involved. I read some places that via direct interview with the inventor the claim is one hundred meters of four lane road. In other places I read one meter of four lane road. In another I read one meter of two lane road.

There is no way to form an opinion of any substance without knowing the facts. I can safely say that anything I have to say would be nothing more than pure speculation. I would be embarrassed to even give one without factual data first.

Piezoelectric generators can be stacked there is absolutely no way to predict the capability of this project without all pertinent data as to the construction of their generator.

Most of you are arguing the laws of thermodynamics. I ask you this as a simple question. What knowledge do you have as to the current characteristics of paving ISO standards? As far as I know the piezoelectrics might improve the roads flexing strength not degrade it. I have no knowledge as to which is less efficient. Pavement or pavement supported by a piezoelectric generator. It is just as feasible that the generators could actually stiffen the pavement.

In my opinion only there is not enough data available to be stating anything here at all.

hmmm.... stealing... thats hard to say. if u kno they will be taking it as u pass, and u have a problem with it then dont pass there.