APR 05

OMG, this is a great idea. Anybody who has ever ridden a motorcycle down the highway can attest to the power of the wind buffeting you as you speed along. Right off the top, a couple of logistical concerns: these look like they might be somewhat high maintenance, and there's also the issue of wildlife, which already, as we know, takes a pretty ugly beating on the highway. Regardless, great idea!

Janis Mara
www.ecotality.com

This idea is simply incredible. But it wouldn't be able to work all the time. What about those times when traffic is stopped, bumper to bumper? Or when there simply isn't enough traffic to generate enough electricity? Obviously the designers have already taken those two things into account, but the answer would still be interesting.

I'm not sure what the maintenance on these would be. Obviously there's more grit and dirt flying around next to a roadway than there is for a turbine perched up 100 feet off the ground. But a well designed mechanism could probably deal with a lot of that, to prevent premature wear and failure.

I don't think wildlife would be any more of a problem than in a traditional condition with a 'Jersey barrier.' The image here shows a cutaway view, but there shouldn't be critters getting into the works.

I don't think the idea of this is to provide a continuous energy supply. During extremes of traffic (congestion or absence) it wouldn't generate anything, probably. But when traffic was moving, the electrons would be flowing.

Say you could generate 1 kW with one of these and they were 30 feet long. You'd have nearly 180 of these per mile, if there were no interruptions, so that could be roughly 1 mW per 6 miles. I have no idea if those numbers are anywhere close to accurate, but that can give you some ideas to start thinking about with this.

How about putting those on railways or subways?
I think they push a lot more air. Anyone can feel it while standing in a train or subway station. And there are no traffic jams in there.

I've had my eye on vertical axis wind turbines for some time now, it's nice to see that I'm not alone... Though this concept is much more "interesting" than any of mine!

- www.JoeLevi.com

One would have to take into account the amount of punishment the "Jersey Barrier" could take. If an 18-wheeler slams into it, is it going to crumple like paper? Regular barriers are made of reinforced concrete for a reason.

Is this power generated by putting additional resistance on the cars making the cars use more gas?

Aren't barriers called "barriers" for a reason? So what happens when the car decides to cross over into oncoming traffic?

Apparently nobody has ever heard of The Law of Conservation of Energy. The wind driving these turbines isn't just free energy floating around in the air. It's caused by aerodynamic drag on the cars moving through the air. That energy is coming from somewhere: the gas tank of the cars driving past the turbine. It would take more energy to push a car through the air if that air meets more resistance from a turbine. Of course the energy transfer is horribly inefficient and probably only represents a tiny energy loss on any one car. But multiply that times millions of cars it takes to generate any significant energy with this turbine, and it's a huge energy burden to place on innocent drivers. It would be more efficient to just use that gasoline to drive a generator.

Good idea, but not new. I saw this same thing on an old show (I think it was on the Discovery channel) called "Beyond 2000." It was at least 12 years ago. I don't know why it wasn't pursued though.

Why not have rollers in roadbed that turn turbines in a properly sheltered housing?

And atop the dividers, put small solar cells to soak up solar energy even when the traffic is slowed down and bumper to bumper.

You know, that highway divider is a good idea. 8)

Charles is right, curious. And your proposal is actually worse in that regard.

Michael might be on to something, tho'. Patent it, quick!

Charlie is an idiot. The cars are already pushing that air around, the air just bouncing off of the barrier and hitting the car again. This scheme does not add one iota of resistance to the car that it doesn't have now. If anything by absorbing the energy of the air less air bounces back to the car.

Great Idea.

1. Jersey Barriers are there to stop tractor trailers from entering on coming traffic. The luvers must be designed to replace the reinforced concrete it replaces.

2. All the equipment must withstand salt and other debris.

3. How does the cost and amount of engergy generated compare to placing solar panels on the sides to have the windmills inside?

@malcontent: I don't think Charles is an idiot. He raises a valid point that merits some investigation. Let's start with energy. The cars expend some energy over and above the energy required to move the car in a vacuum to move the air out of their way. Those air molecules, then, have some amount of additional energy causing them to move around this way and that. When the air molecules encounter a standard Jersey barrier, they impart some of their energy to the molecules of the barrier, heating it by some small amount. The rest of the energy is used in moving the air molecules in some other direction after they bounce off the barrier.

So here, the air molecules already have some energy they wouldn't already have had by being hit by vehicles moving along the road. Some of those molecules will hit other vehicles, and those air molecules will cause the vehicles that they hit to again expend extra energy, and the cycle repeats itself.

Now consider miniature turbines in the barriers. For the moment, let's set aside concerns about debris, dirt, and rain clogging up the works, The air molecules, as above, gain energy from the cars. Some of the air molecules impact the turbines, and those air molecules impart some of their energy to the turbines. The turbines spin, and the air molecules flow through to the other side, some of their energy removed. These air molecules are going to hit the vehicles on the other side, and again gain energy, pass through the turbines, and so on. I don't think that the air will thus have an increased resistance - to the contrary. The turbines will have removed some of the energy from the air, makng the air *theoretically* easier to move through. Gas mileage would improve on both sides of the barrier, though I don't know if it would improve noticeably.

So if my thinking is correct, Charles is mistaken. Regardless, he is not an idiot.

Though it's tempting to think that this is a push, conservation of energy and all, it's not:

This design is specifically for use where there is already a solid wall. Replacing the solid wall with something slightly less solid will actually *reduce* the amount of energy that it takes cars to push the air in front of them out of the way, not increase it.

If, today, a solid concrete wall is in place, the car must push the air to the side, then compress the air between itself and the wall, absolutely. This simply introduces some holes for the (already!) compressed air to escape through, and capture the potential energy in the compression wave.

This is a totally unfeasible idea. While novel, it won't work because it won't generate near enough electricity to justify the building and installation and maintenence costs. Essentially, EROEI is less then zero.

Winds are not sustained either by the movement of passing cars. Sustained winds would be necessary for any wind turbine system.

The decline of oil will also dramatically lessen the number of drivers on the road soon and this too needs to be taken into account, although the EROEI is a total "deal killer". Nobody would ever build or invest in something like this for this reason alone.

So maybe this will work out in southern climates, but up here in MI, they'd be clogged up with snow and ice plowed off the road for several months out of the year...

How much energy and fossil resources would it take to install these?

I share curios' sentiment. I think the only real question with the divider turbines is what it will take to produce them and how dependable they will be to the grid (if indeed they go to the grid). The grid likes projected stability. If you have an accident on the freeway your screwed and that predicted energy is lost.

I think that a roller system would be far more effective if it could be designed so there was very little or no impedance on the forward energy of the vehicles. If you placed a series of very small rollers (maybe 6'' in circumference) that were coated with a grip material and were perfectly in line with the height of the road and were spaced out every 100 feet or so with independent flywheels and connected to a shared generator I think it could generate a fair amount of energy and not impede the vehicles. An ideal place for these would be on bridges and above sewer lines, where it would be easy to install and maintain and the generators to store and send energy to the grid without installing new massive infrastructure to support it.

@Curious, Alex: Do you folks understand how wheels work?
Serously though, tires roll. The reason a car's tire can grip the road is that the bottom surface is momentarily stationary when it touches the road. A car running over rollers would slow down because of wind resistance on the vehicle while the energy from the engine's torque on the wheels would be transfered to the rollers (which would spin backwards). It would be like suddenly coming upon ice... a huge traffic hazard. Plus your tires would be shredded when transitioning back to the normal, stationary road surface.

The jersey barrier thing is a neat idea, very creative. I think the key is to not replace the barriers because it would be too hard to replicate their function with a hollow design. Instead put these turbines somewhere else near high traffic roads. To have a win, you have to be sure that the resource and energy cost to produce, install, and maintain the unit will be less than the energy produced over the usable lifetime of it.

This is an ingenius idea in MHOP. ;)
Hook one of those generators up to my street.
No-one goes under 60mph there anyways.
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This idea looks less complicated....

http://www.inhabitat.com/2007/04/30/student-designs-highway-power/

to the person named "cow"

There is no extra resistance on the cars, it's making use of what's wasted now, already!

In a decade, oil prices will cause astounding paradigm shifts in American society! Expect the automobile's demise, save for entertainment of the Mega-Rich on private tracks! Anticipate "Manhattan Project" sized government initiatives at the end of the next cyclical recession, to build intercity bullet train systems for freight and passengers, and look to airplane flights to be curtailed due to cost of fuel! We are competing in world markets with a weakening dollar for oil.The Asians, our competitors are working in stronger currencies, the "Yuan" in particular! American "Fiat" money will not save us! Internationally, countries are arranging their affairs as to avoid out falling dollar, and some want a new international currency! Disaster for Americans! Disaster! The Chinese "Yuan" will play a big role, as will the Euro, the dollar a lesser role if any! Americans will no longer have cars! They will work from factory dorms for contract periods, then be transported by train to wherever they choose to live for the rest of the year - no automobiles affordable, or needed! Sound bleak? Calculate what it costs you to get to and from work annually! Want that money for your own survival, not the companies shift whims, fanciful locations? Could it help pay down your mortgage? Uncle Sam has his eye on that chunk of change too! Watch out! the big boys play rough when the game gets tough! The Asian facts of life are going to shape our American lives as never before in the next few decades!

What a brilliant idea! I know there's been a couple times where I've literally been knocked over while biking from the wind of a passing vehicle. So there's definitely some energy there.

That is a brilliant idea. I've nearly been pushed off the road by huge trucks...I'm sure they can produce energy!