This won't reduce the mpg cars get, will it? If not, it seems a good way of recapturing waste energy. Not actually renewable energy though. Just getting more useful energy from a gallon of gas.

"This won't reduce the mpg cars get, will it?"

What people often forget about wind turbines is that they are not the only thing that are in the way of the wind. Everything else is: trees, buildings, billboards, hills, etc.

So unless we make everything completely flat, I don't think a few turbines will make much difference.

As the previous poster said, this is just a way to extend the efficiency of a gallon of gas. Since the wind is being generated by an internal combustion engine it is not free by any means.

there will be times when the natural wind supplements the car effect wind and that would have to be calculated into the overall efficiency and energy generation calculations.

You have to remember the efficiency of the turbines themselves since they don't transmit 100% of the energy they generate to the end user... so once you have the total amount of energy generated and how much the highway system is going to cost one has to wonder if that cost is justifieable or does it make more sense to take that money and increase the average mpg of all cars and build wind turbines in places of high natural wind?

They would have to be mighty close to the cars and trucks to capture the turbulence from them. Even then it might not be very effective. Vehicles are designed to cut through the wind and leave minimal turbulence behind. What about cross winds too? Not all highways would be candidate for these, but I can see them in some places. Why not put a wind turbine on cell phone towers?

This is not the same as the ramp. It's like two racers drafting off each other. It makes the whole system more efficient (unlike the ramp which is part of an at-best-zero-sum game). Probably not worth the installation cost, though, for the reasons mentioned above. Furthermore, the 10 mph figure he cites is at a much higher altitude than he's imagining the turbines, and statements like "I believe that the wind stream created over the freeways by our primary mode of transportation will create an average annual wind speed well beyond the baseline of 10 mph." sound wildly uninformed.

WOW. A fine job from a student designer. This is a brilliant idea, make sure you get all the royalties from this design, dont let anyone steal it from you. Congratulations, and thank you for not being another designer that creates landfill for the earth.

~Sean

At a minimum they can be used to power the lights at interchanges or part of the energy at tollway oasises.

Even though it could be a good idea, if the turbines were mounted on the already existing structures for signs (optimising the use of the structures!!! I would never make new structures for this kind of thing), they should be vertical, not horizontal: This way they could only use that tiny bit of suction from the trucks (see above comments), but the wind would have to be in the direction of the highway for the turbines to be really as efficient as possible...

Making good use of what's already built, this idea would probably be more viable at electricity-powered railways, which has a lot more of those poles and is usually away from buildings and other stuff that might be in the way. Also, the power lines would already be there, which is a win-win situation.

I have always wondered about a similar idea... however I always thought about placing wind turbines in tunnels. Especially subway tunnels.

Or small vertical turbines in the median between opposing traffic.

This might work nicely in a few settings.

As always there are praactical concerns:
Liability for damage and accidents;
restrictions on over-height vehicles
will prevailing winds be in opposite directions and reduce energy generation;
are the poles a hazard to traffic or will they have to go onto private property;
is the distance to where the electric lines will tie into the grid or be used so far away as to make this overly inneficient;
could the same investment in a typical pole mounted wind generator provide more power?

So, not for every situation, but a truly innovative approach.

We have 'jet-fans' in our tunnels, to evacuate smoke and pollutants when there's a fire or traffic jam. You can see them spinning idly when you drive by. I don't think that there's much useful energy to be collected from them.

It could be interesting to see is road geometries could be modifed and wind generators placed to maximize generation potential.

But I know that in tunnels the air is mainly moved through by the 'piston effect' of the mocing cars. If anything reduces that movement there could be a fall off in pollution abatement, as well as increased fuel use as parasitic drag would increase.

Very original and interesting idea, and might even be very useful in future

This is a great idea. The problem comes when you consider the true def. of a green product. Don't forget that the mechanism generating energy has to produce more energy than what is required to produce the object!!!! If you evaluate 90% of the ideas formulated you will find that the initial manufacturing process required to create not only the product but the machines that make the product create a negative energy displacement that will never be overcome by the product itself. Therefore NOT GREEN.

Jon, riffing off your piston-effect, parasitic drag comment.

Flip it around. Instead of using the movement of the vehicles to drive the turbines, use the turbines to absorb energy from oncoming wind. For those vehicles driving into the wind, efficiency would be significantly improved.

Here's where this idea has value: Truck lanes coming down mountain passes, such as Siskyou and Tejon passes on I-5 in the west coast. Trucks coming down these passes have too much energy, and not only is it wasted, but the way in which it is dissipated is both dangerous, in the form of overheated discs, and toxic, through scorched tire rubber. Harvesting this energy through banks of turbines would recapture energy that is now wasted, and would also make trucker's jobs that much easier and safer.

Elsewhere, I fail to see this or the earlier ramp generator being worth the price of admission. It would be unadulterated flim-flammery to install these anywhere other than descents, and even then, they would be in direct competition with the energy recaptured by regenerative braking systems.

Like the earlier ramp generator, this could be useful for regulating

I have found a way to get the trees in a treed yard make enough power to make a house work
It does!!!
And it don't cost much!!

You can call me nuts, But it works
Just harnice the tree wind eneergy....
Want to find out!! e-mail me