Random idea for a hybrid car.

[SketchMaster]

With GM's new Volt getting a $40,000 price tag slapped on it, it seems less likely that I will ever get to own an electric car. I think the problem is we are trying to make a silver bullet but the technology is not available yet (or not affordable). I came up with a random idea that has pretty much been done already, but never marketed, that would be a good stop gap until we get more cost effective technology out. I'm sure it's full of holes since I'm just applying my basic knowledge of electricity and such to it, so I'm just throwing the idea out there to see if it has any merit.

Take a small light car like the Mini or your favorite Toyota, rip out the large engine and replace it with a small (around 1L) Gas/diesel engine to power a generator, wire the generator to some large capacitors that will store enough power to feed the electric motor if you floor the accelerator pedal while the gas engine revs up to deliver more RPMs to the generator to keep power up and then have either a standard electric motor or those new in wheel motors drive the car. The capacitors will be lighter than batteries and cheaper, the trade off is you you are still burring gas to power the car but less of it (unless I'm wrong and just came up with a more complicated way to burn gas).

So basically:

Small gas egine spins generator to make electricity ---> electricity is sent to a small bank of capacitors to keep enough power stored to smooth out the flow of electricity ----> electricity is then sent to electric motor -----> electric motor is conected to the transmission and powers the wheels.

I'm betting that would get high enough MPG to attract buyers, give good 0-60 times, be cheap enough to build that it could be sold for well under $30k (depending on the frame it's built on) and get people turned onto the idea of electric cars while we figure out how to make a full electric car that everyone can afford.

So, does this idea sink or float?

 

[desy]

http://www.nextenergynews.com/...-energy-news1.25b.html

You mean something like this?

 

[SketchMaster]

Originally posted by: desy
http://www.nextenergynews.com/...-energy-news1.25b.html

You mean something like this?

No, that is a full electric car. My idea is you basicly have a power plant IN your car, you still have to burn gas to power the electric motor.

Like I said, my idea gets rid of batteries and just use enough capacitors to keep a good flow of power to the EM while the ICE revs up to meet power demand.

 

[desy]

http://www.supercars.net/cars/1802.html

Oh you mean this car

 

[SketchMaster]

Originally posted by: desy
http://www.supercars.net/cars/1802.html

Oh you mean this car

Once again, no. That car just uses a very small frame and engine combo to get good MPG and the capacitor is just there to power the lights and A/C to keep the load off the engine.

Let me make this as simple as I can:

Small gas egine spins generator to make electricity ---> electricity is sent to a small bank of capacitors to keep enough power stored to smooth out the flow of electricity ----> electricity is then sent to electric motor -----> electric motor is conected to the transmission and powers the wheels.

 

[desy]

OK
I think Toyota thought about it and the car they came up with was the ES3 since its incorporating every component your envisioning but using it in a slightly different way.
I'd put my money on what Toyota is doing

 

[helpme]

I guess it comes down to which is more efficient. Running a car with a 1L engine, or using that 1L engine to generate electricity, which will then power an electric motor.

(ICE losses + drivetrain losses VS ICE + generation + electric motor + drivetrain losses)

I suppose this might be one of the reasons why hybrids today use both the ICE and electric motors for moving the car. The manufactures have worked out the efficiency curves to see which motor will be better at certain speeds and RPMs.

 

[Uhtrinity]

Originally posted by: helpme
I guess it comes down to which is more efficient. Running a car with a 1L engine, or using that 1L engine to generate electricity, which will then power an electric motor.

(ICE losses + drivetrain losses VS ICE + generation + electric motor + drivetrain losses)

I suppose this might be one of the reasons why hybrids today use both the ICE and electric motors for moving the car. The manufactures have worked out the efficiency curves to see which motor will be better at certain speeds and RPMs.

A gas generator will never be as efficient as grid charging, but does make sense as a range extender.

Also, as far as the ev / ICE in hybrids, it is more a limitation in onboard storage as the EV mode will always be more efficient. This summer I am hoping to add a sizable booster pack to my Insight to boost my in town mpg into the low 100's. It isn't possible with the stock battery as it is too small. This also requires a custom computer system which I have already installed. It allows the driver to change the EV / ICE mix and aggression, as well as being able to completely shut off the EV function.

 

[SketchMaster]

Originally posted by: Uhtrinity

Originally posted by: helpme
I guess it comes down to which is more efficient. Running a car with a 1L engine, or using that 1L engine to generate electricity, which will then power an electric motor.

(ICE losses + drivetrain losses VS ICE + generation + electric motor + drivetrain losses)

I suppose this might be one of the reasons why hybrids today use both the ICE and electric motors for moving the car. The manufactures have worked out the efficiency curves to see which motor will be better at certain speeds and RPMs.

A gas generator will never be as efficient as grid charging, but does make sense as a range extender.

Indeed, but this idea is just to get something out there while we get the kinks worked out of full electric cars.

Really what my question comes down to is, can a gas driven generator provide enough power to an electric motor that will move a small car?

 

[desy]

Of course it can
Trains are diesel electric , the electric motors have the torque to get the train moving and the diesels crank out the power

 

[SketchMaster]

So then the next question is, would my idea be more efficient than current hybrid systems?

 

[Uhtrinity]

Originally posted by: SketchMaster

Originally posted by: Uhtrinity

Originally posted by: helpme
I guess it comes down to which is more efficient. Running a car with a 1L engine, or using that 1L engine to generate electricity, which will then power an electric motor.

(ICE losses + drivetrain losses VS ICE + generation + electric motor + drivetrain losses)

I suppose this might be one of the reasons why hybrids today use both the ICE and electric motors for moving the car. The manufactures have worked out the efficiency curves to see which motor will be better at certain speeds and RPMs.

A gas generator will never be as efficient as grid charging, but does make sense as a range extender.

Indeed, but this idea is just to get something out there while we get the kinks worked out of full electric cars.

Really what my question comes down to is, can a gas driven generator provide enough power to an electric motor that will move a small car?

Supposedly it works in the Chevy Volt, but only nets 40mpg when in ICE generator mode.

 

[Uhtrinity]

Originally posted by: SketchMaster
So then the next question is, would my idea be more efficient than current hybrid systems?

I doubt it, as I mentioned with the Volt, it is supposed to do about 40mpg in ICE generator mode, vs 140mpg from plugin charged (using no gas). I think the conversion losses would defeat the purpose for 100% operation. For a range extender maybe.

Your idea would also require your generator to dump some serious amperage to keep the capacitors full enough, or else you would only have bursts of performance. My Insight can pull up to 100 amps @ 144v dc in comparison most wall outlets are on 15 amps breakers @ 120 volts ac. The system can also do a max charge of 50A @ 144v's when using regenerative braking. Maybe if you used those capacitors for intermediate storage, then dumped the excess into a battery, but the charging system would be complex. When capacitors drain they move somewhat linearly from 0 - full. Batteries on the other hand have a plateau with a sharp fall before empty, and a rise before full. To extend life batteries need to be kept within that plateau. That is why cell phone and laptop batteries have short lifespans.

Some things I can tell you about the Insight, the hybrid portion isn't there for economy, it compensates the anemic performance of the 3 Cylinder 1 liter engine. With EV fully assisting it brings performance into the 1.5 liter ballpark. All of the economy comes from the ICE. The electric motor is also in series with the ICE and cannot be disconnected. It is either passive, assisting, or regenerating. With my car 100% stock I have had drives where I did 60 mph and pulled 90mpg+ for extended distances. Keep in mind this is all ICE performance with very little use of electric assist. The pros who do competitions can pull off 120 - 130 mpg on long courses.

The Prius on the other hand uses a 1.4 or 1.5 Liter high efficiency 4 cylinder engine, as well as an electric motor in parallel. The planetary gearbox can allow the car to run off the ICE, the electric motor, or a mix of the two. The car can also travel about 8 - 10 miles on electricity alone as long as the speed is under 35mph or so. I know 2 families who own Priuses and they average in the mid 50 mpg range, with peaks into the mid 60's.

In both of these cars the batteries have to be recharged using the ICE (which incurs a mpg hit) or regenerative braking unless modifications are made . People have done booster packs in both cars in combination with other mods including plug in wall charging.

Like I mentioned in another thread I want to add a booster pack to my Insight to boost my in town stop and go mileage into the low 100 mpg range vs the 50 - 65 mpg I get now. But in order to do it I will have to use wall charging and it won't be as efficient as a true 100% EV.

Here is a link to the Insight only mod I already installed:

MIMA
Theory of operation for MIMA

 

[MovingTarget]

I have often though of this as well. With the right supercapacitor technology, couldn't you produce and Insight-type vehicle for much less? Considering how much the batteries cost compared to capacitors, you'd think there would be a decent demand for this.

 

[Uhtrinity]

Originally posted by: MovingTarget
I have often though of this as well. With the right supercapacitor technology, couldn't you produce and Insight-type vehicle for much less? Considering how much the batteries cost compared to capacitors, you'd think there would be a decent demand for this.

One of the Insight prototypes uses capacitors. I think the idea was dropped due to the complexity of the DC to DC converters, as the electric motor needs a regulated power source. While capacitors are good at taking or dumping a charge fast, they can't store that charge as long as a battery. I also think storage density is lower, please correct me if I am wrong.

 

[SketchMaster]

I talked to my brother about this last night (much wiser than I when it comes to stuff like this) and basically it's the same idea as a hybrid car but less efficient, too much parasitic loss, ICEs are better for highway and so on.

Oh well, it was fun playing around with the idea.