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.