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Wind Wheel Under Grille - Extended Range Innovation -

So I was looking online at electric cars and their range and then I started to think about the wind resistance cars get on the road and how that could translate to creating electricity. I got to thinking on the model S they could place a long narrow water wheel shaped wind turbine across the bottom front end bumper so that as air passes through from wind resistance it charges the battery as it moves along to create a self sustaining system by adding to the current range of the car. The Germans have started testing using wind charging as a stop and go technique in Australia but I got to thinking that it would make more sense if Tesla made an aerodynamic wind wheel located under the front grille. There are light weight materials you could make it out of so it would not slow the car and cause drag such as carbon fiber or aluminium e.c.t.

Just thought I would provide this idea to Tesla I am in college now and am getting to be a bit creative when looking at ways to improve things. Hope someone has a look at this idea and feel free to ask any questions !

The slowing and dragging has little to do with the weight of the materials. Friction and thermodynamic inefficiencies and conversion losses mean you never recover the energy put into "pushing" the fan ("wind wheel") through the air. And all that energy came from the very same battery you're trying to fill.

I have a deal for you! A crisp new $100 bill for only 6 old wrinkled $20s. I can supply as many as you want.

Nice thought experiment for any college attendant:

A volume of air sits still. Kinetic energy is zero.
A car passes though that volume, making air swirl. Kinetic energy is transferred from the car to the air.

There is no way to gain back more energy from the air than used to move the car, since the energy content is zero at the start.

Enter Model S version 6.0 with a sub-zero Cd (just a few years from now...), passing through the same volume of air. Now you have a thought experiment! :-)

This is another example of how the Model S would get better range in stop and go traffic than on the highway. On windy days, when stopped, you extend a wind/electric generator. Before you go, retract it. What could be more fun!

Innovator93, when you get to your Physics classes you'll note devices of this type violate the first and/or second laws of thermodynamics.

Simply, you expend energy to drive the car forward to generate the "wind". You collect the wind energy imperfectly since your fan and generator suffer from friction and losses in the generator. You then put this back into the battery suffering losses in the charging process. You take energy out of the battery to drive the car forwarward with the motor suffering friction losses, inefficiencies in the motor, etc... This generates less wind, etc, etc... Keep repeating the cycle. Energy leakes away to heat with every iteration. Entropy must be maximized.

Just one cycle probably has a total efficience of less that 40%

Kind of sad, but not only can't you generate power, you can't even break even. Entropy must be maximized.

Stationary wind generation does not violate thermodynamics because the energy comes from the environment. Even that is subject to thermodynamics. Ultimatly the entire process is driven by nuclear processes and friction from gravitational attracction but that's still maximizing entropy.

Do you want to change "Entropy must be maximized" to "Entropy must increase"?

Hopefully we, as life itself does, can find ways in which entropy is increased minimally.

I believe that airplanes are equipped with wind turbines. In the event of a catastrophic failure, the wind turbine is deployed beneath the fuselage. The turbine then generates electricity to run the essentials of the airplane.

Yeah, if they were smart, they would deploy wind generators on jets. Since the jets are flying so much faster, just imagine how much electricity they could generate!

EdG. I could go with Entropy must increace.

Stephen, if so, any power gained is offset by a larger net loss of kinetic and potential energy. Drag from the turbine would slow the airplane (kinetic), resulting in an eventual decreace in altitude (potential) I say this only to help our young student not get his hopes up.

I believe commercial aircraft have APU's (Aux power units) that are turbine driven generators running off aviation fuel from the aircraft main tanks.

Mycroft,

Electrical energy generation on aircraft from turbines would be enough to supply major power to the grid, but is offset by the aerodynamic drag of the tied together extension cords hanging off the tail of the plane.

But I think I just figured out why the turbine wheels give the car extra range.

Even if we could break the thermodynamics laws, no fan is going to provide the 0.3 kWh/mile required to keep the the batteries topped up. Do the math.

Inovator93 keep that idea on mind. You can't achieve a perpetual motion machine(laws of thermo and all those things), but I imagine you have a point if you see the idea with the same concept as the regenerative brakes. (A way to recharge partially the batteries)

The fan could generate a current, and they'll have to study if it's efficient or not. Maybe the weight of the fan could increase the consumption of power more than the fan can generate, or maybe not in which case will be a good innovation.

Weight is irrelevant. If the fan is attached to the car, the push of the wind is also a push on the car. Then you start wasting energy getting the spin-generated % of that push into the battery.

Guaranteed loser.

Innovator93,

The energy density of wind is rather low. If you really want to get usefull power, you get it from the drive train. A luxury sedan at speed has a lot of kinetic energy you can recover when you decelerate.

Tesla deliberatly chose not to use hub motors for a couple reasons. Total weight particularly unsprung weight, difficulty with making hub motors for alternating current, cost of having 4 motors, etc. It would have given all wheel drive, and all 4 wheels would regen.

In the Tesla, only the back wheels can regen. Braking on the front is friction only. I'm guessing the Tesla will attempt to regen on light braking, but eventualy the front calipers come into play then it's lost to heat.

Driving in reverse however.... Now that will charge the car. (kidding)

Time to stop this nonsense of a wind turbine refilling he battery. The arrangement is another example of an impossible perpetual motion machine of the simplest kind and will not provide more energy to the battery than is extracted from the battery to accommodate the additional load of the turbine. For every Watt generated by the wind turbine the motor has to put out more than that Watt to move the arrangement through the "wind". Further, even more power than that has to come out of the battery to drive the motor.

If you still believe in the possibility of this wind turbine arrangement working, then you would be much better off, and not require any additional equipment, by simple stepping on the brakes while driving with your foot on the pedal and using the regenerative braking to supply the battery. This, of course, is ridiculous, but not more so than the perpetual motion machine arrangement. Time to learn some basic physics.

I believe Tesla has decided, for simplicity of design and, therefore, reliability, to do regen only when removing your foot from the accelerator. Braking is simple braking.

The level of regen you get when lifting your foot may be programmable.

Zelaza, back off and bug off. For the umpteenth time, Innovator brought up a perpetual motion/free energy scheme. They've all instantly been shot down. This thread is actually a rehash of many others.

Your self-importance is seriously undeserved.

EdG;
There's an xkcd for every situation. I think a year or two ago I started at the beginning and read them all. My fave may be the one with our hero facing a dude standing in mid-air, who says, "The universe does NOT work the way you think it does." Or WTTE.

;P

Just read over this and confused. Who cares if the wind turbine wouldn't charge the car back to full battery? If you were able to install a light wind turbine into the grill of a car, or spirals along the side inside of vents, wouldn't it be able to partially re charge the battery and extend the number of miles that you can drive on a single charge?

@hey: Yes and No.

Yes: If the car is parked on a hill facing into the wind, the wind could recharge the battery, just like any other windmill.

No: If the car is moving and there is no wind, then the turbine adds drag and the amount of energy generated would be less than the energy used by the car to create the relative wind due to the extra drag. Net loss of range.

Theoretically, a windmill that was oriented perpendicular to the direction of travel and was enclosed in a fairing that minimized forward drag could generate some energy from winds that crossed the path of travel. This would be what I call the sailboat effect. I doubt it would produce enough energy to make it worth doing, however. Think about only running the car using the prevailing winds, like a sailboat, and how much "sail" you would need to make it useful. :-)


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