Warming Predictions

[CalG]

The nice thing about any change, we really have no clue if the result will be better for man kind or not better. It could just be "different".

We keep encouraging our children to "make a difference", "embrace change" etc, But many people seem to be all wound up and troubled when the power goes out.

Life isn't easy every day, but it's not that hard either.

Live responsibly!

 

[Egon]

#1 - I saw a Prius the other day. It was stopped off the side of the road. It's driver was walking away from it with a gas can in hand. Think about that for a second if you have to. A hybrid vehicle out of gas and electricity at the same time and it apparently happens so often that the driver carries a gas can?!?! I would have given him a ride to the station but he probably would have gotten mad at all the laughing I was doing.

So, you have seen a Prius! Interesting that for such a car you even recognized it!

Seems one can see often see cars on the side of the road; even ones that are not Prius!

 

[oldpilgrim]

I wonder...if all cars were electric, could we ever produce enough electricity to charge them.

I doubt it. Even if we could, how much fuel would it take to do it?

Electricity is a very inefficient use of fuel with all the losses it encounters every time it is changed to something else.


assuming we have the fuel and don't take creation of fuel into consideration:

using electricity to power a car:

fuel burns...one loss of energy.
creates steam.. one loss of energy
steam turns turbine... one loss of energy
turbine creates electricity....one loss of energy
electricity moves over wires....one loss of energy.....actually many losses due to resistance and switching
electricity changed to DC in car battery charger....one loss of energy
electricity turns car motor.....one loss of energy


using fuel directly in car:

fuel burns...one loss of energy
fuel turns car motor...one lost of energy

The green weenies just don't get it.

 

[95XL883]

So, you have seen a Prius! Interesting that for such a car you even recognized it!

Seems one can see often see cars on the side of the road; even ones that are not Prius!

Of course I recognized it. I'm a bit of a car guy. You do have to admit that a lot of the hybrid vehicles wouldn't be sold if it wasn't for the huge tax credits.

I did/do feel bad laughing at the situation. I don't wish a roadside failure on anybody. But it does raise an interesting point. If one has an all-electric vehicle (Isn't the Volt all electric?), how does one get it going if you run it entirely out of fuel? Are we going to have to have gas powered generators to be able to charge a stranded electric vehicle?

 

[KennyG]

I wonder...if all cars were electric, could we ever produce enough electricity to charge them.

I doubt it. Even if we could, how much fuel would it take to do it?

Electricity is a very inefficient use of fuel with all the losses it encounters every time it is changed to something else.

This isn't quite as impractical as you assume. I don't foresee an all electric car scenario anytime soon, but the total energy use in the transportation sector is only a little over half of the current electrical energy use. By increasing the number of power plants by 50% we could at least switch all passenger cars to electric. There is a potential silver lining in this also as most charging could probably done off-peak, at night, allowing more of the power plants to be base load and minimizing the stress on the electric grid (distribution system).

The efficiency impact of electric cars is pretty complex. Gasoline engines are limited to thermal efficiencies in the 30 to 35% range, as I recall and there is no mechanism for regeneration (capturing braking energy). On the other hand, electric motors can easily be 95% efficient and allow regeneration. On the electric generation side, coal plants typically have over 40% thermal efficiency and combined cycle gas plants can exceed 60% thermal efficiency. Losses in transmission are generally less than 10%. I don't know what the charge/discharge efficiency of the advanced batteries would be now. If the electricity is generated by wind, solar, nuclear or hydro, the efficiency probably isn't something to be considered, only cost.

The modern internal combustion engine is a marvel, but there are efficiency limitations in the Otto cycle (and it's offshoots) that will keep it's efficiency well below a central station power plant.

 

[Egon]

Of course I recognized it. I'm a bit of a car guy. You do have to admit that a lot of the hybrid vehicles wouldn't be sold if it wasn't for the huge tax credits.

I did/do feel bad laughing at the situation. I don't wish a roadside failure on anybody. But it does raise an interesting point. If one has an all-electric vehicle (Isn't the Volt all electric?), how does one get it going if you run it entirely out of fuel? Are we going to have to have gas powered generators to be able to charge a stranded electric vehicle?

I do not know what the remedial action would be but it may be similar to what happens to a conventional vehicle which has stopped running while being driven on the road.

As an aside do regular vehicles ever run out of fuel while on the road??

 

[bcp]

You walk to the nearest outlet and get a can of electricity.



Bruce

 

[Egon]

I wonder...if all cars were electric, could we ever produce enough electricity to charge them.

I doubt it. Even if we could, how much fuel would it take to do it?

Electricity is a very inefficient use of fuel with all the losses it encounters every time it is changed to something else.


assuming we have the fuel and don't take creation of fuel into consideration:

using electricity to power a car:

fuel burns...one loss of energy.
creates steam.. one loss of energy
steam turns turbine... one loss of energy
turbine creates electricity....one loss of energy
electricity moves over wires....one loss of energy.....actually many losses due to resistance and switching
electricity changed to DC in car battery charger....one loss of energy
electricity turns car motor.....one loss of energy


using fuel directly in car:

fuel burns...one loss of energy
fuel turns car motor...one lost of energy

The green weenies just don't get it.

Sun shines electricity produced stored in battery one loss of energy conversion.

Now the gasoline fuel you talk about start the energy losses at the beginning. See how that works.

 

[Egon]

You walk to the nearest outlet and get a can of electricity.



Bruce

That could be one way but it might be called a charged back up battery as easily as a can.

 

[houstonscott]

Of course I recognized it. I'm a bit of a car guy. You do have to admit that a lot of the hybrid vehicles wouldn't be sold if it wasn't for the huge tax credits. I did/do feel bad laughing at the situation. I don't wish a roadside failure on anybody. But it does raise an interesting point. If one has an all-electric vehicle (Isn't the Volt all electric?), how does one get it going if you run it entirely out of fuel? Are we going to have to have gas powered generators to be able to charge a stranded electric vehicle?

The idea of renewable becomes comical as you walk toward a gas station, even funnier if on a calm night. HS