New Jersey Turnpike As a Power Source?

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."

Re:Drag?

[arivanov]

Absolutely. This is not a free energy at all. What I find more interesting is that the system uses the same turbine design as Quiet Revolution turbines. AFAIK this design is still under a couple of patents so they will have to shell out a very sizeable license fee. Pity Quiet Revolution is not public, this would have been a good time to play with its shares.

Drag's not the full story.

[EmbeddedJanitor]

The energy must come from somewhere, so it must be ultimately coming from the gas powered car. However, if it is being taken in the right way it is energy that would otherwise be converted into waste heat/sound.

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.

Re:The barriers are supposed to be solid.

[mrchaotica]

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.

EMR

[Essequemodeia]

How outlandish would it be to embed efficient magnets within Interstate roadways while installing similar magnets within cars and trucks? This is just a late-night idea but couldn't that generate a sizable amount of electricity? Perhaps it could be realistically considered once cars are fitted with a workable system for auto-navigation, a system that might require the installation of specialized equipment in existing roadways and therefore offer a justifiable economic solution (as well as an opportunity); one of those kill-two-birds-with-one-stone approach.

Why aren't we moving towards electric transport?

[copponex]

This is a serious question: since virtually all energy comes from the sun, and we have an extensive infrastructure for transporting electricity as well as extensive technology for storing electricity, why are we wasting time on road-side turbines and hydrogen fuel? Obviously, you make adjustments for average cloud cover, available real estate, etc. But it seems silly to me to research hydrogen or whatever scheme Shell and BP (who are completely unbiased research firms) propose rather than leverage existing technology until they provide a real solution.

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:Drag?

[dbIII]

Yes, insightful for a given value of insight - however moving the turbines a short distance away from the things instead of doing something stupid will give you both the wind to spin the turbines and no extra drag on the vehicles. Ducting is also possible to get a lot of wind to the turbines if they are far away without reflecting much back on to the vehicles.

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.

Re:Dumb idea - way too small

[dbIII]

Lots of little ducts can power one big turbine.

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 spinning reserve to bring in within seconds to cover peaks and not push those thermal plants hard and reduce their life. Peaks are really the problem in power generation - not base load capacity. Another advantage is if you need a few more megawatts you can have it in under a year and not in five or ten years like you would need for a thermal plant.

The "wind power is not base load" argument is irrelevant since it gets used for other things. An extreme example is a turbine installed in Antarctica which saves shipping in a few thousand litres of fuel each year and all the hassles involved with keeping a large amount of fuel liquid. You use this stuff to save on fuel. With post 1960 control systems it is not a big deal - you don't have to ring up the power station and say you need a bit more to dig with the mining dragline and to slow down a bit when it drops the bucket and regenerates.

Re:Drag's not the full story.

[olof_the_viking]

I think it would be more energy efficient just to set a solid divider between the lanes, eliminating the counter-flow of the air streams, thereby removing most of the vortices altogether and letting the cars run with less air resistance. It is as a friend of mine says: "the power of the energy in the wind is like an 8 mm high waterfall." Treadmills at the stoplights in the city to power subways or trams would be way more efficient.

Re:Drag?

[schwinn8]

We Americans would be less conditioned to reject new taxes if we had any faith that the money from these taxes wouldn't be wasted on irrelevant or unrelated things. Heck, just look at this idea - where do you think the money will come from? Likely from unrelated and irrelevant taxation of something else.

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 it. Just look at the idiotic change in daylight savings time. For those that didn't know, it was supposed to magically save the country some amount of energy... well, it didn't... and they were told it wouldn't (see: http://arstechnica.com/news.ars/post/20070403-the- daylight-savings-change-no-savings-no-point.html [arstechnica.com]

But back to the original question - it's all about conservation of energy. This energy has to come from somewhere, and it will simply come from the cars. If it's not creating drag on the cars, then it's too far away to be affected by them... in which case, it's just an array of wind turbines using the planet's natural winds.

This is an idiotic idea devised by politicians who clearly know nothing about physics or science.

Re:Drag?

[san]

> It's like harnessing the wake in a channel. The boat's going to make the wake regardless of what it impacts on.

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.