Supermarket generates piezoelectric power in parking lot
By Joseph L. Flatley 
posted Jun 15th 2009 10:46AM
posted Jun 15th 2009 10:46AM
Remember that piezoelectric road prototype we saw late last year? Looks like someone (besides us) thought it was a good idea. According to The Daily Mail, a Sainsbury's supermarket in Gloucester, UK (you've never been there), has installed kinetic plates in the parking lot that use the weight of shopper's cars to pump a series of hydraulic pipes, which in turn drive a generator. The system is said to generate up to 30kw of energy an hour -- or enough to power the store's checkouts. And if that weren't enough, the store is also harvesting rainwater and heating it (during the summer, at least) with solar panels. The next in this store's "eco-friendly evolution?" Might we suggest Soylent in the deli? We hear the "green" stuff is particularly good.
[Via Green Launches, Thanks Deepa]
[Via Green Launches, Thanks Deepa]
Hmm..wouldnt this in effect be gasoline powered electrics. The cars will use extra fuel driving up onto these plates, although minimal per car - but the net effect would be electricity generated by gasoline (at the expense of the car owners).
Ya so is you driving your car down the road. It creates friction which is what causes the loss of energy and fuel mileage. C'mon people quit bitching. People will find anything to bitch about these days and people have nothing else better to do but bitch about alternative energy sources lately.
I have been there. It's very clean
You obviously have NOT been there, because if you had, you'd know that Gloucester is Cheltenham's poorer, scummier, dirtier, druggy cousin.
Actually, the Gloucester store in Barnwood (my local Sainsbury's), Gloucester is a very clean and modern store, and the Sainsbury's on Tewksbury road in Cheltenham is old and dirty looking with an uncomfortably low roof. I think there's a new Sainsbury's in Cheltenham but haven't been there so can't comment.
Bugger that, the whole South is a shithole.
T' NORTH SHALL RISE AGAIN, PET.
I've been to Gloucester but I've never been to that Sainsbury's.
So basically they're stealing our gas to power the store...
@ Mike
I appreciate your attempt at wit... but saying what you did is like me telling you that you're stealing my oxygen to combust your petrol.
Dang, I had an idea like this a few years ago... but you know how that goes. Having a idea is easy, it's making it a reality that counts.
The kilowatt is not a measure of energy. It is a measure of power. They could say it generates 30 kWh of energy per hour, or say it generates 30 kW of power. Also the technology they describe is not "piezoelectric" at all.
Wouldn't this ultimately rob more energy from your car than it would generate for the store?
Unless the plates are on the descending side of a garage ramp, where gravity is doing a lot of the work.
My thoughts exactly. So basically they aren't just taking your money, but some of your gas too.
Well yes, but that's not necessarily a bad thing. If, for example, the plates are positioned in an area where the car is slowing down then the energy it takes from the car is energy that would be otherwise wasted anyway. Only if the car has to accelerate over the plates, would the plates be 'stealing' energy from the car.
How would it do that? It's nothing more than really short speed bumps. It would be like driving on your yard, your tires would sink a bit. Now if they were rollers with little generators on them, yea, I could see that robbing power from your car.
I think they should install big ass magnets on the bottom of all those semi trailers. Put coils in the highways. It would also pick up bits of metal junk on the streets, win win!
@barry99705
There is a little thing called conservation of energy. If the car sinks even slightly then it will need to use more energy to get back up again and this energy is likely to be more than is generated by the store system. If however it is (as some people mentioned above) at a point where either the cars are slowing down or on a down ramp then it is essentially clean energy harvesting. Adding magnets to all trucks may well help clean up the disgarded metal on the roads but unfortunaltey would have a dramatic effect on the fuel consumption.
How much gas are we wasting here exactly? The contraption looks relatively simple and efficient, imo.
Unless the tracts are very resistive when you drive over them, I don't see how this can necessarily rob of us our money. I see lots of whining though.
That also was my first thought.
If it generates energy by pressing down something, then the car has to go up again after it, and thereby consuming more fuel.
For the single car (and therefore the single customer) it wont matter, since the amounts of fuel are probably in the mililiter range, but i doubt the overall efiency of the whole thing!
If its generating 30kW, those get entirely generated by the burning of petrol, but probably way less effiecient than directly at a power plant. So i would guess that this could be less environmentally friendly than to simply get the energy out of a powerplant.
Of course if the placed it in an area where you would waste energy anyways (under a ramp oder something similar) then it might be different.
Actually, there is always some flex in road surfaces as vehicles move over them. Asphalt pavements are often refered to within the industry as flexible pavements for this very reason. If (that's that's a big IF), this system would only be harnessing the energy from the existing flex, then it would be capitalizing on otherwise lost energy.
I'd expect the increased gas usage would be similar to driving on under-inflated tires.
It's just in the parking lot, if you don't like spending 0.001% extra petrol in the half minute you're driving in there, don't go there.
We're not talking "humps" in the ground like speedbumps, the plates are under the road surface and not visible to the user. Think of it like this: if you bury a pipe under some dirt, flatten the dirt, and walk on it, are you losing much energy by traveling over it? Not really. The plates don't protrude past the road-going surface, as far as I can tell (from their picture and past articles on it). IMO doesn't even make sense to have them above road surface.
If I understand the diagram and piezoelectricity, then this is actually not wasting gasoline. The ground doesn't "dip" so much because the crystals don't have to be compressed a lot to generate a voltage. We're talking movement on the order of millimeters in movement, at most. A minute amount of deformation (due to applied force) can result in a usable amount of voltage, at least when you have enough of the crystals being compressed simultaneously. One crystal by itself is nothing, but line up a few thousand of them and you're getting some decent output. Your car doesn't have to overcome a large dip in the ground nor a (speed)bump.
That's more than my 2 cents, but there you go :)
Rogue_Genius:
I agree. These pseudo-scientists keep talking about how they're stealing energy from your car and blah blah.
That energy is ALREADY being wasted. It goes to the road, depresses it, makes it vibrate, and eventually destroys it. This is just using that.
This is the stupidest thing I have ever heard of. The energy comes from the cars, and is only as green as the average car. It is not free energy unless somehow you managed to set it up so that the pads are exactly at a place where all the cars would be breaking anyway.
It would only work if you used these instead of speed bumps. Otherwise it's just using the gasoline as others said.
Well, it's free energy as far as Sainsbury's are concerned...
Just like lunches, there is no such thing as "free energy".
Unless you're counting this perpetual motion machine I have in my back pocket.
Speed bumps.
They hang out in parking lots, you know.
Once people drive electric cars, it becomes a straight transfer of electric energy from your home garage charger to the store, minus efficiency losses in charging/discharging the car battery and converting mechanical energy to electrical at the store. It's obvious that the systemically more efficient plan is to just run the store from the grid - or put solar panels on the roof.
So now the supermarkets want to steal energy from our cars? There is no free energy, the car slows down over those bumps, requiring more energy to push it along.
It's sort of like the tax system.. Take 25% of my check, then take another 10% when I shop, tax me for phone service, my property.. we aren't a democracy, we're communism and we just don't know it, and we don't even get free health care.
Communism is democracy.
"Communism is democracy."
Must be why so many people tried to escape from east germany. They didn't like democracy.
Actually, he's right: communist ideology is extremist democracy.
In practice, communist regimes tend to be more fascist than communist. You can't have a communist revolution brought on by a few - you need most of society rising up at the same time.
That has nothing to do with the topic though.
Oh, and the UK does have 'free' health care. Whether or not we have health insurance is something the British haven't needed to worry about since the second world war.
Communism is an economic system, while democracy is a political one. They are neither the same nor mutually exclusive.
And smp hits the nail on the head.
I have been there actually - used to live a few miles from it.
I've always thought that gathering up lots of small amounts of energy from something as large, heavy and inefficient as a motor car is quite bizarre. Yes, such a device may generate a healthy amount of energy, over time, but why not concentrate on making the inefficient heap of metal even half a percent more efficient, which given all the cars travelling through the car park would probably save equal or more amounts of energy overall.
How about extracting the heat the cars send off after parking? I think that would produce more energy then it's weight flipping a switch wouldn't you say?
"The system is said to generate up to 30kw of green energy an hour"
How is using the engine in my car to generate electicity more green then using a power plant?
Exactly. It's not.
It might be if you're still burning coal.
Something similar was on Discovery Channel (i think).
Using the same concept as above but for sidewalks in major urban areas to power street lights or something. But I don't this this version used hydraulics.
It depends on WHERE exactly they installed the plates.... If they install it in the areas where cars have to slow down (for example just before a sharp corner or a steep down ramp) it DOES not require more energy from the cars engine, it will then use part of the energy normally wasted as heat in the cars brake disks.
Unless of course you are driving a hybrid with regenerative braking. Then they are stealing the energy you would have put back in your batteries.
Can you clarify how much energy it is producing? "30kW per hour" is meaningless. Thats a rate of change of power.
Assuming constant peak power output for one hour, it would produce 108 megajoules of energy.
~the more you know~
No, the numbers provided still make no sense. It's one of those things where it's useless to attempt any literal interpretation of what's said because the data has obviously been taken out of context and misused.
"Generating 30kw of energy in an hour" is like saying "generating 70mph of speed in an hour." Notice the redundancy there? 'Watt' is a *rate* just like 'mph', not a quantity.
So we can only guess. Does it actually generate 30kW? For checkout registers?! That's a HELL of a lot of energy. Did the original source state 30kwh (kilowatt-hours) over a period of time, like a week? That'd be 178 Watts of power, which is a lot more reasonable but probably still not true.
They are doing it because they can. Not because it makes sense from an overall efficiency standpoint, not because the effort and expense spent on this system wouldn't have had greater yields applied elsewhere, simply because they want to and they can.
Not a bad or evil thing, but not much to get excited about, either. I wonder if they'll bother to maintain it in working order, or just quietly switch it off when it costs 10x as much to maintain this system as it does to purchase equivalent power from the grid.
Next we'll have hydraulic cylinders in the stools at Dunkin' Donuts.
I smell money in this idea.... considering a 300lb man sitting on a chair that pushes a down the chair by a few inches can generate some electricity... makes the person have to stand up from a lower level requiring making 300lbs man use more energy which makes him lose weight after eating donuts... win win situation
Everytime you see something like this, you have to think, "What's the payoff?"
The article fails to mention some important details:
1) How much did it cost to put in the system (including maintenance costs for the projected life of the equipment)?
2) How long will it take to payoff?
3) Does the time to payoff exceed the life of the equipment (as is typically the case with current generation solar panels, especially without tax subsidation)?
4) What is the net environmental impact, considering energy / carbon costs of development, production, shipping, maintenance, et cetera?
Of course, it's certainly possible it's just a marketting angle to pull in a bunch of "green" shoppers.
Four very good points that it seems most people forget when schemes like this are floated.
I guess you could argue even if this system does come at a net energy loss, it does work to focus minds on the issue. In this specific case though this is quite obviously a gimmick to lure in the 'green conscious' shoppers, as Carlton states.
Like most 'green' projects, you nailed it with the last part. It's more for appearances and marketing than it is an effective idea that solves problems in the best manner possible.
Why are cash registers using 30 kw of power?
Why don't they just put in solar tubes to reduce the amount of lights they need to have on? Stores are mostly open during the sunny part of the day.
They could also put 30kw of solar panels over the parking lot, which would generate power regardless of how much traffic there is. It might also cool down the cars if they put them over parking spaces in the southwest, saving the customers air conditioning a little.
They did. Reading is power.
Depending on the design, this pull extremely little energy from your car. If the store's savings outweigh the customer's energy loss, the savings can be passed on by lower grocery bills.
Could pull*
Go go gadget editing!
How would the savings out weight the customer energy loss? The law of conservation of energy states that the total amount of energy in an isolated system remains constant. A consequence of this law is that energy cannot be created nor destroyed. The only thing that can happen with energy in an isolated system is that it can change form, for instance kinetic energy can become thermal energy. Because energy is associated with mass in the Einstein's theory of relativity, the conservation of energy also implies the conservation of mass in isolated systems (that is, the mass of a system cannot change, so long as energy is not permitted to enter or leave the system).
I think you guys are missing the point of this system. As I see it: 1) The piezoelectric energy comes from small crystals (probably fairly thin) that will not create any 'bumps' in the road, therefore, there would be no 'more' energy used by the car to drive over it as it would to drive over the normal road. All the crystals need is pressure to squeeze them to generate electricity. The pressure will be coming from the weight of the car, and doesn't need to be constant. The motion of rolling over it will do the trick. 2) These cars are going to be driving anyways, why not harness the power they can create? Until people stop using their gas powered vehicles, the potential energy they are capable of producing is being wasted.
The only problem with that logic is this system isn't actually a piezoelectric system. The Engadget writer is just pulling the word peizoelectric out of his ass. The article and the diagram don't mention piezoelectric crystals anywhere. This system works with movable plates and generators.
Been to a heck of a lot more exotic places than that. By exotic, I mean danker, scummier, and more dangerous.
Sure, I hear Baghdad and Kabul are nice this time of year.
"The system is said to generate up to 30kw of green energy an hour "
That makes no sense at all. Please get your terms right. kilowatts are a measure of POWER and not ENERGY. Yes, there is a HUGE difference. Are you saying it generates a continuous 30kw? if so then the addition of "an hour" doesn't really make any sense because it would generate 30kw in any period of time. If you're saying it generates 30 kilowatt-hours then please give a time frame for this (you mean a day? an hour? A year?)
Or are you saying that 30kw is the nameplate capacity for power output? In that case, giving some indication of the capacity factor would help. In either case saying "30kw of green energy" really makes my skin crawl, because it's completely wrong. You can't interchange power and energy. Unless, of course, you stated more clearly that 30kw was the output continuously - in the case the time variable would be implied to be an arbitrary amount of time multiplied by the power to give energy. (30kw of power = 30kwh of energy per hour)
Thank you! So annoying when people haphazardly interchange energy with power! Unfortunately, it seems that the source of the error is in the original source article - even worse!
Everyone seems to be insinuating that these are physically causing bumps in the road (either that the plates are above the road itself ala speed bump, or causing a bulge underneath), but I don't see evidence of that. All the article provides is an illustration (seriously, nobody could get a photograph of the area for what is essentially a free-press article, but they could get a full drawing?). So if the road surface is flat just as an ordinary road, then is the car using more energy or not?
Side note: The authors of the original article are not exactly physicists. I'm pretty sure that F1 cars don't create kinetic energy when they brake.
Yes, it could be flat but your tires might sink in, not humps that you drive over.
Also, F1 cars are allowed to use a regenerative braking system called KERS (Kenetic Energy Recovery System).
I just wonder if the road responds differently with these plates underneath it than it does with just earth underneath it. Surely as you drive across a normal road, some energy must be being transferred to the road and subsequently to the dirt, so perhaps these plates are just intercepting the energy that would be dissipated into the ground.
I'm aware of what KERS is. However I think you'll find that no vehicle should be CREATING kinetic energy while braking is not doing what it should be doing. That or McLaren has beaten the Law of Conservation of Energy.
I love Sainsbury's.
Put this under the feet of the fat shoppers so they get more exercise, not under the wheels of our cars so they burn more gas. Ridiculous.
Sounds like a good idea to me. Also that is my favorite model Mercedes S-Class in the illustration
Looks like an L-reg to me.
I don't know. Note the angle of the tail lamps and lines of the trunk and doors as compared to the following link:
http://photos.ebizautos.com/used-1999-mercedes~benz-s~class-s500-5428-3475300-2-640.jpg
I agree with some of the posters that this will simply take energy/fuel from the vehicle unless the system is placed in a location where the vehicle would normally stop or slow. What the stores should do is put small generators in the doors entering the establishment and not use automatic door openers. This way when people entering and push the door, it activates a generator and creates a small amount of electricity. Now people are creating the energy AND maybe reduce the weight of the population. There - two problems solved in one.
Seems very inefficient.
The internal combustion engine has a poor energy efficiency rating from the start... compound that by the inefficiency of the generators and you have a poor system from an environmental standpoint.
It would be much more efficient to use electricity from a coal/wind/nuclear power plant and let the car use less fuel.
what i dont understand is, according to the diagram...why is braking necessary/involved? and why isnt there a picture of this thing in real life anywhere? link plz
http://www.engadget.com/2008/12/13/prototype-piezoelectric-road-could-generate-power-by-simply-sitt/
read that plz...the power is generated by squishing of the piezo crystals or soemthing along those lines...no braking involved...?
"would have a dramatic effect on the fuel consumption."
You're talking about two subjects that vary immensely. We're talking about simple wannabe speed bumps that take a bit of our car's energy. I do agree that there is a loss of energy in the equation. Perhaps we should think how much gas will be wasted by simply avoiding this technology altogether -- by swerving around the parking lot or speeding away from the entrances to avoid the slowdown?
Where did my comments go? -___-
The system is using the potential energy in the weight of the vehicle, the forward motion shouldn't be affected anymore than hitting potholes or speed bumps. This means that you shouldn’t be “dramatically effecting fuel consumption.” This energy is normally absorbed by the suspension of your vehicle and the structure the car is riding on, which doesn't use any gas to work. Instead of the concrete absorbing this energy and doing nothing with it, this system turns it into something useful. Why is it so hard to understand the benefits?
Did no one else pick up on the Soylent comment.
"It's made of PEEOOPPPLLLEEEE!'
People?
Anyone I know?
Never been there? I was born there and just about to move back there after buying a house (the economic crisis is good for some things, at least, like making houseprices affordable again).
As to which store it is, I'm assuming it's the new one being built on the western bypass; unfortunately, google map's aerial imagery is a bit out of date, doesn't even show the new bridge over the canal:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Gloucester,+UK&sll=37.370157,-95.712891&sspn=53.789408,78.75&ie=UTF8&split=0&ll=51.858557,-2.258763&spn=0.005195,0.009613&t=h&z=17
i've always wondered why somebody doesn't create a television remote powered by piezoelectricity
Then, there should be generators on the generators, to convert excess heat to electricity. Then tons of wind generators in the parking garage to utilize car movements... Then extra generators on those... Then just put generators all over the place, so everything looks like Romanesco broccoli.
Free excess energy for everyone!!!!!!!
Kinetic plates pumping hydraulics is not piezoelectric.
This is a terrible idea. The energy needs to come from somewhere. That somewhere is the car, it requires more effort for the car to drive over and uneven or deformable surface. This generator essentially steals energy from your car and burns more fuel.
The headline mentions piezoelectrics, but the system in question is hydroelectric. Not quite the same thing, guys!
A piezo system would be much simpler, but I'm not sure how well the millivolts supplied by small-scale piezo transducers would scale to larger applications. Sure would be an interesting R&D experiment, though!
Well 30kW per hour is essentially 30 kWh written out in a more accessible form for the typical reader. If you go take a look at your electric utility bill, you'll notice that it's in kWh, which is a measurement of energy consumed - and is a *very* useful and meaningful measurement.
If you read the original article, 30 kW is the device's potential maximum output over an hour - dependent on the number of autos driving over the generators. They state that it is more than enough energy to power their registers. I'd wager they'd generate 2-3 kWh of power during typical business hours and traffic flows.
wrong. kW per hour is NOT equal to kWh.
now... they should use this electricity to charge electric cars from customers (.. for free) while they are shopping.....
"a Sainsbury's supermarket in Gloucester, UK (you've never been there)"
Oh really? It's where I do my weekly shopping :) (seriously!)
This idea on a flat surface = fail... I want gravity helping me.... The way to implement this idea it to have the store under ground where shoppers have to drive down a spiraling parking structure or something similar, hitting hundreds of these "bumps." This way = no extra gas generated from accellerating into the bumps. If you take this idea into a mass scale for all sloping areas, you could see lots more power generated with commute traffic and other roadways, not just a small supermarket lot.
Good way to show off the tech though!
So these guys never learned physics, right? Do they know where the energy comes from? From the engines of the cars that drive over those gadgets. 80% of that energy goes into space, of course. The store gets 20 cents from each dollar spent by the customers; the rest, 80% goes to... where? to those who sell gas? Oh, yes, and to the government heavily taxing gas.
Good job!
This could be used for underground garage parking.. people are going downhill and braking anyway; this would harness some of that downward momentum w/ less consequence. The exit ramp going up would not have this mechanism for environmental reasons.
I drive a Prius, so it WOULD be stealing energy from my car, even in a braking run (that energy would be used to recharge my battery instead).
If that energy is used to recharge your battery, then how come your breaks are getting hot?
Three things.
1) "The system is said to generate up to 30kw of energy an hour" - for that phrase alone, the author deserves to fail high school Physics class. Energy is not measured in kW. And there's supposed to be a capital "W".
2) Those of you who think that that "cars are going to be driving anyways, why not harness the power they can create" need to go back to school and learn the law of conservation of energy all over again. The only way to make this kind of system without robbing the customers is to place the platform at the exact spot where the cars are breaking. It doesn't seem to be doable.
3) To khanselman: "Until people stop using their gas powered vehicles, the potential energy they are capable of producing is being wasted". It's kinetic energy, not potential energy, there's a difference. And it will be wasted in any kind of moving vehicle. Electric cars included.
Overall, this case demonstrates once again that all that green movement is based on the people's ignorance.
No, no, no, no, no! This system derives its energy by taping into GRAVITY! The MASS of the car is sucking GRAVITY out of the EARTH and into CASH REGISTERS! Soon the EARTH will spin out of control and we will all plummet helplessly into the SUN!
Aaaaaaaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhh!
The 30 kW number is clearly wrong. An average American suburban house uses something like 3.5 kW to power all of its TVs, computers, appliances, etc., so the notion that a grocer needs 30 kW to power cash registers seems a bit off. Also, it seems unlikely that the energy from cars sinking down an inch or so could generate that kind of power - enough to power 500 lightbulbs.