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Interesting give-and-take re: PHEVs and energy consumption at gristmill.

http://gristmill.grist.org/story/2007/11/18/141257/28

Posted primarily so that I can refer back to it and comments here as needed. :)

Hi Marc:

___Good rebuttal but what neither party mentions is the cost in both GHG emissions and electricity consumption to produce a gallon of gasoline. A gallon of gasoline emits ~ 19.6 #’s from the tank to the tail pipe but it is also responsible for ~ 9 #’s of CO2 from hole to pump. This number is rising quickly as we dig even deeper and in far more remote locations to pump raw and even heavier crude. The 9#’s of CO2 from an electrical power plant (even dirty coal) in and of itself can drive a PHEV some 27 miles which is far more distance than the average car and truck receives on the gallon of gas let alone the extra 19.6 #’s it throws up for every gallon. Gasoline is an energy carrier and nobody seems to get it :angry:

___Good Luck

___Wayne

Marc,

Great finds! (the 1st link responds to another article)

The older of the two article seems to exaggerate the amount of GHGs emitted from a coal-powered plant a PHEV might use - not the best power plant, but still greener than a conventional hybrid.

People forget that electric motors are ~95% efficient, even if the coal burning is ~35% efficient at producing electricity (about a low end according to wikipedia), you still get ~33% well-to-wheel efficiency. That's still a huge improvement over the ~20% mechanical efficiency of ICE. Even if we call the transport of fuel a wash it's a huge win (though I think moving a lot of coal to one place is better than moving lots of gas to hundreds of places). Plus, you have the huge win of more easily sequestering the GHG and smog emissions.

To heck with all this debate! I am now driving one via a mini-me avatar PHEV iCar!!! :-)
I hope you enjoy.

Btw, there is yet another great argument for PHEV. Sherry Boshert brings it up in "Plug in Hybrids". And that is that it makes wind energy truly useable. The problem with wind is that it tends to be highest in off-peak times, the same as when the PHEV would be recharging. Energy companies like things most even and I understand the more even the better.
Quite a few states have significant wind energy possibilities.


--des

I've talked to people about this, people who say "you're just trading one fossil fuel for another, it's exactly the same." I know it's not, but I never get past the first few sentences without them getting bored or annoyed (yeah, they can make a blatantly false statement and expect me to listen, but they can't listen to a civil rebuttal... :angry: arrrrgh!!!).

Is there any quick rebuttal that might actually get people to listen? What do you guys say?

Power plants are more efficent than gasoline motors.

To add to what Blake has posted, they are more efficient because of the sheer mass of the things. Also, because all emissions are coming from one location the "scrubbers" to clean them up are much more efficient -- due in part to the added space available for more effective cleaning methods. A lot of what is done in a power plant simply cannot be shrunk down to work in a car.

So, power production in a plant is more efficient and the emissions are better by far than the collective emissions of gas powered cars.

Oil supports terroism, Coal supports Americans

And solar power supports the future of the earth ;)

I have a co-worker who "knows" that hybrids can't be more efficient because every energy conversion has losses. I've decided that the best way to explain the benefits of hybrids (or PHEVs) is to start by agreeing with them. Such as, "The Prius uses its engine in a rather inefficient manner, and the electrical system also has significant losses. But a normal car uses its engine in an incredibly inefficient manner, and that difference between "incredibly inefficient" and "rather inefficient" is big enough that with good engineering, the hybrid can come out way ahead, even though the hybrid system itself is inefficient. Note that hybridization isn't guaranteed to come out ahead. Any fool can design an inefficient system, or drive a hybrid poorly. That doesn't prove anything."

A quote from an old thread, updated a little:

*****************************************************
http://www.cleanmpg.com/forums/in-the-news/t-in-quest-for-better-battery-keep-an-eye-on-nationalism-4184.html#post25055

There are several reasons why a PHEV using grid power is much less polluting than a gas car, even in areas that are highly dependent on coal for power.

First, don’t assume you’re just replacing the energy content of gas with the same amount of electricity. There's a huge difference. Burning gas to move a car is incredibly wasteful —it’s like burning dollar bills in your fireplace to heat your home. By converting to an electric mode of transportation you gain larger efficiencies from the battery and electric motor.

Pollution control at a power plant is far easier and more efficient than in a car, and it's much easier to maintain. As a car’s engine and pollution control equipment age, most gas cars eventually become gross polluters towards the end of their life. You can still see older cars on the road that emit smoke. Central power plants are monitored to prevent this kind of degradation in pollution control.

Also, when you upgrade a power plant, you upgrade all the cars depending on it. Even though existing grid power is already cleaner than burning gas, it can still be improved. Even the coal plants out there now with little pollution control will be upgraded at some point. For example carbon capture (sequestration) is now possible which can’t be done in a gasoline burning car.

With grid power, besides coal, you also get quite a bit of hydroelectric, nuclear, and natural gas that are all very clean. And as you change the mix of power sources on the grid, you again upgrade all the cars depending on it. Renewable power is growing and solar, geothermal and wind sources are all increasing. As these clean sources expand, grid power becomes cleaner.

And as a side benefit, all those grid power sources mentioned including coal are largely domestic, so you remove most of the national security problems associated with our dependence on foreign oil when you go electric.

Finally look at all the CO2 you’ve saved. For just the gas in your car the DOE says you’ve saved almost 20 pounds of C02 per gallon not consumed. Then there’s the CO2 saved delivering the gas from the refinery to the gas station. The CO2 saved refining crude oil into gasoline. The CO2 saved delivering the crude oil to the refinery (from US or overseas). The CO2 saved drilling for the crude oil, or burning off the natural gas by-product. That’s some savings.

PDK-
I was really motivated to save fuel when this site reminded me that it was Patriotic. People want to be a part of something thats positive. When I discuss/argue/debate I look for the emotional appeal that's positive. Unfortunately, knowledge of facts rarely changes behavior. I think the Cadillac commercial illustrates this well: it lists all the features, dismisses them and then states "the real question is, when you turn your car on, does it return the favor?"

Rarely is the argument being presented the real reason for resistance. And depending on your audience, saving the earth may not be as powerful as being pro-American.

Once you've hooked them, then you can educate them on the details.

People forget that electric motors are ~95% efficient, even if the coal burning is ~35% efficient at producing electricity (about a low end according to wikipedia), you still get ~33% well-to-wheel efficiency. That's still a huge improvement over the ~20% mechanical efficiency of ICE. Even if we call the transport of fuel a wash it's a huge win (though I think moving a lot of coal to one place is better than moving lots of gas to hundreds of places). Plus, you have the huge win of more easily sequestering the GHG and smog emissions.

You left out transmission and distribution losses which, according to Wikipedia, are estimated at an average of 7.2% in the US, which drops efficiency to about 30%, and then there are battery charging losses (NiMh charging is only 66% efficient per Wikipedia) which puts efficiency back at around 20%--the efficiency margin is not what you think. We would want our new coal and natural gas plants to be efficient (35% efficiency a reasonable assumption for current new coal plants) and close to power users (not a reasonable assumption in NIMBY suburbia).

Not that I oppose PHEV's, but we need to cover our bases when we talk efficiency numbers. For example, with current technology, we probably wouldn't improve total automotive energy efficiency by powering the grid with gasoline powered generators to charge electric cars, which your numbers might suggest.

Is there any quick rebuttal that might actually get people to listen? What do you guys say?

I haven't actually debated it, but maybe one source of cleaning up is easier than multiple sources.

Another is that electricity is more efficient than ICE. Though then you might have to get into
proofs.


--des