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Author Topic: Useing roads like power plants.  (Read 2342 times)

Offline ScientificSorcerer

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Useing roads like power plants.
« on: 12/03/2014 04:23:46 »
Me and my dad got into a conversation about using cars to produce energy for road lights, we came up with 2 ideas.

My idea was to put piezoelectric ceramic plates under the road and when cars run over the plates it presses on the plates in-order to produce electricity. most piezoelectric stuff is remarkably cheap and could possibly utilize the weight of cars, trucks and 18 wheelers to to produce electricity for various street lights or even more.

His idea was to put magnets under cars and coils under down hill roads, when the cars move down hill the magnets induce currents in the coils in-order to produce power, this would of coarse slow down the car but that wouldn't matter because the car would be traveling down hill and the energy would be drawn from the force of gravity.  I told him that it might attract random trash from the road like nails which might help roads be safer, but at the same time it could be dangerous if you picked up a large piece of trash.

Both of these Ideas seem logical to me but we want to get some scientific feed back from you guy's to see what you think.


 

Offline DanielB

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Re: Useing roads like power plants.
« Reply #1 on: 13/03/2014 19:57:20 »
You know it would be funny,, if they would actually put the copper coils in the vehicles tires,, and with load stone inside the asphalt,, would produce eletro magetic generation.  The only thing I would have to consider in magnetic rides.. 

1.  What would the current magnetifield do to the cars current electronic brain.
2.  The faster you go, the more energy you make,, (pace makers). 

SS,  this is something,, that will be fun to work with,, let me come up with a thought or three.

Now I do like this thread.  ty for the thought provoking manner. 

DanielB
 

Offline RD

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Re: Useing roads like power plants.
« Reply #2 on: 13/03/2014 22:02:42 »
My idea was to put piezoelectric ceramic plates under the road and when cars run over the plates it presses on the plates in-order to produce electricity.

Apparently not economically feasible ... http://large.stanford.edu/courses/2012/ph240/garland1/ [400kW per km seemed OTT to me too]


... put the copper coils in the vehicles tires,, and with load stone inside the asphalt,, would produce eletro magetic generation.

If the road was magnetic it would act as a brake ... https://en.wikipedia.org/wiki/Eddy_current_brake#Circular_eddy_current_brake
 any current/heat generated would be at the expense of kinetic energy,  [no such thing as a free lunch]
« Last Edit: 13/03/2014 22:14:27 by RD »
 

Offline alan hess

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Re: Useing roads like power plants.
« Reply #3 on: 13/03/2014 22:57:48 »
The wrinkle I see is keeping the roads properly paved and potholes, they can handle that. Now were only doing shovel in some blacktop
 

Offline ScientificSorcerer

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Re: Useing roads like power plants.
« Reply #4 on: 15/03/2014 23:32:59 »
RD

you said the road would act like a break because of eddy currents, we thought of that. That's why the magnets/coils would only be on down hill roads. the force of gravity is were the energy comes from, I hope I cleared up that problem.

as for the pizo-plates under the road, I would have been happy to see that the roads would produce just one kilowatt let alone 20 kilowatts for 1 kilometer of road. That's all energy that would have otherwise been wasted. The roads could generate just enough power for street lamps and stop lights (billboards and what not) In my mind your article is proof of concept. It would work.

alan hess provides an interesting point that I hadn't thought of, "what if it breaks" how would you repair it? it's hard enough just repairing pot holes but if some coil stops working under the road then how would you fix it? you would have to dig up the road with a whole team of road workers and it would cost a fortune.
« Last Edit: 15/03/2014 23:45:12 by ScientificSorcerer »
 

Offline RD

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Re: Useing roads like power plants.
« Reply #5 on: 16/03/2014 01:12:25 »
RD

you said the road would act like a break because of eddy currents, we thought of that. That's why the magnets/coils would only be on down hill roads. the force of gravity is were the energy comes from, I hope I cleared up that problem

The fuel in the vehicle is where that energy comes from : the vehicle wouldn't be at the top of a hill without it.  Having regenerative braking in the car seems a more feasible idea ... https://en.wikipedia.org/wiki/Regenerative_brake
  [ apparently there are regenerative shock absorbers too ]

I would have been happy to see that the roads would produce just one kilowatt let alone 20 kilowatts for 1 kilometer of road. That's all energy that would have otherwise been wasted. The roads could generate just enough power for street lamps and stop lights (billboards and what not) In my mind your article is proof of concept. It would work.

Quote from: bbc.co.uk
The lamps used in streetlights vary in both size and consumption, but are typically between 35 and 400 watts,
http://news.bbc.co.uk/1/hi/magazine/7764911.stm

Lets split the difference and say a street-lamp uses 200 Watts,
 at "one kilowatt ... for 1 kilometer of road", that's only one lamp every 200 meters.
In reality the maximum spacing is about 50 meters, (typically 30).

There's the economic and environmental cost of the batteries to consider, [ lead?, Lithium ? ]
You'd need to do a cradle-to-grave analysis to see if it made sense economically and environmentally.
« Last Edit: 16/03/2014 01:25:33 by RD »
 

Offline ScientificSorcerer

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Re: Useing roads like power plants.
« Reply #6 on: 16/03/2014 03:00:47 »
True, but I would think the energy would just go into the power-lines which are usually right next to the road, and just add on to it's power, but I don't know what you would need for that to work, you would need to convert the power into ac then transform it to the proper line voltage and frequency. This approach wouldn't need batteries but the energy wouldn't go directly into the street lights but extra power is generated so that's still a plus.

 But the biggest cost would be in a lot of big ole pizo plates, no telling how expensive those would be but I estimate the price would be in the $100,000 range for a good sized stretch of road.  I bet the most cost effective place to put these plates is were the most cars are, like a busy high way. in a place like that you could get the most bang for your buck. you could even use the plates like car sensors to turn on light only when they are needed, not when there is nobody to see the light the lamps make.  so not only would the plates produce power but on top of that it would help roads be more energy efficient (just another plus).

usually high way work ranges in of million dollars, so an extra 100 grand for all of these features seems like a good deal, but IDK about the cradle to grave math.  It seems like a good deal to me, if I was a highway contractor I might look into it, but this sort of thing requires tests to see if it's worth it or not.
« Last Edit: 16/03/2014 03:08:07 by ScientificSorcerer »
 

Offline RD

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Re: Useing roads like power plants.
« Reply #7 on: 16/03/2014 04:25:37 »
The usually sums don't add-up for parasitical power generation ...

Quote from: .cnet.com
The MIT News reports that two MIT graduate students in architecture have proposed to extract energy from the motion of humans through public spaces such as train stations:

Quote
    A responsive sub-flooring system made up of blocks that depress slightly under the force of human steps would be installed beneath the station's main lobby. The slippage of the blocks against one another as people walked would generate power through the principle of the dynamo, a device that converts the energy of motion into that of an electric current.

But if there's enough motion to provide harvestable energy, there's enough motion for the humans to notice. Ever walked along a pedestrian suspension bridge that bounced under your feet? It takes more energy to walk on such a surface than it does on a rigid surface.

Where does that energy come from? From you, of course. It's like carrying a parasite that takes a little bit of your energy. In fact, this approach is also called parasitic power generation. By keeping the parasite fed, you get a little more tired and you eat a little more food. In effect, you become a highly inefficient motor that runs on food.

Food calories are inefficient to produce. A wheat field is a giant biochemical solar panel that turns a small part of the sun's energy into chemical compounds that you can eat.

And then those compounds have to be kept cool and transported large distances, then cooked and eaten. By comparison, traditional electric power generation is hugely more efficient.

So when you see celebrity Ed Begley Jr. using a stationary bicycle to turn a generator to power his toaster, remember that this is a crime against the environment--not environmentalism.

The same goes for parasitic energy generation--it creates exceptionally expensive energy.
http://news.cnet.com/8301-13512_3-9779334-23.html
 

Offline alancalverd

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Re: Useing roads like power plants.
« Reply #8 on: 16/03/2014 07:38:09 »
Any energy you extract from a vehicle travelling at constant speed must come from the vehicle's fuel. In most countries, vehicle fuel carries more tax than fuel for power stations (which is why electric cars are cheaper to run) and is also more expensive to produce, so the suggestion merely increases the cost of electricity and, by adding cost to road transport, the cost of everything else.

Using electromagnetic regenerative braking is not a new idea. It's been done on trains and buses for many years and is now standard practice on electric cars. But it is under the control of the driver. If you fix a passive regen system in the road surface you have created two problems: (a) "downhill" for you is "uphill" for me, and I really don't want to apply the brakes when going uphill  (b) you are preventing fast downhill traffic from overtaking safely: the object of safe overtaking is to spend as little time as possible on the wrong side of the road. Even if you only put your brake system on one side of the road, it inhibits acceleration in that lane and thus makes the overtaking manoeuver more dangerous. 
 

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Re: Useing roads like power plants.
« Reply #8 on: 16/03/2014 07:38:09 »

 

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