# Attaching a wind turbine to an Automobile? **URL:** \ **Category:** Factual Questions\ **Created:** [October 5, 2012, 12:46am UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757 "2012-10-05T00:46:23Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [October 7, 2012, 5:13pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/21 "2012-10-07T17:13:18Z")
> [@badger5149](#): > > Something I have wondered about along the same lines is using the heat from the exhaust to wind up thermal springs like we use to use on the old chokes and then using the torque stored in the springs to help drive the car. Only problem I see with this is the exhaust would have to constantly switch it’s route to allow the springs to contract and cool. It would likely add too much weight to a car to pay for itself. if we’re trying to extract energy from the exhaust, we’re far better served with turbochargers and turbo-compounding. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [October 7, 2012, 5:15pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/22 "2012-10-07T17:15:58Z")
> [@badger5149](#): > > A stationary engine I would think that might be used to produce electricity could take advantage of a lot of the loses we see in car engine making them far more efficient. It could preheat water to drive a steam engine, eliminating a water pump and fan. It could also use the exhaust for preheating water. Somehow it’s difficult for some people to understand the laws of thermodynamics. Sure, if you can recover what’s otherwise lost, that’s a good thing. But if you need to add more energy to get back some, it isn’t practical. And adding a lot of weight and complexity to get a marginal improvement isn’t going to excite many engineers. But don’t let me stop you. Go to work in your garage and let’s see what you can do! ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [October 7, 2012, 5:21pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/23 "2012-10-07T17:21:52Z")
> [@](#): > > A stationary engine I would think that might be used to produce electricity could take advantage of a lot of the loses we see in car engine making them far more efficient. It could preheat water to drive a steam engine, eliminating a water pump and fan. It could also use the exhaust for preheating water. for a car, the engine’s coolant is just about the normal boiling point of water at STP. It’s not nearly hot enough to be an effective heat source for a steam engine. for stationary engines, we do see that in combined-cycle power plants, where the exhaust of gas turbines is used as the heat source for steam turbines. ---
**Author:** ![Patch](https://avatars.discourse-cdn.com/v4/letter/p/a183cd/32.png) [@Patch](https://boards.straightdope.com/u/Patch)\ **Post date:** [October 7, 2012, 5:27pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/24 "2012-10-07T17:27:27Z")
> [@Sigene](#): > > Well there’s this > [http://www.wired.com/autopia/2010/06/downwind-faster-than-the-wind/](http://www.wired.com/autopia/2010/06/downwind-faster-than-the-wind/) > > wind powered car that goes faster then the wind powering it. It seems to break some fundamental physics laws, but apparently not…since it does actually work. Yeah, but you’ll never get that through the McDonald’s drive-thru. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [October 7, 2012, 5:42pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/25 "2012-10-07T17:42:36Z")
> [@Musicat](#): > > Somehow it’s difficult for some people to understand the laws of thermodynamics. Sure, if you can recover what’s otherwise lost, that’s a good thing. But if you need to add more energy to get back some, it isn’t practical. And adding a lot of weight and complexity to get a marginal improvement isn’t going to excite many engineers. > > But don’t let me stop you. Go to work in your garage and let’s see what you can do! Why would adding weight to a stationary engine require more energy input if the exhaust was simply used to preheat water for a steam turbine? I am in full agreement that adding contraptions to a moving vehicle would arrive at a net loss of power. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [October 7, 2012, 5:56pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/26 "2012-10-07T17:56:41Z")
> [@badger5149](#): > > Why would adding weight to a stationary engine require more energy input if the exhaust was simply used to preheat water for a steam turbine? I am in full agreement that adding contraptions to a moving vehicle would arrive at a net loss of power. Well, then, we are in agreement, aren’t we? What good would a net loss of power be? I can see it now, the ads…“Be the first in your neighborhood to buy our Super Turbo Quantum Energy Recovery Box! Only 30% net loss!” ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [October 7, 2012, 6:11pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/27 "2012-10-07T18:11:23Z")
I, for one, would love to hear what the OP’s insights are on the old [airplane on a treadmill](http://boards.straightdope.com/sdmb/showthread.php?t=465003)issue. We might just get this solved once and for all! 😉 ---
**Author:** ![CableCutter](https://avatars.discourse-cdn.com/v4/letter/c/35a633/32.png) [@CableCutter](https://boards.straightdope.com/u/CableCutter)\ **Post date:** [October 7, 2012, 8:09pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/28 "2012-10-07T20:09:41Z")
> [@Sigene](#): > > [http://www.wired.com/autopia/2010/06/downwind-faster-than-the-wind/](http://www.wired.com/autopia/2010/06/downwind-faster-than-the-wind/) > [@fumster](#): > > How does that work? [![](https://img.youtube.com/vi/FqJOVHHf6mQ/hqdefault.jpg "Directly Down & Up Wind Faster than the Wind") ](https://www.youtube.com/watch?v=FqJOVHHf6mQ) > [@Sigene](#): > > It looks like it’s the opposite of the OP’s example in that it is going down wind. Yes, but you can go directly upwind faster than the wind too. In both cases you need wind relative to the ground, as an energy source. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 7, 2012, 9:04pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/29 "2012-10-07T21:04:53Z")
> [@CableCutter](#): > > Yes, but you can go directly upwind faster than the wind too. In both cases you need wind relative to the ground, as an energy source. The thing that trips a lot of people up with DDFTTW vehicle (and others like it) is that conservation of energy doesn’t mean _conservation of velocity_. ---
**Author:** ![spifflog](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@spifflog](https://boards.straightdope.com/u/spifflog)\ **Post date:** [October 7, 2012, 9:14pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/30 "2012-10-07T21:14:29Z")
> [@voltaire](#): > > I, for one, would love to hear what the OP’s insights are on the old [airplane on a treadmill](http://boards.straightdope.com/sdmb/showthread.php?t=465003)issue. We might just get this solved once and for all! 😉 Ohh no you didn’t :smack::smack: ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 8, 2012, 7:43am UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/31 "2012-10-08T07:43:43Z")
> [@supery00n](#): > > Noooo!! That’s not my point! I was suggesting the following: WTF? I can’t believe you went to all that trouble to (apparently) ignore the fact that (assuming there’s no cross/head/tailwind) _any work you can harvest from a car-mounted wind turbine **is being done by the car** _. ---
**Author:** ![The\_Librarian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_librarian/32/402_2.png) [@The\_Librarian](https://boards.straightdope.com/u/The_Librarian)\ **Post date:** [October 8, 2012, 8:00am UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/32 "2012-10-08T08:00:03Z")
> [@voltaire](#): > > I, for one, would love to hear what the OP’s insights are on the old [airplane on a treadmill](http://boards.straightdope.com/sdmb/showthread.php?t=465003)issue. We might just get this solved once and for all! 😉 Windmills on an airplane on a treadmill. (once, in Rio for twenty minutes a 50’s style goat wasn’t in a wheelchair) ---
**Author:** ![hibernicus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hibernicus/32/2802_2.png) [@hibernicus](https://boards.straightdope.com/u/hibernicus)\ **Post date:** [October 8, 2012, 8:56am UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/33 "2012-10-08T08:56:15Z")
> [@badger5149](#): > > Why would adding weight to a stationary engine require more energy input if the exhaust was simply used to preheat water for a steam turbine? That’s a perfectly reasonable suggestion, from an energy point of view. Heat is often recovered from stationary engines (from the cooling water, the oil and the exhaust) and used for various purposes. If there happened to be a steam turbine conveniently nearby, you could certainly dump the heat from the engine into the bottom of the steam cycle. From an economic point of view, it could well be worthwhile. I am familiar with a power station that consists of 2 x 40 MW diesel engines, run in simple cycle. That’s dumping over 80 MW of heat to atmosphere, which would displace a hell of a lot of fuel in a steam cycle. ---
**Author:** ![CableCutter](https://avatars.discourse-cdn.com/v4/letter/c/35a633/32.png) [@CableCutter](https://boards.straightdope.com/u/CableCutter)\ **Post date:** [October 8, 2012, 10:04am UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/34 "2012-10-08T10:04:29Z")
> [@Mangetout](#): > > WTF? I can’t believe you went to all that trouble to (apparently) ignore the fact that (assuming there’s no cross/head/tailwind) _any work you can harvest from a car-mounted wind turbine **is being done by the car** _. I can’t believe he failed to cite prior art: [http://www.memecenter.com/fun/241597/troll-physics](http://www.memecenter.com/fun/241597/troll-physics) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 8, 2012, 12:06pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/35 "2012-10-08T12:06:25Z")
> [@hibernicus](#): > > That’s a perfectly reasonable suggestion, from an energy point of view. Heat is often recovered from stationary engines (from the cooling water, the oil and the exhaust) and used for various purposes. If there happened to be a steam turbine conveniently nearby, you could certainly dump the heat from the engine into the bottom of the steam cycle. > > From an economic point of view, it could well be worthwhile. I am familiar with a power station that consists of 2 x 40 MW diesel engines, run in simple cycle. That’s dumping over 80 MW of heat to atmosphere, which would displace a hell of a lot of fuel in a steam cycle. Indeed - the notion that _you can’t get more out of a system than we currently do_ is a sloppy assumption - and not equivalent with the fact that _you can’t get out more than you put in_. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 8, 2012, 12:32pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/36 "2012-10-08T12:32:33Z")
On the hopeful assumption that the OP is in some way serious, but just struggling with the math… Forget the wind turbine for a moment. Install a fifth road wheel, trailing behind the car, and have this fifth wheel drive a generator. Is there any way that generator can produce enough power to run the vehicle sustainably? Obviously not. And the wind turbine idea is the same, with the exception that there are greater losses involved in extracting energy from moving air than there are with a mechanical coupling such as the above-mentioned fifth roadwheel. ---
**Author:** ![CableCutter](https://avatars.discourse-cdn.com/v4/letter/c/35a633/32.png) [@CableCutter](https://boards.straightdope.com/u/CableCutter)\ **Post date:** [October 8, 2012, 1:07pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/37 "2012-10-08T13:07:51Z")
> [@Mangetout](#): > > Install a fifth road wheel, trailing behind the car, and have this fifth wheel drive a generator. Is there any way that generator can produce enough power to run the vehicle sustainably? Obviously not. Obviously not… unless the generator wheel runs on a different surface than the engine wheels, and there is a velocity difference between the two surfaces: [![](https://img.youtube.com/vi/pw_B2MnMqZs/hqdefault.jpg "Walkway Carts") ](https://www.youtube.com/watch?v=pw_B2MnMqZs) ---
**Author:** ![Aquadementia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aquadementia/32/555_2.png) [@Aquadementia](https://boards.straightdope.com/u/Aquadementia)\ **Post date:** [October 8, 2012, 2:09pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/38 "2012-10-08T14:09:09Z")
And bumblebees can’t fly. [It’s a wonder this never caught on.](http://www.google.com/patents/US4179007?printsec=drawing&dq=4179007&ei=RN5yUP7LKdLU0gGq6IFA#v=onepage&q&f=false) ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [October 8, 2012, 4:36pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/39 "2012-10-08T16:36:37Z")
Regarding Blackbird, the wind powered car that runs directly downwind faster than the wind that is powering it: > [@fumster](#): > > How does that work? It looks like it’s the opposite of the OP’s example in that it is going down wind. My best guess is that there is more energy available from the wind hitting the surface of the blades then is necessary to propel the car at wind speed, and some of that is being used to turn the wheels. Combine that with the reduced drag from going downwind. Still seems counter intuitive though. > > Not that they are not “sailing” by tacking into the wind. The prop is “sailing” along a downwind beat. Just that is not constrained to a water surface, so it is moving in a continuous helix, rather than doing a series of jibes to zig-zag. The usual objection is that the car is outrunning it’s power source. It is in fact continuously catching up to it’s power source. It grabs the moving air from in front of the prop, and slows it down (relative to the ground) extracting kinetic energy from that air in the process. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 8, 2012, 6:07pm UTC](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757/40 "2012-10-08T18:07:18Z")
> [@CableCutter](#): > > Obviously not… unless the generator wheel runs on a different surface than the engine wheels, and there is a velocity difference between the two surfaces: > [http://www.youtube.com/watch?v=pw\_B2MnMqZs](http://www.youtube.com/watch?v=pw_B2MnMqZs) Quite - and that’s a good demonstration of the basic principle behind the Blackbird DDFTTW machine, however, it’s my impression that the OP is talking about a car driving in a wind-less environment, and somehow extracting useful work from its own forward motion through the air. [Previous page](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757.md?page=1) [Next page](https://boards.straightdope.com/t/attaching-a-wind-turbine-to-an-automobile/636757.md?page=3)