Breaking news! Chevy volt technically driven by gas engine!

[rmay635703]

Originally Posted by dcb

because that is logically the most efficient mode, even in parallel operation, and a good driver can take advantage of higher peak efficiency parallel provides. Aren't the efficient turboshaft engines like the size of a room?

Not all, some very small units are in the 40's, they are just much less common than the big boys due to the applications they use them for.

The other way around this of coarse would be a diesel genset but they are all over the map eff. wise as well.

Also, no offense but 50lbs verses 200lbs is a consideration. Also smaller is usually cheaper which is another measure of efficiency.

And a motor that is SMALLER than required could be operated continously at its most efficient peak area regardless of the speeds I drive, If I had a genset that operated peak eff at full speed, it would be recharging my batteries all the time because I rarely travel full blast and have lots of stops. Whereas a motor sized just big enough to toot me along at 25mph would always be operating at its peak efficiency and would improve my range significantly enough that I would never have to worry about it. (I don't drive 200miles one way)

[Rokeby]

FWIW, Jaguar is working on a turbine-electric hybrid to be released in 2013,
the C-X75 concept:



That's the breathtaking Jag coupe that would use a pair of tiny
microturbines to generate electricity to keep the electric wheel-motors
running the grid-charged lithium-ion batteries were depleted.

The one rated at 778 horsepower and, Jaguar engineers say, capable if built
of delivering up to 68 miles of all-electric range before the turbines would
kick in.

Turns out there are still two problems to be overcome before concept could
become reality - how to efficiently and effectively supply the tiny turbine
range extenders with all the air they need without turning the entire car into
a giant scoop, and how to manage the extremely high-temperature exhaust
from the turbines.
Green Car Advisor

Jaguar Land Rover is working on the car with British gas turbine
manufacturer Bladon Jets and electric motor manufacturer SR Drives. The
Technology Strategy Board, which funds business development in the U.K., is
underwriting the first serious attempt at a turbine car since Volvo built the
Hybrid Environmental Concept in 1993. The goal, according to Bladon, is the
“world’s first commercially viable – and environmentally friendly – gas
turbine generator designed specifically for automotive applications.”

Previous attempts at turbine-powered cars, of which the Chrysler Turbine Car
might be the most famous, used the technology to turn the driveshaft. But
the Jag — like the Volvo — would use a miniature gas turbine only to
generate juice for the electric motor. Bladon says its axial flow turbines are
small, lightweight and run on anything from natural gas to biofuel. That, it
says, makes them a great alternative to the conventional engines used in
range-extended hybrids like the Chevrolet Volt.
Wired.com

[rmay635703]

Originally Posted by Rokeby

FWIW, Jaguar is working on a turbine-electric hybrid to be released in 2013,
the C-X75 concept:



That's the breathtaking Jag coupe that would use a pair of tiny
microturbines to generate electricity to keep the electric wheel-motors
running the grid-charged lithium-ion batteries were depleted.

The one rated at 778 horsepower and, Jaguar engineers say, capable if built
of delivering up to 68 miles of all-electric range before the turbines would
kick in.

Turns out there are still two problems to be overcome before concept could
become reality - how to efficiently and effectively supply the tiny turbine
range extenders with all the air they need without turning the entire car into
a giant scoop, and how to manage the extremely high-temperature exhaust
from the turbines.

One solution is to use a smaller set of turbines, the other is that superheated exhaust is not efficient and likely could be used to produce more power.

[Rokeby]

RE: "the extremely high-temperature exhaust from the turbines."

It doesn't seem to be an issue for this street-legal turbine powered hottie:

[MN Driver]

Originally Posted by rmay635703

I cannot understand what everyone fascination with making a range EXTENDER into a steady state driving apparatus. My feel is that the genset should never be large enough to run the car. I want to extend my range in certain circumstances, not make it unlimited. Even if the genset can only output 1/3 of the power I need that increases the distance I can drive by 33% (50miles wan't uncommon for me,another third is 66miles) if I have a charge controller to maintain constant output (no overload)
Also a genset that can output a fraction of what is needed to run the car will still recharge the batteries when I am coasting, at stop signs or potentially in a parking lot, meaning I still likely can travel a good ways if required. Also a smaller genset is lighter and not going to significantly impact my range in of itself.

And in my case my car is 1200lbs and can't go faster than 55mph anyway, so the amount of power I would need is significantly less.

Cheers
Ryan

You might need to reread or reconsider my post. I was discussing highway travel, figuring that I'm not going slower than 60mph, if I could manage a 6500 watts rated genset to power me on the highway at that speed without depleating my batteries on the way, I want to know what setup would get me 108wh/mile at 60mph or even 130wh/mile at 50mph because that would be the electric car of my dreams. ...if I were to get 200 or less wh/mile at 60mph(this number makes math easier)like I'm sure I would, I'm still depleting the pack at about half the usual rate considering 12kw consumed and 6.5kw going to a charger which will have its own losses. ...so 100 miles, use half of the energy from the battery while half comes from a genset, I'm still likely going to have to stop for a little bit on the way to Madison to let things catch up. ...maybe not a long time but a 6500watt generator would be overkill on side roads but not on the highway. It should provide a good proportion of power, arrive with your pack used and the generator under load. ...maybe past its efficiency point but on a rare trip to show off an electric car, it's not ideal financially unless I already had the generator or was planning to buy it for more than one purpose(I'm actually looking to get the 3000watt one but that wouldn't be big enough for this but bigger than I need for home use to run the furnace and refrigerator), probably cheaper to tow the car than try to set things up to get this to work. More of the principle or hobby nature of it I suppose. I probably wouldn't have the motivation to do it unless a small fortune landed on my lap with a note attached saying to dedicate it to the cause. ...so, theories, thoughts, strange fading dreams that seem to make sense until you've woken up.

[rmay635703]

Originally Posted by MN Driver

You might need to reread or reconsider my post. I was discussing highway travel, figuring that I'm not going slower than 60mph, if I could manage a 6500 watts rated genset to power me on the highway at that speed without depleating my batteries on the way,

I'm still depleting the pack at about half the usual rate considering 12kw consumed and 6.5kw going to a charger which will have its own losses. ...so 100 miles, use half of the energy from the battery while half comes from a genset, I'm still likely going to have to stop for a little bit on the way to Madison to let things catch up. ...maybe not a long time but a 6500watt generator would be overkill on side roads but not on the highway. It should provide a good proportion of power, arrive with your pack used and the generator under load.

If you have a lead acid pack and you cut the power consumed in half you will actually be able to travel 2.5-3 times further (just guestimating but most FLA have a High Peurkert exponent which means the less you draw the more capacity you have to use) That is why a few folks can make a commutacar on a 72v set of 6v trojan 105's drive them 100 miles but only at about 22-25mph, those same folks have trouble with 40 miles going 45mph.

Also Its hard to say at what wattage a given genset makes it most efficiently in the wild so to say without some sort of data sheet. My fathers coleman which can output 1500watt continous definately does not run very efficiently at full output, its good to really about 1200watts and can run much of the day, beyond that and its run time is cut in less than half and sounds like its gonna blow to pieces.

Cheers
Ryan

[NeilBlanchard]

Exclusive Video: Want to Know EXACTLY How the Chevy Volt Powertrain Works? | PluginCars.com

Okay, this gets pretty convoluted -- the genset in mode #3 does charge the battery; but only to maintain the "buffer" state. Look at the second video around 4:50.

[autoteach]

I am not sure who it was, but the worry about the planetary is, or shouldnt be, a worry.
HowStuffWorks "The Planetary Gearset"

[tjts1]

Originally Posted by NeilBlanchard

Exclusive Video: Want to Know EXACTLY How the Chevy Volt Powertrain Works? | PluginCars.com

Okay, this gets pretty convoluted -- the genset in mode #3 does charge the battery; but only to maintain the "buffer" state. Look at the second video around 4:50.

Excellent videos. Thanks for posting that.

[MN Driver]

The first video that I've found yet of an electric car idling.

http://www.youtube.com/watch?v=0YRAlwjf10o

...wait, I thought electric cars don't idle.