# wind powered



## briankmc22 (Sep 24, 2009)

ok i know this probably redundant but on my design stages I have been looking for adding drive time...my question is why cant this be done??

My idea: (see shitty diagram below)

Install a 10kw alternator in the engine compartment with a turbine multi cup horizontal design that captures all the air flow threw the grill as the car runs. Ive found a few 10kw alternators and all seem to need roughly 1800 rpm to reach a 60hz output.. Depending on the winding of the alternator I assumed it would roughly take 27-35mph of channeled wind force to achieve this speed....this would create a constant leveled 8-10kw of power that could be cycled either directly to a dual stage controller or to recharge the batteries allowing further juice for items such as power brakes and steering. If I use a rear engine mounted vehicle like a bug I have plenty of room in the front of the vehicle...assuming I remove the gas tank, engine and other uneeded weight with a GE DC fork lift motor rated at 145lbs I am only added another 75lbs to the vehicle with the alternators I have seen...which if I use gold cart batteries I can factor in instead of deep cycle batteries that weigh more... 

ok so the more technical people and not those that see the glass half empty please let me know if you feel this would add atleast a 50% gain on my estimated distance of 35-42 miles range??? Well worth the $600 bucks for the alternator if it does in the long run, 

thanks guys!


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## Qer (May 7, 2008)

http://en.wikipedia.org/wiki/Perpetual_motion


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## adamj12b (May 4, 2009)

Basically what it comes down to is it will not help your range, but hurt it. 

The energy you are trying to generate is coming from you batteries propelling the car through the air. 

The only way it could help your range is when your stopped, there is a very strong wind that could turn the turbine and generate power. Essentially being charger. As long as its engaged while your are driving, it is adding drag, reducing the range of the vehicle. 

Sorry

-Adam


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## briankmc22 (Sep 24, 2009)

ok so let me get this straight... you CANNOT charge the battery then while the vehicle is moving??? Again I am way new to this...but I have one thing that doesnt sit right...when the air is coming threw the front of the car threw the area the radiator normally sits it is used for cooling, since the radiator is now removed that wind will still continue to come threw except hitting the the engine wall between the cabin and the engine bay so this drag would be apparent regardless so wouldnt the alternator deviate that and thus use the already present drag from resistance and hence creating no additional drag... now if a channel was applied that brought the air threw in lets say a duct and dispensed the air out the hood or under the car diverting the engine wall at all this would actually remove all drag that would have been there to begin with and still propel the generator...in example on my boat I have a 24" wind turbine that sits on the top of the boat and when I drive it spins from my movement and produces 400watts of power for things in our cubby and takes the load off the generator hence uses less fossil fuels giving me better gas mileage... that drag was was already there to begin with just now its being applied... so Im trying to apply this same method but in a more controlled environment... i guess what I Would need to do is setup an experiment...drive with a meter and see how much force is generated at these speeds then apply that same wind force from say a leaf blower over the fins to replicate the same level and see what rpms I can achieve...does that make sense


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## Harold in CR (Sep 8, 2008)

Before spending all the time to experiment, go to www.Bergey.com, and see how big the blades are to run a 10KW alternator. It IS one of the most efficient Wind Machines on the market.


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## adamj12b (May 4, 2009)

The problem is the is blowing on the car because the the car is being propelled down the road. In fact, the wind is not even blowing on the car, the car is moving through the air. When the car is moving you are using the power from the batteries. When you add an alternator and turbine to generate power to charge the batteries, you have to add the duct, the turbine, the alternator, and cabling plus mounts for everything. All these things have a weight. So you must add that into the figuring. Basically, what it comes down to, is you will never create enough power to be worth the hassle, or the cost of that $600 alternator. 

Something that is more worth doing is adding an alternator with an electric clutch setup to the tail shaft of the motor. 

http://www.waynesev.com/ev/regeneration.html

That is a much better router to take, and its proven. 

-Adam


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## Qer (May 7, 2008)

You can beat this dead horse until it smells even worse than it already does, it doesn't change one thing. A wind turbine will add drag, period.

It is true that the radiator in an ordinary car will add drag and that a wind turbine might generate some energy out of that drag, but that will be peanuts compared to the energy you'd save by simply covering that hole up which would make the car more aerodynamic.

EVERY step where you convert energy means losses and there's never such a thing as a free lunch. The energy has to be taken from somewhere and that somewhere is your batteries. Ie the energy to the batteries comes from the energy in the batteries after losses in battery, controller, motor, transmission, tires, drag, generator, charger and, finally once more, batteries. 

"Ye cannae change the laws of physics!"

Your example with the boat is wrong and your conclusion is flawed. By using the wind generator to produce electricity when your boat is propelled by fuel is a net *loss*, nothing else. The same energy from a generator connected directly to the engine would be more efficient (of course, assuming that the two generators are equally efficient by themselves) and once more I'd like to refer to that Scotty quote above.

You're of course welcome to experiment if you don't believe us, but you're doomed to fail, at least in this universe where every energy conversion results in a loss. In another universe where energy can be converted with a net gain your experiment could of course succeed, however a universe like that would probably explode eternally making life, as we know it, impossible...


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## Qer (May 7, 2008)

Forgot, there's more bashing of the dead horse here:

http://www.diyelectriccar.com/forums/showthread.php?t=13644

You should probably read that before you try to reinvent perpetual motion.


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## Sunking (Aug 10, 2009)

Simple answer is it violates the First and Second Law of Thermal Dynamics.


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## neanderthal (Jul 24, 2008)

Sorry we sound kinda harsh. I understand what you mean by trying to make use of the wind drag already present. But we have all played with these ideas for a long time and looked at them all from different angles. I know it sounds like we are being cup half empty kind of people, but that is not the case. 

You are exactly right that using the drag already present in the design of the car could recover a little power. And experimentation would be the best way to find out how much. But Qer is right that covering that radiator area would make a WAY bigger difference in range.

Let me explain it better. The amount of energy you put into something is ALWAYS the same as the amount you get out, right? For example, you have a 144 volt battery pack with 100 amp hour batteries. That is a 14400 watt hour pack, or 14 kilowatt-hours (14kwh) Lets say you have a little sports car. Lets say the little sports car uses 250 watt hours per mile do drive at 55mph on flat ground. 14400 divided by 250 is 57.6. So if you were do drive till the batteries were fully discharged, you would have gone about 57 miles. (I know your design and requirements are different, but this is just for the sake of argument.) So to maintain 55 mph, you are drawing 95 amps constantly from you 144v pack.

Now lets say you have ducting and what-not to get the air into a good turbine. You are using the energy that is coming from the batteries to move the blades of the turbine. So if that turbine makes 1440 watts, it means that you are getting 10 amps and 144v to charge the pack with. So lets say your wind turbine is a mega awesome, perfect turbine made from superconductive stuff (which doesn't yet exist). That means its 100% efficient and all of the mechanical energy (from wind) that it get it turns to electricity. So the 1440 watt it gets turns into 10 amps to charge your 144v pack. Well the car that used to take 95 amps to maintain 55mph, now takes 105 amps to maintain 55mph. So the extra 10 amps to charge the battery pack does nothing. And in real life, the turbine is like 70 of 80 percent efficient, so you end up with less range. That is an example of the law of thermodynamics. It is lame, but true.

Now that case that I described is a case where you would have a turbine in a stupid place, like on the car's roof. Your example was different. You are thinking of putting it where the air is already moving and wasting energy, which is smart. But the air is moving slowly there, so you will probably end up getting a very tiny amount of energy. But lets say it works and you are actually charging and extending your range. Adding 1440 watts of juice will add about 10 miles to your range, (and that is being VERY VERY generous. You would not get that much wind (2000 watts worth of wind accounting losses from inefficiency) through the radiator hole). In all likelihood, the wind through the radiator hole would give you maybe 144 watts, so 1 amp of charging on a 144v battery pack. But lets just say it worked and you are getting 67 or 68 miles with the turbine instead of 57. If you were to just close up that radiator hole (in a nice aerodynamic way) it would make the car so much more aerodynamic that you might only require 160 watt hours per mile to go 55. That means you would get 80 miles per charge. (the aerodynamic electric car, the tesla roadster needs 150 watt-hours per mile)

The laws of thermodynamics suck. Oh well. And it works out the same for everything you try. Wind power, generators on the wheels, everything. The case where it actually helps is with regenerative breaking (regen). You have already used electrical energy from the battery pack to get up to speed. If you apply the brakes, you are just turning it to heat energy in the brake pads and rotors and stuff. If you apply a wind thingy, or a generator on the wheel thingy while you are slowing, you are benefiting yourself.

So basically when you do the math, at the end of your trip,(if you finish where you started) if you start out with 14400 watts worth of electric energy, and your batteries are empty by the end, you could to the math and calculate everything and find that the heat you made while driving, + the wind you moved out of the way of the front of your car, + the distance you went uphill and downhill and all that jazz, you get that you created 14400 watts worth of heat energy and air movement energy. 

Clever trick only make you go further if you end up becoming more efficient in the end. Meaning of the 14400 watts you used, a bigger percentage went to moving you around. Pretty much anything you do while cruising or accelerating cancels itself out, doing it while braking increases your overall efficiency.


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## Stunt Driver (May 14, 2009)

10 KW? that would be more than my motor takes on Fiero! Does that mean I can bring some extra charge home after I ride? 



ps. looked in damn physics book - seems like won't work....


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## Sunking (Aug 10, 2009)

There is one way to get a little extra range without violating the law of physics, but it is hardly worth mentioning using solar PV cells in the roof, trunk, and hood. Problem is it would not be enough to amount to anything.


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## Coley (Jul 26, 2007)

I use my old wheel barrow to show how well many ideas work that are brought up about better range on an EV.

You put the wheel barrow out on the driveway, in front of your garage.

Then you hop in, lift the handles and away you go.......


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