Traffic Energy Capture (Harvesting)

bigfellla · 4th July 2012, 8:06 PM

Ok, guys i have been in contact of a couple of academics at the CSIRO on energy harvesting from traffic.

The company I work for operates and maintains many of the major transport networks in Australia.

I am looking for ideas and comments on the latest energy conservation and recovery techniques.

I have 15 years experience in energy physics and conservation, but things like peizio-crystaline road surfaces are new to me.

Comments and references appreciated!

orcone · 4th July 2012, 8:25 PM

Road-rage powered pedal system to charge the battery.

I also have no idea what you're talking about.

mtma · 4th July 2012, 8:55 PM

He's talking about a proposal that surfaced in the recent years which suggested to use piezeo elements (and some other possibilities) embedded into the roadways to generate electricity from the alternations of the mass of the vehicles as they move along.

There was also a dance floor somewhere in Europe which generated electricity to power the party based on the same concept.

The merit of the system is questionable, because if you identify the source of the energy you will lead yourself back to the ICE in the vehicles travelling on the roads. You are in fact taking energy away from the cars (the cars would require more effort to traverse a road made to generate electricity in this manner) which means that you're taking energy away from one of the most thermodynamically inefficient sources of fossil fuel energy in common use today. Put simply, it would be better to have generated the energy from a coal plant en masse once you're done with it.

There are certainly some outs if you used generator materials with some form of dynamic property that you could control. You are probably far better off identifying techniques that will recover the suns' heat from the road surfaces than mechanical regeneration from the vehicles.

Another way to think of it, cars are designed to roll. To recover energy by modifying the surface of the road, you need to inhibit their rolling. This can't be achieved to any meaningful effect without substantial modifications to the surface properties (effectively you would want your road to turn into something like foam) but the road can't be that soft all the time if you want to 'regenerate' the kinetic energy of the vehicles braking only. At present the only practical compromise is to have a hard surface similar to the current road surface, generate only a fraction of the energy lost by braking and generate energy when the cars aren't in need of braking as well. Effectively you're not gaining anything at all.

At the moment the practical openings for effective traffic energy regeneration are on the vehicle itself - from a system perspective roads infrastructure would have much more energy to save from devising a system to remove the need for cars to brake during their journeys in the first place.

the3coopers · 4th July 2012, 10:33 PM

Quote:

Originally Posted by mtma

You are in fact taking energy away from the cars (the cars would require more effort to traverse a road made to generate electricity in this manner) which means that you're taking energy away from one of the most thermodynamically inefficient sources of fossil fuel energy in common use today.

Ahhh - but it would work awesomely well on steep hills. Better you taking the energy, rather than it being turned to heat by the brakes.

If you used decents sensors, you could even slow down travellers before they got booked by speed cameras

mtma · 4th July 2012, 11:18 PM

Quote:

Originally Posted by the3coopers

Ahhh - but it would work awesomely well on steep hills. Better you taking the energy, rather than it being turned to heat by the brakes.

If you used decents sensors, you could even slow down travellers before they got booked by speed cameras

Unfortunately regeneration performance on slopes is then limited by the ground clearance of the vehicles - which limits the maximum amount of braking force that you can possibly resist on a slope from the surface alone - analogous to the same problem whereby you need a larger chock to stop a car on a slope than a flat - you need to resist the rolling at a certain angle with respect to gravity but only a small portion of the tyre is actually available for you to do so.

Not to mention this is with a perfect magical energy generating foam-cum-gel material - practical materials will have significant fatigue limits which would need to be kept in mind.

The energy gained from a decline would be much better used so that the engine doesn't need to be revved and the hydrocarbons burned in the coming incline (at 20-30% thermodynamic efficiency too) - which leads to on-vehicle regeneration being a significantly better idea.

For reference a power plant would gross well above 45% thermodynamic efficiency (up to 60% on a combined cycle plant) - that's conservatively 50 to 100% more efficient than what can be achieved by the engine in a car.

Widman · 5th July 2012, 7:55 AM

TJANSTAAFL

LINUX · 5th July 2012, 5:13 PM

From what I've read energy harvesting techniques aren't being developed as sources of large amounts of power. Typically they seem to be implemented in remote electronics to remove the need for batteries/solar panels/etc.

For example someone at the Newcastle CSIRO (I think it was Chris Knight, maybe you've talked to them?) developed a system which generated electricity from trees swaying in the wind in order to power remote weather stations. Another system I read about used traffic induced vibrations on a bridge to power monitoring electronics (strain guages, wireless link, etc) so that somebody didn't need to climb the bridge periodically to change batteries.

Further reading (which you may have already seen): http://www.csiro.au/en/Outcomes/Ener...sor-nodes.aspx

bonox · 5th July 2012, 5:46 PM

what's the strain of the crystal like?

If it's down in the less than 1% bracket, then it's not really imposing a more significant impediment to movement of the vehicle than a roadway is already.

Obviously, as you compress the crystal, you need to apply effort to climb onto the next one, but you already do this with asphalt/concrete/dirt/grass anyway. That being the case, you really do have a money for nothing scenario, since the vehicle passing over the surface isn't having to provide more energy that was being lost to the roadway/tyre deformation anyway.

As crystal strain increases, this becomes less and less true to the point where it's like driving in sand. From my brief knowledge, piezo-electric crystals have very low strains anyway, so I can see how this might work in practice.

Special large strain units are still only ~1-2%
http://www.physics.montana.edu/eam/highstrain/

so it stands to reason more traditional units are smaller and if layed as thin membranes, your vehicle climb is practically insignificant compared to standard layered pavement

http://www.scribd.com/doc/13274376/S...halt-Pavements

bigfellla · 6th July 2012, 10:31 AM

Yes it is Chris that I am speaking with. Interesting stuff. I am meeting up with him shortly.

Bastard Child · 6th July 2012, 1:12 PM

Set induction coils in the ground and rob passing vehicles of some velocity

Or this http://livepaths.brinkster.net/livep...?contentid=888

oculi · 6th July 2012, 1:36 PM

Quote:

Originally Posted by bigfellla

Ok, guys i have been in contact of a couple of academics at the CSIRO on energy harvesting from traffic.

The company I work for operates and maintains many of the major transport networks in Australia.

that's nice, why don't you focus on fixing the pot holes and traffic first?

what levels of power are you looking at generating? what are you wanting to power? you could only really capture energy when vehicles are going downhill as mentioned or when vehicles are braking as otherwise you are just forcing people to buy more fuel which is stupid.

Huggy_Bear64 · 6th July 2012, 5:45 PM

Quote:

Originally Posted by mtma

The merit of the system is questionable, because if you identify the source of the energy you will lead yourself back to the ICE in the vehicles travelling on the roads. You are in fact taking energy away from the cars (the cars would require more effort to traverse a road made to generate electricity in this manner) which means that you're taking energy away from one of the most thermodynamically inefficient sources of fossil fuel energy in common use today. Put simply, it would be better to have generated the energy from a coal plant en masse once you're done with it.

There are certainly some outs if you used generator materials with some form of dynamic property that you could control. You are probably far better off identifying techniques that will recover the suns' heat from the road surfaces than mechanical regeneration from the vehicles.

Another way to think of it, cars are designed to roll. To recover energy by modifying the surface of the road, you need to inhibit their rolling. This can't be achieved to any meaningful effect without substantial modifications to the surface properties (effectively you would want your road to turn into something like foam) but the road can't be that soft all the time if you want to 'regenerate' the kinetic energy of the vehicles braking only. At present the only practical compromise is to have a hard surface similar to the current road surface, generate only a fraction of the energy lost by braking and generate energy when the cars aren't in need of braking as well. Effectively you're not gaining anything at all.

At the moment the practical openings for effective traffic energy regeneration are on the vehicle itself - from a system perspective roads infrastructure would have much more energy to save from devising a system to remove the need for cars to brake during their journeys in the first place.

Quote:

Originally Posted by oculi

that's nice, why don't you focus on fixing the pot holes and traffic first?

what levels of power are you looking at generating? what are you wanting to power? you could only really capture energy when vehicles are going downhill as mentioned or when vehicles are braking as otherwise you are just forcing people to buy more fuel which is stupid.

One can assume that the road is already being compressed by vehicles driving over it. There would also be vibration and heat energy just being dissipated by the road surface.

Any of these could probably be harvested if you had the right materials and you would add no more rolling resistance to the road (unless you add the induction coils, although that would be pretty hilarious).

mtma · 6th July 2012, 6:20 PM

Perhaps my elaboration has obscured my point.

My current view of the problem is that you are attacking the (metaphorically) 2% side of the problem, when in fact you could be addressing the other 98% with substantially less effort and substantially greater results.

I don't have all that much problem with the theory - for reasons of utility it's in fact quite effective for say the measurement equipment mentioned previously - it's just from a useful 'energy recovery' perspective it currently doesn't make sense to do it against other possibilities.

It's one of those things that it's nice to keep your hand warm in research with but it's going to be decades before it's going to be meaningful, or it might even stay forever a niche product.

Perhaps the good work they've been doing at CERN will reveal some magic much quicker that I might expect, but that's also true for every other element of energy generation, transfer and use.

4th July 2012, 8:06 PM	#1
bigfellla Member Join Date: Oct 2011 Posts: 169	Traffic Energy Capture (Harvesting) Ok, guys i have been in contact of a couple of academics at the CSIRO on energy harvesting from traffic. The company I work for operates and maintains many of the major transport networks in Australia. I am looking for ideas and comments on the latest energy conservation and recovery techniques. I have 15 years experience in energy physics and conservation, but things like peizio-crystaline road surfaces are new to me. Comments and references appreciated! Last edited by dakiller; 4th July 2012 at 10:51 PM. Reason: Please, no allcaps in titles

4th July 2012, 8:55 PM	#3
mtma Member Join Date: Aug 2009 Posts: 2,601	He's talking about a proposal that surfaced in the recent years which suggested to use piezeo elements (and some other possibilities) embedded into the roadways to generate electricity from the alternations of the mass of the vehicles as they move along. There was also a dance floor somewhere in Europe which generated electricity to power the party based on the same concept. The merit of the system is questionable, because if you identify the source of the energy you will lead yourself back to the ICE in the vehicles travelling on the roads. You are in fact taking energy away from the cars (the cars would require more effort to traverse a road made to generate electricity in this manner) which means that you're taking energy away from one of the most thermodynamically inefficient sources of fossil fuel energy in common use today. Put simply, it would be better to have generated the energy from a coal plant en masse once you're done with it. There are certainly some outs if you used generator materials with some form of dynamic property that you could control. You are probably far better off identifying techniques that will recover the suns' heat from the road surfaces than mechanical regeneration from the vehicles. Another way to think of it, cars are designed to roll. To recover energy by modifying the surface of the road, you need to inhibit their rolling. This can't be achieved to any meaningful effect without substantial modifications to the surface properties (effectively you would want your road to turn into something like foam) but the road can't be that soft all the time if you want to 'regenerate' the kinetic energy of the vehicles braking only. At present the only practical compromise is to have a hard surface similar to the current road surface, generate only a fraction of the energy lost by braking and generate energy when the cars aren't in need of braking as well. Effectively you're not gaining anything at all. At the moment the practical openings for effective traffic energy regeneration are on the vehicle itself - from a system perspective roads infrastructure would have much more energy to save from devising a system to remove the need for cars to brake during their journeys in the first place. Last edited by mtma; 4th July 2012 at 8:58 PM.

5th July 2012, 7:55 AM	#6
Widman Member Join Date: Dec 2009 Posts: 624	TJANSTAAFL __________________ Widman's Quest for Home Network Nirvana is temporarily financially unviable Part I - NAS Main Rig: i7 920 - Gigabyte GA-EX58-UD3R - 6gb OCZ DDR3 - OCZ Vertex 2 240Gb +2xWD5000AAKS - MSI HD5870 + 2x U2410 over DVI - Xonar Essence STX+AD900 - Seasonic SS-650HT

5th July 2012, 5:13 PM	#7
LINUX Member Join Date: Sep 2001 Location: Dudley, Newcastle Posts: 3,027	From what I've read energy harvesting techniques aren't being developed as sources of large amounts of power. Typically they seem to be implemented in remote electronics to remove the need for batteries/solar panels/etc. For example someone at the Newcastle CSIRO (I think it was Chris Knight, maybe you've talked to them?) developed a system which generated electricity from trees swaying in the wind in order to power remote weather stations. Another system I read about used traffic induced vibrations on a bridge to power monitoring electronics (strain guages, wireless link, etc) so that somebody didn't need to climb the bridge periodically to change batteries. Further reading (which you may have already seen): http://www.csiro.au/en/Outcomes/Ener...sor-nodes.aspx __________________ www.vk2mev.net - Electronics & Amateur Radio blog

6th July 2012, 1:12 PM	#10
Bastard Child Member Join Date: Jan 2006 Location: Crooklyn 3012 Posts: 2,063	Set induction coils in the ground and rob passing vehicles of some velocity Or this http://livepaths.brinkster.net/livep...?contentid=888 __________________ I'm the reason we can't have nice things

4th July 2012, 8:25 PM	#2
orcone (Banned or Deleted) Join Date: Aug 2009 Posts: 335	Road-rage powered pedal system to charge the battery. I also have no idea what you're talking about.

5th July 2012, 5:46 PM	#8
bonox Member Join Date: Jul 2001 Location: Sydney Posts: 3,214	what's the strain of the crystal like? If it's down in the less than 1% bracket, then it's not really imposing a more significant impediment to movement of the vehicle than a roadway is already. Obviously, as you compress the crystal, you need to apply effort to climb onto the next one, but you already do this with asphalt/concrete/dirt/grass anyway. That being the case, you really do have a money for nothing scenario, since the vehicle passing over the surface isn't having to provide more energy that was being lost to the roadway/tyre deformation anyway. As crystal strain increases, this becomes less and less true to the point where it's like driving in sand. From my brief knowledge, piezo-electric crystals have very low strains anyway, so I can see how this might work in practice. Special large strain units are still only ~1-2% http://www.physics.montana.edu/eam/highstrain/ so it stands to reason more traditional units are smaller and if layed as thin membranes, your vehicle climb is practically insignificant compared to standard layered pavement http://www.scribd.com/doc/13274376/S...halt-Pavements

6th July 2012, 10:31 AM	#9
bigfellla Member Join Date: Oct 2011 Posts: 169	Yes it is Chris that I am speaking with. Interesting stuff. I am meeting up with him shortly.

6th July 2012, 6:20 PM	#13
mtma Member Join Date: Aug 2009 Posts: 2,601	Perhaps my elaboration has obscured my point. My current view of the problem is that you are attacking the (metaphorically) 2% side of the problem, when in fact you could be addressing the other 98% with substantially less effort and substantially greater results. I don't have all that much problem with the theory - for reasons of utility it's in fact quite effective for say the measurement equipment mentioned previously - it's just from a useful 'energy recovery' perspective it currently doesn't make sense to do it against other possibilities. It's one of those things that it's nice to keep your hand warm in research with but it's going to be decades before it's going to be meaningful, or it might even stay forever a niche product. Perhaps the good work they've been doing at CERN will reveal some magic much quicker that I might expect, but that's also true for every other element of energy generation, transfer and use.