New Jersey Turnpike As a Power Source? 264
New Jersites writes "New Jersey, home of the eponymous Jersey barrier, is considering wind turbines powered by the breeze generated from traffic on the Jersey Turnpike. The wind turbines won't be built on the side of the highway. They will be built inside — what else? — the Jersey barriers. By replacing sections of solid concrete with Darius turbines, they might be able to harvest enough energy to power a light-rail line."
Drag? (Score:5, Insightful)
I'm not a physicist, but won't the turbines cause a drag effect on the cars, resulting in the cars burning more fuel? Is so, aren't they just moving the problem from one place to another? There's no such thing as free energy, right?
Truly curious - I'd love an explanation if someone knows why this isn't the case.
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Re:Drag? (Score:5, Funny)
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Ghostbusters II: New Jersey Edition?
Re:Drag? (Score:5, Funny)
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>another? There's no such thing as free energy, right?
No it wouldn't cause drag on the cars
the cars are already pushing a wall of air, ATM that wall of air just dissipates after a while, the barrier would take that wall of air and convert it to some power
So in fact, its actually making the cars more efficient, as the wasted e
Re:Drag? (Score:5, Informative)
Re:Drag? (Score:5, Interesting)
I know it's not exactly high school stuff but if you think of it as simple 2D water flow it still is not difficult - the ripples from an obstruction only travel a finite distance upstream.
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Big Dig problem solved (Score:4, Funny)
Re:Drag? (Score:4, Insightful)
It's a really stupid idea.
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That would be true if there were only one car (or boat). If there is a flow of cars, those cars are going to consume less fuel if there is less drag due to an airflow.
Exactly how that flow behaves at the edge of a freeway is fairly important for the efficiency gains: a smooth wall may actually have a beneficial effect, while turbines would do exactly the opposite.
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Reason:
Put a clause in the traffic laws / license application that states that fact.
Layne
Re:Drag? (Score:5, Interesting)
Re:Drag? (Score:5, Informative)
The air moved around by the cars is being absorbed and dissipated anyway by the objects surrounding the road. All the turbines will do is instead of the airflow from the cars going to swish the surrounding grass, trees and bushes - it'll spin a turbine. The energy is already being absorbed by the surrounds of the road.
It's like putting a turbine over a kettle - you won't cause the kettle to use more energy to boil the water by allowing the steam coming from it to pass through a turbine - you'll just extract some of the energy that otherwise would have been used up by the environment of the kettle.
If it's designed correctly, it won't increase drag.
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The problem is that they are talking about putting the turbines in the median strip - the Jersey barrier. This currently divides the road into two airstreams. Sure, there is some friction at the barrier that will slow the airflow, but any energy that you suck out of the airflow has to come from the traffic. What you are saying is true only if they suck only as much out as they were losing to friction anyway, which I find unlikely.
Re:Drag? (Score:5, Insightful)
You've got it right. The turbines would take energy from the air being pushed around by the cars, leading to the breeze around the car slowing down, and therefore exerting more drag on the car.
At the same time, this is a rather ingenious way of creating a virtual toll for roads. If the power gathered is then invested into a public transport system, then you'll end up having drivers subsidise public transport. The fuel savings with public transport may well offset the extra fuel burnt through the turbine induced drag.
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Uh, is it me or does this just seem like a bad idea. Using cars (that use combustion engines about 30% efficient) to move air and then use turbines to convert part of that to energy. .
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A more aerodynamic car will use less fuel than a less aerodynamic, but otherwise equivalent car. You would want to reward owners of such cars. Of course, this is a very round-about and inefficient way to do the same as a fuel tax. If only Americans were not conditioned to reject any proposal with the word "tax" in it...
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And, even if someone does the math behind it and proves it won't work, do you think the government will listen to the logic? No, they'll just go ahead and do it anyway, because the politicians "believe" in
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At the same time, this is a rather ingenious way of creating a virtual toll for roads. If the power gathered is then invested into a public transport system, then you'll end up having drivers subsidise public transport.
That's a great point I never would have thought of.
The fuel savings with public transport may well offset the extra fuel burnt through the turbine induced drag.
I'd be shocked if the energy extracted from burning extra fuel in cars on a freeway would come close to what you'd get by burning the same fuel in a properly designed power plant (and I'm quite confident that the emissions would be worse).
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Re:Drag? (Score:4, Insightful)
The wind in the (been-shot-down-before) turnpike story is a draft caused by the cars' motion, and benefits their efficiency because it acts like a slight tailwind for each vehicle. Eliminating that tailwind would have a large energy cost, compared to the minor harvest from the turbines.
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You mention Texas, where we are well on the way to eliminating all that stupid waste. Some new toll roads are completely automated, with the drivers being given the choice between a pre-paid transponder or bill-by-mail based on license plate recognition. That's going to be taken to the older toll roads within a few years.
Also, the "free" in "freeway" refers to freedom from stopping, not "free of charge", except in a few states.
Drag's not the full story. (Score:5, Interesting)
In other words, if the car drag is causing a wind of sorts, that wind would normally dissipate its energy as friction against the surfaces it blows along - causing the energy top be lost as heat. Now we're just providing an alternative energy soak that extracts the useful enrgy.
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I hope they install treadmills for the pedestrians, too.
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The turbines will increase drag on the cars, which will increase the amount of fuel consumed, which will result in higher emissions from the vehicles in the area immediately local to the generators. Anybody who's ever felt the car speed up when a tail-gater leaves your slipstream to overtake is familiar with the effect.
The question is whether the additional pollution due to the turbines is more or less
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In the middle, between the opposite moving traffic is a turbine effect anyway. Harnessing this will not in
Re:Drag? (Score:4, Informative)
I am a physicist and had the same thought.
Without a doubt, the turbines will interfere with laminar flow, increase turbulence, and increase drag.
I have no idea if the increase in drag will dominate over the increase in efficiency by reclaiming lost energy, but it's definitely something that should be studied before implementing this kind of system on a large scale.
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There's no such thing as free energy, right?
Indeed! There is, however, such a thing as wasted energy.
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-mat
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Engaging the dynamo on a bicycle makes pedalling harder. A bulb failing makes it easier.
The end result will be to increase the fuel consumption of cars using the stretch of road. It's absolutely not free energy -- it's paid for by the motorist.
Don't know what fuel costs in the states but here in the UK, we are already paying the equivalent of over US$2 f
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There's plenty of "ambient energy" in the environment to harvest. The power of waves and tides has a lot more energy than the draft from a Taurus.
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I fail to see how there's any energy cost to cars at all--I don't think the highway actually recaptures any of the otherwise wasted "breeze" energy. To use a boating analogy, (because it's easier to see moving water than air) a boat creates a wake behind it from the water it's pushed out of its way. The waves created ultimately dissipate or hit shore. If I strung up a bunch of power generating buoys along major boating lanes, they'd capture some of the energy that would ultimately have just hit shore. T
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However, I'm not so certain that turbines in the median would have that great an impact on the tailwind for cars in the traffic lanes. What happens normally to that tailwind? It is funneled upwards, into space above traffic, where it dissipates. Without a full analysis, there is no way that any slashdotter could say whether the turbines would increase drag on traffic, or whether they would simply reduce the amount of wind ener
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Yes: Drag. (Score:5, Informative)
The stream of cars generates an air motion along their path. Like geese (though through a different mechanism) the leading cars reduce the amount of air drag experienced by following cars. This improves their fuel economy. (The phenomenon is even more pronounced with semi-trucks. "Drafting": following another truck closely to save even more fuel, is a common practice.
A smooth central barrier separating the two directions of traffic improves the situation by letting the two sides of the freeway have separate airstreams traveling in opposite directions. The barrier reduces energy lost to turbulence, improving the airflow.
Replacing the barrier with turbines will suck energy out of the air streams on both sides to generate electricity. The result will be to decelerate the airstreams that had been giving following vehicles an advantage.
While some of the power comes from captured crosswinds and some from capturing energy that would have been lost to turbulence anyhow, a large portion of it comes from increasing the drag on following vehicles by putting friction on the "following wind": Fuel economy for the trailing vehicles in a bunch is reduced to something near that of lone or leading vehicles.
But there's plenty of power to be had higher (Score:5, Informative)
There's PLENTY of power to be had WITHOUT disrupting the traffic airflow and canabalizing the fuel of the cars.
A freeway or toll road is a clear area and there will be plenty of winds ABOVE it that are essentially unrelated to the airflow near the ground. They're also faster - with energy going up with the CUBE of the airspeed.
By building a wind turbine that starts significantly above the ground the turbines can avoid disturbing the flow at traffic level while collecting plenty of energy.
Also: A Darrieus wants linear airflow THROUGH it. It would be great for salvaging power from crosswind, but rotten for snagging power from opposing winds on the two sides of its axes.
And they're a major hazard: Darrieus turbines fly at tip speeds of about 7 times the wind speed and their narrow blades experience drag loads about equivalent to a wind barrier with a cross-section the size of the swept area - reversing twice per rotation. This has tended to produce fatigue in their materials, sometimes ending with the mill coming apart in high winds some years after construction, with massive pieces flying around at a goodly fraction of the speed of sound.
A savonius-derived design (like the Sandia configuration) would be a better choice. Though it only collects about 2/3s as much power for a given swept area, it rotates at about an eighth the speed and has broad blades that can be much more solidly constructed.
Re:Yes: Drag. (Score:5, Funny)
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All motors draw more power when you put a load on their rotor.
Consequently, a fan would draw much less power if placed in a vacuum (because it is not pushing any air).
As another example, consider a paper airplane that aerodynamically glides to the ground. If you put a propeller at the front of it and try to generate power using it, it will create drag.
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http://en.wikipedia.org/wiki/Betz'_law [wikipedia.org]
50% ain't bad anyway. It beats many other common energy transformations. Your average automobile is probably only 10% efficient.
Finally... (Score:5, Funny)
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yawn (Score:5, Funny)
That's boring. Wake me up when they can power a light rail gun.
Why's the train not running? (Score:5, Funny)
The barriers are supposed to be solid. (Score:4, Insightful)
Re:The barriers are supposed to be solid. (Score:4, Interesting)
I wouldn't be worried about the turbines failing to separate the cars (assuming they were built solidly); I'd be worried about cost. Jersey barriers are surely much cheaper and more durable than turbines, and I think the cost of turbine repair or replacement after the inevitable accidents would be enough to make this proposal uneconomical.
meant to be masssive, turbines not so much... (Score:2)
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"Jersey" barriers are designed so that a tire striking the bottom of the barrier will push the car back into the traffic lane more easily and avoid a rigid collision in many instances.
River (Score:2)
People can fly? (Score:3, Insightful)
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Both the LACMTA Green Line and Gold Line have significant rights-of-way in the center of Interstates. People seem to have no problem getting to the stations.
Hint: think pedestrian bridges and stairs/elevators.
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It has many of its stations right in the median of Interstate 66, which is a busy stretch of road. The way the stations are laid out is that the platform is in the median, between the metro tracks. There is a little building in the median to shelter the platform, with an escalator up to a second level. This second level (which is probably 3 stories off the ground if it were a normal building, at least) has pe
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An excuse for speeding... (Score:4, Funny)
EMR (Score:2, Interesting)
"New" Jersey Barriers (Score:5, Informative)
Dumb idea - way too small (Score:4, Informative)
Wrong answer. Too many little turbines not generating enough energy each. Worse, gearing a number of turbines together when they don't get uniform wind pressure means some of them are just sources of drag.
Progress in wind turbines has been through scaling them up. The 50KW - 100 KW machines of the 1970s never paid for themselves. Somewhere above 500KW, the economics start to work, and farms of megawatt and up machines are quite profitable. Here's General Electric's 2.5 megawatt wind turbine, [gepower.com] which is typical of current large wind turbines. Total worldwide wind generation capacity is about 75 gigawatts. Wind power is now a serious energy source because, at last, the units are big enough to generate serious power.
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Wind power is taking off - China is set to double the worlds installed wind power units within a couple of years. It still has problems like a small unit size and a short maintainance shedule - although with the two problems together it can mean that if you have a big farm of the things you don't lose much of the total when a unit is down. The real saving is you can burn less coal while the wind is blowing. The really big advantage is you can have a lot of s
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Why in blazes would you gear them together? That makes no sense whatsoever. Just dump each turbine's output onto the power grid separately. You could use DC turbines so there's no phase synchronization problem, then convert to AC at the end of the line, or since the power is being used locally, ditch the AC altogether.
Why aren't we moving towards electric transport? (Score:3, Interesting)
Wouldn't it make sense to say that all parking lots should be covered at least partially by solar panels? This would not only add juice to the grid but help reduce the local heating problem with asphalt, reduce temperatures inside cars (thus reducing energy used to cool them), and provide a convenient place to plug them in.
Would it cause to much pollution to make that many panels? Are electric cars truly that much more expensive? Or are lobbyists once again trying to ruin our chances of survival so we are nearly forced to keep spending money at their gas/hydrogen/soybean oil stations?
Re:Why aren't we moving towards electric transport (Score:2)
Take a regular hybrid vehicle. Plug the batteries into the wall.
Amazing, you can now charge the batteries at home, and when you go for a drive you can opt not to turn on the petrol engine.
If you need to go a long way, you turn on the petrol engine.
Cheaper than petrol and less polluting to our cities, and you still have all the range of a petrol vehicle.
So how much do these hybrids cost? About the same as a regular vehicle.
Great, where do I
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Are you honestly trying to suggest that the western world doesn't have a sufficient power grid to support electric cars?
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Yeah, that's why car manufacturers never make new models, they don't want to obsolete their old ones...
Face it, hybrid cars are expensive and impractical. They take too long to charge up, and they don't last long enough. For people without garages/driveways, there is no way to charge them up either.
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Except, for , y'know, DRIVING THEM AROUND.
Idiot.
Re:Why aren't we moving towards electric transport (Score:2)
It's not and either-or kind of thing. While Shell and BP researches whatever they want to do, other researchers working for other (private or governmental) institutions are free to research whatever they want.
Re:Why aren't we moving towards electric transport (Score:2)
Heat water instead (Score:2)
Probably not - as other posters have pointed out. But since that tarmac gets extremely hot, you might as well run a load of pipes underneath it and make some nice scalding hot water.
You'd at least get enough for the parking attendant's cup of tea
We really need a new tag... (Score:2)
Something similar in London? (Score:2, Insightful)
My first thought on seeing a picture of the NJ turbine
Rediculus (Score:5, Funny)
Correction to Original Message (Score:2)
A HUGE GAME REFERENCE IS APPROACHING FAST (Score:2)
Or three-screen arcade shooters [wikipedia.org] for that matter.
Say, if they build a few Darrieus turbines and promote them with Darius arcade machines powered by them, will kids appreciate the power of wind? Will they simply be nonchalant about it? Will our heads explode from all the homophones? In the words of Lex Luger [youtube.com], I dunno!
A far better idea than sapping cars' energy (Score:3, Informative)
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Furthermore, what obligates one to silence one's voice j
The more successful it is, the more it fails (Score:2)
Surely a slightly more practical approach to green energy would be to bar the New Jersey Turnpike to cars that do less than the average mpg? (Note this cunningly moves the
Add this to the turnpike as well (Score:2)
Sounds good, except it's New Jersey (Score:2)
So I imagine that any NJ-based generation system will either use more energy than it produces.
Redundant way of charging people (Score:2)
So instead of something so elaborate, just charge a toll of 5 cents or something for the cars. Same effect, much less complex.
Newsflash! (Score:4, Funny)
television remote power source .. (Score:4, Funny)
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Try again! You're right it's a modification to a Jersey Barrier, but this Jersey Barrier is in NJ on the New Jersey Turnpike.
Summary:
*New Jersey*, home of the eponymous Jersey barrier, is considering wind turbines powered by the breeze generated from traffic
Article:
*New Jersey* highways to be used as a power source, Governor made an offer he couldn't refuse
Have you seen that "systems analysis"? (Score:3, Insightful)
Have you seen that particular "systems analysis"? I have. It's so blatantly flawed that the flaws are almost certainly intentional.