"However as Tim K says.... all the energy comes from the engine at some point. Even the regeneration. The car USED energy to get moving... regen just recaptures the energy that WOULD have been wasted as heat when you applied the brakes in a normal car. But that energy came from gasoline one way or another unless the vehicle is always driving downhill "

Not totally true. There are times when I can get my car into coast that regenerates energy. Granted, the regeneration of coast in ICE mode is from the gas engine. But, this will power my car later when it is in EV only mode, whereas a gas engine can't capture this (wasted energy now saved.) However, where does the energy for regeneration come from when my car is in EV mode and the battery is charging? (at many stoplights, as well as in L mode on hills.)

 

Sorry.... this thread is getting a little off topic.

I'm not trying to be nasty here...just trying to explain. You misunderstand how hybrids work. Transfering energy from mechainical to electrical is not a gain of energy... its a loss. And its not more effiecient inherently its just better at moving a car at low speed. As a matter of fact GM just demonstrated a hybrid trasmission that saves an additional 25% of energy over the kind in our car..... by..... shutting off the electric motor at *HIGH* speeds and driving the wheels directly from the engine!!! I kid you not, I read it a week ago (if found the 25% number amazing considering how good the mileage is on a Prius--shows how far there is to go optmizing these things).

A hybrid is efficient because of a simple thing. Electrical motors are really good at moving vehicles at low speeds, but very poor at high speeds. Gasoline motors are good at high speed but bad low speed. By merging the two you have an system that can run in the most efficient mode whenever it needs too.

You actually don't need a V6 to push a car down the road at 60mph... you need a V6 to get the thing moving in the first place because an ICE has poor low end torque. When its at full speed an engine is bascially oversized for the job because it needs to be very large to get rolling. This is inefficient.

Hybrids don't gain any energy advantage by converting ICE energy to electricy and back to motion... They are efficient because of two main reasons. You can put a smaller lighter engine in and supplement it with the electic at low speed (where the electric is better). As a bonus you can recapture some of the energy you used accelerating the vehicle when you stop it. Normal cars just dissappate and lose that energy as heat in the brakes, hybrids recapture it in a battery by regenerative braking and then release it the next time you accelerate. They don't recapture all of it becuase of losses... but they do better than just loosing it all to heat.

There is not inherent advantage to converting energy to electricity to drive a car, except at low speed. There is still energy lost in the conversion, but the gain of a lightweight motor at high speed (and a more fuel efficient one at high speed) coupled with a better transmission that has the optimal "gear" ratio at all speeds means the hybrid gains.

However.... if you are driving the car along and running an A/C compressor.... The ICE can turn the compressor through a belt with only a few percent loss throught the clutch (talked to my brother.. a mechanical engineer in the car industry). Generators loose more energy than that.. and then you'd loose some more getting back in the electric motor on the compressor.

So its true that its more efficient at moderate speeds to drive the A/C off the engine. When its sitting still its better to run it from electric because an idling engine is pretty darn ineffient. HOWEVER what is happening MOST of the time... most of the time the engine is running to drive the car anyway.

I'm an EE. There are many examples where things are counter intuitive. For example, you can make a part of a program run 10% faster and another part run only 1% faster. The first seems better... but if the first one only runs 1% of the time and the second part runs 99% of the time you'd do better to do the second one... not the first.

 

At some point the energy in your battery came from gasoline and the ICE. When you are using EV mode you are just expending that energy that was stored from the ICE. When you regen in EV mode you are just recapturing some of the energy you just used to get rolling in EV mode that would have gone to the brakes. But all the energy in that battery came from gasoline and the ICE at some POINT!

Don't beleive me.... Drive around the block a few times really slow in EV mode.... when you get back to the starting point you'll find your battery charge is lower (unless the engine kicked on to recharge it). The regen didn't gain you any energy!!! it can't. It would violate the laws of physics. A car without regen would drain the battery even faster because there would be no recapture of brake losses, but you don't get more back then the energy expended making the car move in the first place. By thermodynamics you have to get back less!!!

This is a secondary battery..... it doesn't produce energy. It stores it. Its that simple. Until you plug the thing into the wall ALL the energy driving that car came from the ICE and gasoline. When you are in EV mode you aren't getting any free energy. You are just using the energy produced by the ICE that would have been lost in the brakes (or you are using energy put there during charging when the hybrid started--this is done so the battery never gets too low)

 

By the way... hope no one things I'm trying to start an argument, or put anyone down. Its a forum. We are all trying to learn things--I've learned alot on here. I'm just trying to explain how the system works. Not "jump" on anyone or "prove them wrong".

 

Why, or how, are all high speed railroads electric?

 

Because getting a huge long train moving... Requires a HUGE amount of low end torque.

 

Thats also why most freight trains are diesel-electric.

 

I'm obviously NOT very good at explaining this.

Have a look at http://auto.howstuffworks.com/hybrid-car.htm and see if that helps. On the page that talks about Honda Insight about halfway down you'll find:

"But the real effectiveness of the electric motor occurs at lower engine speeds. The electric motor on the Insight is rated at 10 kilowatts (about 13 horsepower) at 3,000 rpm.

It's the peak torque numbers that really tell the story. Without the electric motor, the Insight makes its peak torque of 66 pound-feet at 4,800 rpm. With the electric motor, it makes 79 pound-feet at 1,500 rpm. So the motor adds a lot of torque to the low end of the speed range, where the engine is weaker. This is a nice compromise that allows Honda to give a very small engine the feel of a much larger one"

I hope that explains things better than I have... Its a very detailed article!

 

One last comment that is a bit of a back pedal because I over simplified things....

I didn't mean you can't MAKE electric motors that do work well at high speed and I should have said that. But the ones in our vehicles aren't intended for that. They are primarily to add the low end torque a conventional ICE lacks.

Also.... I'll bet (but I don't know) that high speed trains that are generating their own electricity use gas turbines to spin the generators that power the electric motor. This is actually a pretty darn efficient way to make electricity (much better than an engine with pistons which are miserable).... too bad our hybrids didn't use gas turbines . I think Chrysler did a prototype gas turbine car back in the 70's.

 

Teester, you are good at researching stuff online, then speaking intelligently about it. But now matter how hard you tried, you haven't told me anything I don't already know. You're preaching to the quire, my brother. Trust me, as an ASE certified automobile technician and someone who has been factory trained by Ford on the FEH(before it even came out), I know how Ford's hybrid works. You were saying that mechanical to electrical to machanical wasnn't as efficient as just straight mechanical. That would make hybrids obsolete.