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Would you give her the prize?

  1. Jul 10, 2017 #1

    CWatters

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  2. jcsd
  3. Jul 10, 2017 #2

    scottdave

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    At first it seems awesome. But I don't consider it renewable. The energy has to come from somewhere. It would slightly slow the car down, so the engine would have to burn a little more fuel to maintain speed. And how efficient are the piezoelectric devices? For each driver, the additional cost would be tiny. But if the device is cheap enough to install, it might be more economical for the city to use these to recharge signs, rather than solar panels( at least in areas which don't get a lot of sun). It could be worth a look.
     
  4. Jul 10, 2017 #3

    CWatters

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    I suppose it would be ok if only used say on the approach to a stop sign where a car would be slowing anyway.
     
  5. Jul 10, 2017 #4

    scottdave

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    Great point. Since they are slowing down, they would be braking (which converting the kinetic energy to heat).
    I have served as a judge on some science fairs. I always like to talk with the students to find out their understanding, and to give them tips on things they may not have considered. If I'd been judging this project, I would like to ask where the energy comes from.
     
  6. Jul 10, 2017 #5

    scottdave

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  7. Jul 10, 2017 #6

    jack action

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    Maybe the solutions of these kids won't solve the energy crisis, cure Alzheimer or help feed the poor, but if you require that type of criterion to be fulfilled to enter the challenge, how many 10-15 year-old (or anyone for that matter) would qualify for the challenge?

    I looked at some of the presentation videos from the finalists of this challenge, and I think it's more about the effort put in the research, the experimentation and the presentation. From the official rules:
    Knowing that inhabitat.com is convinced that her solution has potential, I guess that this 8th grader fully earned her points for Persuasiveness and effective communication!
     
  8. Jul 10, 2017 #7

    scottdave

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    I think the effort that she has put into this project is great. And she is a great communicator. I have no intention of crushing her idea. But I am saying that she needs to know where the energy is coming from, and how that affects the success of her project. I think she will go far, regardless of who wins the contest.

    Thanks for sharing the link to the contest. I am interested in looking at all of the finalists, now.
     
  9. Jul 10, 2017 #8

    russ_watters

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    I tend to agree; you can call it energy harvesting without calling it green/renewable. For a 13 year old, the idea doesn't need to be viable, but I think it sends a bad message to reward a claim that is just plain wrong in a basic way.

    Hopefully she'll learn the truth gently and not become a 30 year old still believing in (and trying to sell!) Santa Claus.
     
  10. Jul 10, 2017 #9

    jack action

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    I think the problem is those people who «scout» kid challenges to find solutions to complex problems. Especially if they believe and/or sell the solutions as to be viable.
     
  11. Jul 10, 2017 #10
    IMO, the 30% for Scientific Knowledge in an issue. There should be some baseline 'gate' for demonstrating sound science, or you get a zero overall. You could score 70% with a nice presentation on a perpetual motion machine. We have far too much of that sort of thing in the world today.

    My basic problem with this is she uses the term energy, but never discussed the energy being produced. Looking back, I did see she listed current with the different piezo she sampled (in fine print, and no dialog to bring attention to it), so around 1V and 6 mA for 6 mW. Fine for demonstrating the principal, but I cringe with the amount of hype between demonstrating an effect, and the leap to "cheap and easy" electrical energy production on the a scale of solving the world's energy needs! Don't tell me it is cheap and easy unless you have something to indicate that. And it does come across as 'perpetual energy' if you don't explain you are getting the energy from the cars (which might be fine, if as other's said, you are trying to slow the cars down).

    Too much to expect from 13 year olds? I don't think so. Start with a sound science principal and go from there. I think the "innovative, creative and presentation" focus leads to producing a generation of snake oil sales-men and women.

    I know it's not the goal of something like this, but I'd be more impressed with these kids demonstrating why a certain idea won't work. Build critical thinking. Show the difficulties of installing these in areas with snow and ice, what will happen when cars run over them, will they wear the car tires, etc. I remember learning the lesson that sometimes the most important thing is to know what not to do. I fear that all this positive reinforcement of everything a kid does is killing critical thinking.

    OK, I know I sound like a curmudgeon, but it is important. And actually positive, we need to be critical to make good progress, or we waste our time on the dreams that lead no where.
     
  12. Jul 11, 2017 #11

    scottdave

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    I think it would be cool to go to this contest and see the different projects and talk to the participants about what they are doing and what they may have forgotten to include. Hopefully to help them to improve themselves. I enjoyed judging at the science fairs. I have been a judge at both the Jr High (7-8 grade) and High School level. I have seen some good and some mediocre projects at both levels. I have also seen some Junior High projects which put some of the high school projects to shame. The website for the contest shows that there is some great thinking going on at this age level. It gives me optimism about our future.
     
  13. Jul 11, 2017 #12
    @ CWatters: Green and renewable as it functions every time the Piezo is subjected to pressure, which generates electricity.

    @ scottdave: The vehicle would not have to slow down or use more fuel as the Pressure pad would be mounted in the road surface, not on the vehicle, so that everytime a vehicle drives over it the pad will produce electricity.

    How much electricity would be produced will be dependent on the size of the pressure pad and how many Piezo cells would be mounted in it and how many pressure pads would be inserted into the road surface.

    I am currently working on a project that uses Piezo pads to operate switches.
     
  14. Jul 11, 2017 #13

    mfb

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    A coal power plant generator functions every time it is spun, that doesn't make it green or renewable.
    In general the vehicle will need more power. If the road gets pushed down by the wheel but doesn't return that elastic energy later the car will need more power to drive over the road.
    If you harvest vibrations, on the other hand, you can do that without increasing the car power.

    A main problem with all these ideas is their low power. If you have a device that can produce 1 W (that is a very large power for vibration harvesting) for 30 years, how much money can you spend on it to make electricity at a market-competitive price? Make a guess.
    About $5. Establishing the grid connection costs more already - a device that produces 1 W is simply not worth the installation even if the device and its power source are free.
     
  15. Jul 11, 2017 #14

    russ_watters

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    The way I like to describe this is that the car is constantly trying to drive out of a depression. So it looks like it is driving on flat ground, but is really driving uphill.

    And, of course: never forget conservation of energy!

    The key problem is this:
    Your unfinished logic process here is that the device doesn't need to move or deform for it to work. You're looking at the wrong side of the coin(or maybe just half?): it is the deformation, not the pressure, that causes the electricity to be generated.
     
  16. Jul 11, 2017 #15
    And at that payback, it would be better financially to invest the money elsewhere. As far as environmental payback, it's unlikely it would payback the energy/resources to construct and maintain it for 30 years. And if that's the case, it isn't 'green' at all - it's negative 'green'.
     
  17. Jul 11, 2017 #16

    JBA

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    We have had a similar discussion about power losses on this type of power generation and in both cases the issue that is being ignored is that the power loss driving over the hard surface of a piezoelectric plate is from a practical standpoint is essentially zero because the deflection of this type of device is comparable to driving on an existing concrete or asphalt surface so the equivalent power recovery is essentially 100%. At that point, the issue of power output then come into effect as to the economics of installing such a system vs. alternative power supply options.

    In the case of replacing a section of existing road where there is also an existing power distribution system there is one set of economics; however for a location that does not have either an existing power grid or road and the power generated is to be used locally to that point for applications such as safety lighting there is a whole different set of economics involved (not say that the comparable cost for alternatives such solar and/or wind power shouldn't be included in evaluating those cases as well).

    I feel many times we can make the mistake of taking a geocentric view applicable to our own developed environments when, in fact, those conditions exist on only very minimal region of the world's populations. Likewise, even small contributions to improving the environmental methods by which we generate power can, when accumulated, make an important contribution.
     
  18. Jul 11, 2017 #17

    mfb

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    Compared to the power of the car, the additional power the car needs is essentially zero. But compared to the car the electricity produced is essentially zero as well. It doesn't make sense to neglect a loss and highlight a gain of the same value (actually lower, because the conversion is not 100% efficient).

    These systems can be interesting if low power is needed at remote locations, sure. But connecting them to the grid doesn't make sense.
     
  19. Jul 11, 2017 #18

    scottdave

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    I don't recall her saying in the video that it was for developing countries, but the description on the contest page does mention that. So yes it can have some applications there. But I would like to see them stay away from terminology like renewable.
     
  20. Jul 11, 2017 #19
    You're forgetting something as it applies to something like the pizeo road concept. To focus solely on the locales that invention x is desired to be applied neglets the fact that frequently invention x will require production facility the likes of which exist on actually a vanishingly small proportion of the globe. There could be many reasons for this, resources or necessity of a modern economy for example, but it falls in line with what I always enjoy inserting into any discussion on solar...

    Tell me, if pizeoelectric roads were really that great a return on investment... is it likely that pizeo plate factories will be powered by the roads their employees drive to get to them? Or is this wonder product easily assembled in an afternoon with stuff out of the garage? Don't forget, coal power built coal power. It also built nuke. And hydro, and largely wind and solar. Essentially all the raw material, all the tooling, all the flourescent lights in the engineering offices owed to history's largest energy source. And in the current energy market it will be building a large share of whatever we end up going with next. So we really need to get serious about deciding which choice is worth it. Pizeo roads are not taking us in that direction, and nobody should be trying to lobby for them anywhere.
     
  21. Jul 12, 2017 #20

    JBA

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    There was also a time when the common knowledge was that neither wind or solar power would ever be practical. At this time, the best thing for us to do is continue to encourage and investigate all possible combinations of existing and proposed power sources, present and future, even if they are "not economical" at their current state of development.

    The idea that there can be a single best source of power for all regions of the globe is a folly. To paraphrase the President of GE Power Systems, "We cannot continue to depend upon our current centralized power production and distribution grids because they are too vulnerable to massive systemic failures. What we need is an array of interconnected distributed mini and micro grid power sources". Fortunately, due the current spreading development of solar and wind power around the globe that is exactly what is now happening; but, we should not assume that even those will the paramount systems of the future.

    Due to the spread of technological knowledge around the globe our rate of exponential technological growth and investigation will continue seeking new and innovative sources of power, even if some turn out to be deadends. The fluorescent lights mentioned above are good example of a deadend technology now being replaced by those once "little tiny low power" LED's.

    What we are now learning is that the once holy grail of lowest cost $/Btu basis for power sources does not necessarily represent their total cost once their damage to world health and environment are included in the equation.

    What was yesterday or is today is not what must or will be tomorrow.
     
  22. Jul 12, 2017 #21
    From all the replies posted to date only JBA has recognised what is proposed by the use of Piezo electrics to generate power which is renewable every time the piezo disc is subjected to mechanical pressure. The disc movement required to generate electricity is aprox. 0.1mm or 0.0039 in.
    The amount of power produced will be subject to the size of the disc and how many discs are included in a pad.
    Unlike Solar or Wind powered systems they are not restricted by weather conditions or lack of daylight.
    As to the limited power output, do you need a x Megawatt Coal / Nuke powerstation, not to mention the costs involved getting the power to a remote village maybe 1000 miles away, to power a few LED's?

    The idea is not to supply a power grid, it is to provide electricity on a very local level maybe down to a single dwelling just needing power for a few LED lamps.

    As to the pressure needed, most road surfaces are mallable and deflect when a vehicle rolls over it so it would not be a problem to incorporate a pressure pad in the road surface. In fact, russ_watters even made a reference to this point in his post about driving uphill all the time due to this "Deflection"

    For a young woman to come up with an alternative idea that could eventually provide power, even in a very limited form, in areas of the world which do not have any power at this moment in time is, in my opinion, certainly worthy of the prize.
     
  23. Jul 12, 2017 #22

    CWatters

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    If I've understood you correctly you are saying that the rolling resistance when driving over piezoelectric plates is the same as the rolling resistance when driving over concrete or asphalt?
     
  24. Jul 12, 2017 #23
    @ CWatters

    As the plates would be essentially "buried" in the road surface, the road surface would not alter the rolling resistance of the vehicle.
    In addition, even if there was a difference in the surface material the effect would be absolutely minimal and certainly not detectable.
    Rough Example: Car tyre surface in contact with the road surface = tyre tread width by length of tyre contact with road surface or numerically say 215mm x 180mm. For purpose of travel only the length is relevant 180mm. So a vehicle travelling at 70 kms/hr (43.5mph) will cover 70000 mtror 229658 feet., that extends to 70.000.000 mm or 2.755.905 inches in 60 minutes. In seconds that means the vehicle will travel 19444 mm in 1 second.
    If the pad was 720mm wide the tyre contact with the pad would be 0.037secs, as I stated earlier, not detectable and would not change the normal rolling resistance of the tyre to road surface.
     
  25. Jul 12, 2017 #24

    256bits

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    I think what you are saying is that the road/tire deform anyways and produces heat.
    The piezoelectric device is capturing the deflection of the road and making a capture of that energy as electrical, rather than having an increase in temperature of the road.
     
  26. Jul 12, 2017 #25
    @ 256bits,

    the Piezo device itself actually only needs a deflection of about 0.1mm which is enough to produce the electrical impulse. As roads deflect under weight of the vehicles passing over the surface, the movement required to actuate the device is a given fact. Temperature does not play any role in the piezo's ability to produce electricity. The deflection of the road surface is not producing any electrical power, it is only allowing the pressure required to be transmitted to actuate the piezo device.

    In order to clear up any misunderstandings, the piezo device is a composition of various components which normally form a flexible flat surface circular part with a plus & minus cable attached. The piezo is deflected from its normal flat status by pressure applied to the center which in turn generates an electrical current. When the pressure is relieved the piezo returns to it's flat state until the cycle is repeated. As most road surfaces are mallable they deflect when the weight of a vehicle passes over it, this deflection will allow a piezo device to function even when mounted below the actual road surface.

    On a side issue, I did some work last year on suspension systems where piezo devices are being considered as an on-board electrical source when mounted on the vehicle shock absorbers.
     
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