# Add a wind turbine to a car?

1. Jan 18, 2010

### lumberer

I know this question was already asked but I wanted to tackle it from a different angle.

I saw allot of posts on how it would take too much gas to create the energy from the turbine but for the example lets say the car is electric.

Now say we have a system where the turbine is in a tube aerodynamically built into the car, and this tube is opened and closed by pulleys or some such simple system connected to the gas pedals. Oh and the tube closes when the gas pedal is being pushed upon

Okay with all of that we have a turbine that only inflicts drag upon the car when the gas is not in use aka when your coasting down hill or braking.

Could you use this system to increase "gas" mileage? For example converting the Potential energy of gravity into electricity?

Sorry if its a stupid question but i started reading about wind turbines two days ago and this is one of a few ideas that popped into my head, and they haunt me until I get them out.

2. Jan 18, 2010

### Vale-46

The only way I can see you getting a net gain in energy is from either of the following:
1) the wind turbine runs when the car is sitting parked somewhere.
2) the wind turbine has its cover opened to oncoming wind when you want to slow the car down. This will lessen the torque that the brakes need to provide, and save a bit of wear on the tyres, but regen brakes would probably do a more effective job.

3. Jan 18, 2010

### Mech_Engineer

In short, it still won't work.

When you're coasting, your car is "charged up" with kinetic energy, and running a wind turbine will take from that kinetic energy, slowing the car down. You would have to burn more gas to get up to speed again.

For regenerative braking, a turbine large enough to take a significant amount of energy from the car in a reasonable amount of time would be prohibitively large. You're better off using an electric motor as a generator.

4. Jan 18, 2010

### Staff: Mentor

To reiterate, yes, you could, but it would only be useful when the car is braking or coasting in anticipation of the need to slow down. But in that case, regenerative braking would be more efficient.

5. Jan 19, 2010

### Lsos

Yeah you *could* get some energy out that way, but it would probably take more energy to construct this system in the first place. Not to mention the cost.

As was mentioned, a better way would be for example to use a generator. But even then you would need electric motors to be able to make use of this energy. Plus batteries to store it. A hybrid already has all these, and coincidentally they also have generators that regain energy from the wheels.