Real Energy Strategy for America: Hybrid Cars Stir Passions [Confusion of hybrids vs. electric]

New Media Journal ^ | June 19, 2008 | Jonathon Moseley

[Moseley]

A great many confuse hybrid cars with electric cars plugged in to the wall. Hybrids are a completely different animal. Confusing hybrids with electric cars, many raise objections that apply only to electric cars. Hybrids do not use any electricity from the power grid. They run exclusively on gasoline.

Many people apparently think that “hybrid” means that a hybrid car is simultaneously a purely electric car and also a traditional car, requiring all the mechanisms of both. Comments reflect the incorrect idea that a hybrid switches between running like a normal car to running like an electric. Comments then suggest that maintaining such a complicated car would be expensive.

Actually, a hybrid car is simpler and easier to maintain. Like enormously powerful diesel-electric locomotives, a hybrid uses only an electric drive. There is only one drive system, not two. The wheels are powered either by the gasoline engine generating electricity or by electricity stored in the battery from the gas engine. The engine only runs when more electricity is needed. But the drive system does not care whether the power is coming from the gas engine, from the battery, or both together under a heavy load. Energy is fed to the same, single drive system from two different possible sources (or both together when extra kick is needed).

The fact that the engine is completely turned off at stop lights and when cruising is a fundamental change that saves gasoline. Many questioned how the gas engine in a hybrid can be any more efficient than a traditional gas engine. Simply put, an engine that is not running at all uses less gasoline. The engine kicks off whenever it has stored up enough electricity in the battery. Therefore, the engine is using no gas at all some of the time.

[the invisib1e hand]

[Confusion of hybrids vs. electric]

Sort of like, I don't know, a boxing match between PeeWee Herman and the Dali Lama?

[rhombus]

We can’t hybrid our way out of this mess. ;-)

[Dick Bachert]

I’d guess you’ll need a new STARTER about once a year.

But that’s a small price to pay for saving the earth (from Algore).

[thackney]

a hybrid uses only an electric drive.

Some hybrids, not all, meet this definition. Honda uses the engine to also drive the transmission.

http://automobiles.honda.com/civic-hybrid/features.aspx?Feature=ima

[Malsua]

Actually, a hybrid car is simpler and easier to maintain. Like enormously powerful diesel-electric locomotives, a hybrid uses only an electric drive. There is only one drive system, not two. The wheels are powered either by the gasoline engine generating electricity or by electricity stored in the battery from the gas engine. The engine only runs when more electricity is needed.

You're just wrong on this. No Hybrid on the road today runs in this fashion as parallel hybrids. The Volt will as a SERIES Hybrid. The Prius, Civic, Lexus et. al. run the gas motor to drive the wheels and siphon any extra power off to charge the batteries. The AC motor isn't driving the wheels.

[Moseley]

You need to test drive a hybrid. When the hybrid accelerates from stop at a red light up to 55 MPH — absolutely silent the entire way — you will have a completely different understanding of hybrids. The light turns green. You hit the “gas.” There is enough electricity in the battery, so the gas engine STAYS OFF. With the gas engine TURNED OFF, the car silently accelerates faster than the other cars around you, and zips up to 55 MPH — 100% silent.

The car is run from the electric motor drive train, just like a diesel-electric locomotive.

[Jack of all Trades]

Good presentation of regenerative braking. Poor research on drivetrain fundamentals - The engine also drives the wheels directly in many applications. Poor research and unfounded assumptions on automotive durability and servicability. Electronic solutions are not as robust in automotive environments as mechanical ones. Consider the probability of second sourcing key components, or even service for that matter.

Overall grade: C

[thackney]

Prius sometimes accelerates strictly on the electric drive depending on battery level and other conditions. But it will also use the engine to directly drive transmission in addition to the electric motor.

The diagram below is a schematic of the Prius powertrain:

Toyota Prius Technical Information
http://www.cleangreencar.co.nz/page/prius-technical-info

[The Great RJ]

I was a hybrid skeptic until my wife bought a Mercury Mariner hybrid. Her gas mileage with a comfortable sized SUV is in the high 30 mpg range and is actually better in stop and go city driving than on the highway. Are hybrids the answer to all our energy problems...no, but they are a step in the right direction and are available and practical now where hydrogen power, fuel cells or rechargeable electric vehicles may be years if not decades away.

[Moseley]

thackney WROTE: “Prius sometimes accelerates strictly on the electric drive depending on battery level and other conditions. But it will also use the engine to directly drive transmission in addition to the electric motor.
The diagram below is a schematic of the Prius powertrain:”

ME: Ummm... Did you actually LOOK at the diagram you posted?

The diagram says exactly the opposite.

The diagram shows NO direct connection between the gasoline (petrol) engine and the wheels.

The diagram you posted confirms what I wrote, and disproves what you are saying. The gasoline (petrol) engine generates electricity. The electricity drives the wheels.

Look at your diagram. There is no direct drive between the gas engine and the wheels. There is only one drive train.... electric.

[Bogey78O]

Give it up. I’m arguing with him in another thread. He doesn’t understand how hybrids work.

[Bogey78O]

The diagram is a simplification of the interconecting parts. Follow the link and it’ll explain it. You might learn something.

[Malsua]

I think he doesn't understand what the "power split device" does. No will he read the detail.

The Prius has an internal combustion engine (ICE) which is unusually small for a car of this size (1300 kg). This is made possible by the presence of the electric motors and battery, which supplement the ICE when power demand is high.

Key statement there.

I re-jigged the drawing. Maybe he'll get it.

[thackney]

I re-jigged the drawing.

No, you deleted the connection between the engine and the drive train. The Power Split Device (Toyota's term) delivers power from both the electric motor and the gasoline engine to the drive train.

For an explanation how it works, click below:
http://www.ecrostech.com/prius/original/Understanding/PowerSplitDevice.htm

For further information try reading:

Evaluation of 2004 Toyota Prius
Hybrid Electric Drive System
http://www.osti.gov/energycitations/servlets/purl/890029-WIfqPO/890029.PDF

On page 8 you will find:
The purpose for the power-split device is to allow power from the engine to turn the generator and the wheels simultaneously.

[Malsua]

No, you deleted the connection between the engine and the drive train.

Did you even READ THE TEXT IN THE PICTURE?

[thackney]

Yes.

Try reading the links I posted.

Then perhaps you will understand that the shaft is solid from the engine through the generator/motor to the Power Split Device delivering power from the engine to the drive train.

It can operate with or without the engine running, but with the engine running, it can and will deliver power directly from the engine to the wheels in addition to the motor.

[Malsua]

Yes

Uhm, no you didn't. What part of "NOT a Parallel Hybrid like a Prius" makes you think my re-done drawing has anything to do with a Prius? It doesn't, it's completely unrelated since the Prius is not a series hybrid. I know how a Prius works, see first drawing. Moseley is the one that can't seem to understand that the ICE drives the wheels in tandem with electric motor.

[thackney]

Sorry, I thought you were referring to the original drawing.

You statement is correct, I was off-topic for your post.