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Old July 19th 05, 03:17 PM
FanJet
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N8N wrote:
> FanJet wrote:
>> N8N wrote:
>>> FanJet wrote:
>>>> Jonathan Race wrote:
>>>>> Many of the new generation hybrids aren't specifically designed to
>>>>> increase fuel economy more than a few MPG but rather to reduce
>>>>> emissions. Since the most emissions are generated in slow speed
>>>>> stop-and-go driving, the use of an electric motor for that type of
>>>>> movement reduces emissions on these vehicles to somewhere between
>>>>> 1/2 and 1/3 of the amount a non-hybrid version of the same vehicle
>>>>> produces.
>>>>> Cheers - Jonathan
>>>>>
>>>>> "Nomen Nescio" > wrote in message
>>>>> ...
>>>>>> What a ripoff to we taxpayers who pay extra taxes so tax
>>>>>> giveaways are given to rich people who buy expensive hybrids
>>>>>> that actually guzzle more gasoline than regular cars you and I
>>>>>> are destined to purchase! Write your Congressperson today and
>>>>>> tell her/him just how you feel about getting the shaft without
>>>>>> the benefit of K-Y Jelly. If a hybrid doesn't get at least 15%
>>>>>> better gas economy, than it
>>>>>> does with its battery removed, tax it double for extra damage it
>>>>>> does to the economy and Nation by using a lot of
>>>>>> contaminating elements in it's battery pak.
>>>>
>>>> Lemee see, there's only *one* source of energy for these vehicles.
>>>> Anyone surprised at the real outcome? BTW, one doesn't run around
>>>> town on electric power for long before the gasoline engine is
>>>> needed to charge the batteries that are powering the electric
>>>> motor. There ain't no free lunch.
>>>
>>> Well, if the hybrid uses regenerative braking, it's entirely
>>> possible that it will get better economy in stop and go driving.
>>>
>>> nate

>>
>> How's that? To use regenerative braking, the car needs to be moving.
>> Gasoline is required to get the car moving either from a gasoline
>> charged battery or directly from the gasoline powered engine. There
>> are considerable losses involved in converting gasoline to
>> electricity and the reverse. If the manufacturers really are saving
>> energy with Hybrids, they could do exactly the same thing with
>> gasoline only powered vehicles. In fact, they should be able to do
>> better since these vehicles wouldn't be carting extra batteries, a
>> heavy electric motor and assorted control doodads around. I think
>> Hybrids buyers are being had. On the other hand, they are probably
>> funding some research that may prove useful in the future so it
>> might not be all bad.

>
> It's real simple. In a gasoline powered car the energy used to
> accelerate a vehicle to whatever speed it achieves is basically lost
> forever, as when the vehicle coasts down or brakes the kinetic energy
> is converted into heat. With regenerative braking, some of it
> (theoretically all, but minus various losses and inefficiencies) gets
> converted back into electricity and stored in the batteries. Not a
> perfect system, but better efficiency-wise than a pure gasoline
> engine. In fact, it's city driving where hybrids can really shine.
> In steady state highway driving, it's a wash, with a slight advantage
> to the pure gasmotor due to lighter weight.
>
> nate


It's not really all that simple and that is the basis for my gripe with the
manufacturers. For example, you ignore the inefficiencies involved with
converting the DC derived from the batteries to the AC required by the
electric motor. Then additional inefficiencies when the AC is converted to
mechanical energy by the electric motor. These inefficiencies generate heat
which is wasted. Then there's the viable possibility of using a less
expensive version of regenerative braking on a gasoline engine only powered
car. Equipped with an ECU controlled alternator clutch, regenerative braking
could be used to charge the car's battery. Using relatively simple
technology, heat from the brakes could be used to assist in heating the
passenger space too. There are many possibilities and some far less
expensive than those used by current hybrids. However you look at it, none
are as simplistic, clean, or effective as the manufacturers would have us
believe.





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