Make:

• Single-Wheeled Bike Trailer
• LED Costume
• "Self-Carving" Pumpkin
• Wind Tree will turn wind into turntablism
• How-to: Cast concrete planters using packing inserts
• Old iBook finds new life as lighting

"My catalyst proposes to retroactively collect royalties on the land taken from social interaction."

If you can put together a sentence like that, maybe you should be getting your law degree instead.

What makes you think that "turbulence" exists at a reasonable elevation above the road, that is capable of doing a significant amount of work? Just sort of guessing and assuming?

What a stupid idea! If the traffic can turn the impellers then there will be dragging effect on the traffic causing them to be less efficient using more fuel adding to global warming.

I've often thought that the median of highways would be a great place to put turbines. It never occurred to me to suggest that passing cars might actually power them.

Couldnt we just cover the outside of the car with small wind turbines, charge a battery....

Another idea that looks good until you do the math.

D'Oh!

( 10-4 whatevereverever + ironstine!)

The concept is good, but everyone is right.
As the great bottlecap said:
"Try again. Please drink more Dr Pepper."

The only way to get free power is from the elements,sun,wind,waves etc you can't power one machine to power another, you get owt for nowt.

How does this force the car to do any extra work? The energy has already left the vehicle in the form of turbulence, the idea is just to recapture some of that. If you place a solar cell next to a lightbulb does the lightbulb draw more current? While I really don't think this idea is practical, it's still a pretty cool idea.

While I agree that the turbulence caused by traffic probably isn't enough to propel the turbines I do think its a good use of exisiting real estate and if sited correctly in windy areas could generate some energy.. Maybe if you think on a smaller scale you could use it just to power some local traffic signals,street lamps, signage illumination. I don't think we should be too hard on the conceptual thinking process here, good ideas come from all over the place.

I saw an article in popular mechanics (it's gotta be 10-15 years ago) that talked about this idea. It had 6 foot tall savonius rotors placed in the center barrier that could be spun by traffic passing on -both- sides. The article had a drawing with them all the way down a highway sending power to an "electric station" at either side to capture wasted energy (making the electric cars more efficient). Back then I thought it was a really neat idea making use of both directions of traffic in one single rotor.

2nd law of thermodynamics. 'nuff said.

I'm not sure what the weather is like in Arizona, but here in the mid-west there is enough wind on the freeways to push your car around. Basically if you have a big strip cut in an area of trees you end up with a wind tunnel and while I can't comment on the turbulence from cars other than the effect of a passing semi, I'd say the natural wind in these areas would be a fantastic power source as long as the turbines are stable and don't cause too much gawker delay.

TheThompsonFive, as for how this requires a car work more...

These things rely on apparent wind created by a lot of car motion (one car is likely not enough). You get a corridor where airflow is traveling with traffic to some extent. This, of course, assumes there's little to no outside forces (such as wind).

By putting a restriction on this corridor, you take away the advantage that you've been given by all of those cars ahead of you... So more force is required to overcome aerodynamic drag. Yes, "wind" pushes the turbines - but indirectly, the car does the work.

Kind of like a truck full of birds - if all the birds take off and fly inside the truck. The truck still weighs the same. The birds still have a force down on the truck -- but indirectly through air ;)

trebuchet03: All that said... highways tend to be open areas -- which, to me, seems like a prime location for a wind turbine not powered by cars :p

Also where embankments might funnel surface winds to usable velocities.

Of course, any gains in energy captured by these rotors will be lost due to all the wasted gas of people driving around, lost, due to the sudden lack of road signs.

TheThompsonFive said:
How does this force the car to do any extra work? The energy has already left the vehicle in the form of turbulence, the idea is just to recapture some of that. If you place a solar cell next to a lightbulb does the lightbulb draw more current?

If you block the light coming from the bulb with a solar cell then this will decrease the amount of light available to illuminate whatever the bulb is lighting.
So to keep the amount of illumination constant you will have to either add another light or increase the light coming from the original bulb therefore increasing the energy used.
QED

trebuchet03, I can see this if the cars were traveling in a tunnel, the more hindrance to the turbulence escaping the harder it is for the car to displace more air as it travels forward, but out in the open like this the turbulence is radiating away from the car unhindered and the turbine is catching it as it passes by. I can see it's going to take a simulation run at the Los Alamos labs to settle this one.

And yeah, better make sure everyone has GPS before the signs come down.

jihgo, Yes, but what if you weren't trying to read the paper over there. I'm not saying this energy isn't coming from anywhere, just that it wasn't doing anything useful. What if I made a machine that converted the noise from the cars engine into electricity. Would the car have to use any more energy to drive past it when the machine was on than it would if the machine were off?

A better idea would be to put piezoelectric panels under the road surface that turn the pressure of the vehicles passing over them into usable current. They already have floor systems that create usable amounts of power from people walking on the floors of skyscrapers, why not recover some of the energy of all of those vehicles driving on the roads?

Thermodynamics says it won't by any stretch equal the energy it took to move them in the first place, but it would reduce the amount wasted by recovering a portion, much like regenerative braking in an electric car returns a portion of the energy to the batteries.

Some detractors of this process say the energy conversion from the piezo system would "rob power from the cars, and decrease their gas mileage", but this is hooey. The cars are already putting the energy required to move them into the road surface as angular momentum through the tires. It becomes kinetic energy in the cars, and randomized heat in the road surface. This system simply converts part of it into electricity instead of wasting it as random heat. It's the "equal and opposite force" that is being converted, not anything additional.

A Duke University document shows some of the background on the piezo and electromechanical devices proposed for these mechanisms: Piezo Flooring - Warning: Word Document

This might not be a great idea but at least there is no energy being wasting from the small amount of wind created as the motorist speeds going pass. Great comments everyone. I think that the creator could have been more clever if the invention was place vertical then horizontal, with atleast a 100m span. using light material That could catch maybe a little more wind.

Subscribe today, save 42% and get web access to MAKE free. MAKE Digital Edition is available only to subscribers.

$34.95 / 1 year
(4 Quarterly Issues)

Subscribe now