Dumb. An occasional train rushes through. From each passage, a tiny fraction of the wind energy might be recoverable. Untold millions of dollars per mile for what, a few kilowatt hours per month? And that\'s an extremely optimistic estimate.
The question is: is this more cost-effective than harnessing natural sources of wind? It would be hard to believe - but presumably they have done their sums.
Gadgeteer, I couldn\'t agree more. What a waste of resources, use the same turbines in a place that the wind always blows.
Also, I would imagine that you are causing wind resistance.
Long time reader/imaginer, first time poster... The point is not whether this product is cost efficient yet or not. The point should be how can they improve and go on from here.
@Abe: some subways run 24 hours a day 7 days a week, i dont know any other place on earth with as measurable a consistent wind as that. everything can be geared to that specific tunnel and the speeds they know they travel.
@Gadgeteer: i agree long distance trains would not be feasible. focus should be on subways... improvements always need to be made. But this is the first article on a new tech, why shoot it down before it is made better?
As much as I agree with Gadgeteer and Abe, there is a fundamental point that this article is missing: if you tap into this energy, you will increase the resistance that the train is experiencing.
It will only be a tiny increase, but then again you will only produce a tiny amount of energy. Basically, people: YOU CAN\'T GET SOMETHING FOR NOTHING!!
If you use the heat of your feet to charge your mobile phone, you\'ll be cooling your feet, if you use the energy of your steps to do so, you will require more energy to walk, if you extract the energy of the vibrations of rails, you will introduce an extra elasticity in the system, requiring more energy for the train running on them!
Ultimately, it all comes down to the second law of thermodynamics - as always.
This type of projects puts us Product Designers to shame.
On train tracks, it would produce one super tiny amount of electrical energy, and would only pay for itself long after it turned to dust.
On subway tracks, this would also generate a tiny amount of energy, except that it would also increase the drag on the subway train.
The value of this is zero.
Hmm so we assume the train is having drag or resistance because of the current track design - so if you designed these fans to move the air in a better way away from the train then in theory could you not improve or decrease the effect of the drag on the train, so thereby any increase in restance is actually balances out by reducing the original drag.
I am so tired of these sorts of schemes masquerading as being useful. This is merely a hugely inefficient way of turning fossil fuel into electricity. You might as well mount a wind turbine on top of the train.
I agree with most of the posters here. I think there are better ways to capture that energy.
It seems to me that something like the Windbelt would be cheaper to manufacture, easier to install and potentially give you more energy. If the Windbelt was installed so that it was attached to the rail, you could get vibtations form both the rail and the wind.
As the train approaches, the rail would be vibrating long before the wind effect, resulting in 2-3 times more energy generated.
It certainly seems to be that based on simple conservation of energy principles, the increased drag on the train would come close to equaling the energy produced by the generators. Come to think of it, it might be more cost effective to find a way to reduce the wind generated by improved aerodynamics of the train or the tracks themselves (make the tracks allow air to move more smoothing over them so that it does not drag on the train).
I love the idea of the fan on top of the train. Lets put lots of them up there. Then perhaps you could generate enough electricity to power the train(lol)
Lets not forget rain and snow(the wrong sort) gumming up the works. This is the idea of a madman.
Hey let\'s put in some magnets with coils round them, then the train will generate current as it passes over. Yes, I know: This would cause a resistance to the train\'s motion. How about setting up a load of microphones up along the track. The sound of the passing train would generate electricity. All wacky ideas!
Gavrillo is absolutely correct, in order to power these turbines, wherever they may be placed, more energy must come from the train, therefore gain is unity MINUS friction, heat loss etc. You are left with just an exchange, and more effort required from the train.
Benefit can only be gained from a naturally occurring source, unless the lost energy can be used for say, braking, change of direction, heating, etc. etc.
The wind the gadgets would be harnessing has already been set in motion: how would that increase drag on the train?
While i agree that the idea doesn\'t sound practical, there is the consideration that the things would allow for the outflow of air from building up under the train, which does happen. Harnessing lost energy is not a \"zero sum\" situation.
Coils under the track would put a direct drag under the train, as would mounting turbines on the train. the devices only harness what would be other wise wasted.
I know the microphone idea was in jest, but the fact is it would only be harnessing the sound that the train made anyhow: no drag on the train.
Here is a thought: use these devices, and the microphones, to generate canceling soundwaves the same way that noise canceling headphones do.
It seems that it would better to try to reduce the amount of wind generated. It\'s usually orders of magnitude easier and cheaper to prevent \"waste energy\" than to harvest it!
There is indeed an energy plus.
That comes because the drag is decreased by the turbines. The normal track bed is a fix barricade which builds up air pressure = drag. The turbines are not fix, they start rotating. This is like lowering the relative speed of train/ track bed. And that will lead to a decrease in air pressure = less drag.
BUT the amount of energy will be veeery little. There is more of a pressure change than wind beneath the train. And there is no way that this system will ever be cost effective.
Such a lot of devices, wiring, electronics, maintenance... and the energy will be lost on its way to a potential user anyway!
So, nice idea. But useless. Sorry.
uh gavrilo, you are talking about a closed system or circuit where you can calculate the energy in the system. That is a closed system.
With a train you have an infinite number of energy inputs, like... sun, wind, nutron and nutrino bombardment from the universe in general etc.etc.etc. so the second law of thermodynamics does not play here.
It more like in an airplane where you cannot fly and its impossible to fly because you are heavy and there is something called gravity... But there is another law that overcomes the law of gravity, it is called the law of Aerodynamics that as long as you are moving,... you can fly.
this would be perfect even if there was some drag involved involved, especially if there is drag involved since high speed trains are reported to need a certain drag coeficient to have high stability.
I agree with D.Advocate - you are all so boringly defeatist. does it take an old person like myself (and probably others who are just browsing and not registered) to see that this has brilliant potential? Maybe you lot would just like to go along witht the hyper expensive nuclear energy programme that\'s being foisted on this country.
yes we can all see some defects (mostly pointed out in the original article) but its a great idea and the energy is available there to be converted, if the right locations are chosen.
When we first had our solar panels installed, people said we\'d generate such a small amount it wouldn\'t be worth the initial outlay. Well, we aren\'t the equivalent of even a small power station but we are selling electricity back to the grid and hoping to save massively on rising fuel costs.
With modifications and a public with a bit of vision (!) I can see this scheme working at some time in the future. Good luck inventors, all our hopes are with you
\"The wind the gadgets would be harnessing has already been set in motion: how would that increase drag on the train?\"
Have you heard of back-pressure?
Could they not adapt them and put them on the trains or under the trains that way they would be working all the time and much less cost and could they also be fitted to all public transport that way when the buses etc return to base they could contribute if not run all electrical services a massive saving
Those who think the turbines would leach extra energy from the train are seriously wrong - the energy that powers the wind is already being lost by the train, and the turbines would scavenge only that energy which the train is already losing. The turbines would not create so-called "back pressure" - some people whine about laws of thermodynamics without any understanding of the actual science.
However, that said, the small amount of energy that would be created by each generation unit is not going to be worth the cost of the unit - even in a tunnel. Turbines and dynamos are very expensive to build, and would also require huge maintenance costs. A much better idea is to improve the train's aerodynamics, to reduce the energy lost to wind resistance in the first place. Also, subways normally have chimneys to allow air pressure ahead of the train to dissipate - otherwise every train would drive a slug of air ahead of it through the tunnel which would require massive additional energy (and blow the waiting commuters back into the street!) Improve those chimneys to remove air resistance in the tunnel even more efficiently, and get a much better return on your investment.
\"The turbines would not create so-called \"back pressure\" -from wayne247, and also \"the energy that powers the wind is already being lost by the train\" operative words \'BEING LOST\'.
Wonderful! In that case they will carry on turning forever, minus the braking effect of friction of course!
The air moved by the train is double sided you know, it is compressed between the train and the turbine blades, and in order to turn these, an equal and opposite force is set up against the initiator of the air movement, viz. the train. q.e.d.
Let\'s make it simple, forget the physical laws, and think of pumping up your bike tyres....of course it rquires no effort does it?
Or you can make the track more aero dynamic and save some energy instead of trying to recover inefficiency.
Hairbrain scheme. @GrannyVe:
Pity I had hoped old folk still remembered a decent education that included math. An expensive device between each sleeper. Le\'t throw some numbers at this and let\'s for sake of this discussion ignore that the energy this captures doesn\'t go at the cost of the energy taken to move the train in the first place (Which it does. Anyone with a basic knowledge of aerodynamics would know this)
Let\'s be super optimistic and assume one device produces 100 watts of power as the train passes.
The pressure wave would only occur at the beginning of the train. Let\'s say that pressure wave is reasonably long at 10 meters. When the train moves at 100km/h that means that wave has passed in 0.3 seconds.
Let\'s be super optimistic and assume there is no such thing as inertia. In reality of course there is just no way you get a stationary turbine rotating in 0.3 seconds. That would require a dramatic acceleration only possible on tiny paper windmills.
With sleepers approx spaced at 0.8 meters you would have 13 devices within the pressure wave at a time. Thus generating 13 x 100 = 1300 watts.
Mind you, you only get that 1300 watts for as long as there are these devices to pass over. So let\'s try to generate this power for 1 hour. This means a piece of track the length of 100km needs to be equipped with these generators. That is only one hundred twenty five thousand generators (125000). I am guessing these things don\'t come cheap. Say $500 a pop? So there is an investment of 62 million dollars to generate 1.3 kwh for every train that passes over this track. With the current price this 62 million dollar invention generated $0.10 worth of energy.
Even with a train passing every minute you would generate at best $6 worth of electrical power on this 100km piece of track.
Of course we will just ignore the maintenance nightmare to keep these 125000 generators clean and working.
Just for kicks, lets see how many km of track and dollars you need to generate 1 gigawatt of power which is what one single nuclear powerplant produces. 100 km of track generates 78 kw of power provided a train passes every minute. It would take 1282051 km of track with a train passing every minute to generate 1 gigawatt. This track wraps around earth 32 times and costs $795 billion dollars. But that is just the track. You need to have 76920 trains running continuously to generate this power. I guess a nuclear power plant sounds pretty environmentally friendly now doesn\'t it?
To even suggest that this could work and we need to use vision to make this happen is beyond idiotic. A post that makes a mockery of maths, let alone science. Do people still think these days or is wishful thinking all it takes to make things true?
Paul van Dinther
And what about an aerodynamic maglev subway? conect those with some capacitors under the monorails rails and store the energy to help the next train that passes... just sayin xD
@Paul Van Dinther
Why would someone spend all this time modelling and rendering something so idiotic as this without thinking the practicalities through AT ALL!?
You might be right except for the fact that the impervious spaces between sleepers create more \"back pressure\" than the turbine blades would. they are not only immovable, their mass is effectively the same as the train.
Moveable turbine blades won\'t mass anywhere near what the train does, and much of the air will flow past anyhow, which will spin the blades, providing rotational energy to be harnessed for power.
Any \"back pressure\" will be negligible, and certainly less than conventional track setups.
Just thinking... if this is a good idea attach it to the train instead of the track, then you only need one unit, and the user of the electric is the train so no transmission problems either.
Not only does it make more sense from a practical point, it highlights how stupid the idea is in general :)
@ Darren Johnson.
We are not talking about space between sleepers, or of energy loss caused in any other way. Mass of a space the same as a train?
You do agree however that there is some back pressure created by the turbine blades.
Air movement generated by the movement of the train turns, [applies a force], to the turbine blades.
The force required to turn the turbine has a value, say X.
There is an equal and opposite force X applied to the generator.
The only energy generator in this equation is the movement of the train.
If you disagree, maybe you could tell us from where that X may have come?
Okay this is a great idea however wouldn\'t it be a better Idea to attach these to the out side of a train and capture the electricity via a system similar to that used to move a bumper car. It would be less costly, produce more electricity, and it would be esier to take care of them. Just saying.
What are the 'Balancing device' and "power transmission device" Used here?
pl tell me detail about T-box concept & which type of blades are used in the turbine in the T-box