someone help me out here,

[madokie]

I keep reading how an electric car is no better than an ICE auto because of all the co2 released in making the electric to recharge the batteries. If the auto is recharged in the night time hours when the demand for electric is low but some demand is still there so the plants are up and running anyway, why wouldn't it be proper to compare the co2 produced for charging the battery with only the amount made in making the extra energy needed only to recharge the batteries rather that comparing it to all the co2 produced even though the largest percent produced is for the power that keeps our homes and businesses operational during those night time hours? call me confused I guess

I have to step out for a bit but I'll be back and I'm interested in your thoughts on this, thanks in advance.

[phantom power]

1. It isn't easy to come up with a well-defined answer to that.

For one thing, it depends on how that electricity was generated. If it was generated by something like hydro or nuclear power, then it would be carbon-free energy charging your car. If it was coal, then it wasn't carbon free. And in reality, everybody's grid is a mix of energy sources, with varying CO2 externalities. However, even if it was something like coal, you benefit from economies of scale: getting that energy was more efficient than refining oil into gasoline, transporting that gasoline to a local gas station, and burning in your not-very-efficient ICE. Then again there are some transmission losses over the grid to consider.

I think the general answer would be that charging the electric is more CO2 efficient than an ICE, but if somebody has math that says otherwise, I wouldn't be surprised.

[GliderGuider]

2. Think of it this way

As a first approximation the mix of generation sources is pretty much the same on and off peak, with the proviso that off-peak capacity may use less fast-response sources like natural gas turbines. The difference is marginal enough that the "average" generating mix can be used to calculate the amount of CO2 generated per kilowatt. If the difference between the CO2 produced by the on peak and off peak capacity is going to make or break the advantage of an electric car, I'd say the situation is too marginal to begin with, and you should really look at improving the grid's generating capacity before you worry about electric cars.

[madokie]

3. what I'm saying is if the power plant is already running because of these other loads

and the capacity of the generator is much larger than what the load is would it be proper to compare the two. Its that less fast-response sources that I'm talking about the ones that are already running. maybe I haven't hit on what it is I'm trying to ask yet, I don't know

[GliderGuider]

4. Every kilowatt-hour you use has to be generated.

There's no "spare" power that's being generated anyway but gets shunted to ground if it's not used, if that helps clarify the idea. There are load-balancing techniques that involve balancing demand between grids as well as some amount of fast-response capacity that's in use at all times, but if you want to put a kilowatt-hour into a battery, it has to be generated.

[madokie]

6. isn't a larger percentage of the energy being used when a power plant is only partially loaded

being used to keep the thing operating, as when it is under max or near max load. I'm not doubting you but there is a big divide between what I'm thinking and what my abilities to convey that thought is

[TreasonousBastard]

5. It depends...

on a lot of things.

In general, though, internal combustion engines are so inefficient that most electrical generation will result in less of a carbon footprint.

And, yes, recharging at night would often tend to increase the efficiency of a power plant that would not be working at full capacity, saving even more carbon. It would also be cheaper in areas where the power company gives "night rates."

on edit...

There are lots of conflicting sources on all this, but fossil fueled plants can get up to close to 60% efficiency in some cases, while a car engine will never get much over 20%. Even transmission losses and other inefficencies won't kill this advantage. Plus, the grid gets its power mainly from fossil fuels, but from other renwable and nonpolluting sources, too, reducing its carbon footprint even more.

There's also lots of engineering stuff about the efficiencies of electric motors and acceleration and things, too, that makes the elctric motor look even better.

[madokie]

7. Ok so what I'm thinking is maybe correct then

we should be comparing it to the extra co2 being made to generate the extra power not to the total of the two.

[TreasonousBastard]

8. Yeah, that too, but reread...

my edited post.

Yes, I would think (without actually knowing the numbers) that the extra kilowatt or so charging car batteries would be almost meaningless in additional CO2 production in a coal plant churning out a few mwegawatts at the time.

[madokie]

9. thats the way I'm seeing it too

I think we're on the same page

[kestrel91316]

10. You also need to consider the SOURCE of electricity.

If it is from renewables in part (pretty much everywhere in the US has some renewables contributing to the grid, right?), then that lowers the CO2 generated. If CNG goes to provide some of the electricity, that's cleaner and more efficient than gasoline power.

Electric cars are not a perfect solution, but they are a step in the right direction. And there's always the possibility of the electricity being from 100% renewables down the road, or in an individual home that's got PV panels and or wind.

Edit: this is just ONE MORE CASE of the naysayers saying that if it's not a 100% total solution, then it must not be used under any circumstances.

Stupid people really piss me off.........

[madokie]

11. I hope I'm not one of them stupid people you mention ;-)

one of the reason we can't or shouldn't have electric vehicles is because of the dirty electric to charge the batteries is one of the first arguments mentioned when a person talks about EV's so I want to discuss that energy and the road it travels to get here to my late at night electrical plugs. in other words I'm trying to learn by asking question that I don't hear being asked. In so asking and listening I am now a little less ignorant on this subject. :hi: