EV's: They're Only as Green as Your Grid's Fuel

Hi Zythryn,
This is the latest article I could find:
http://pubs.its.ucdavis.edu/download_pdf.php?id=1145
It has a nice bibliiography too

Note that the study was for California. Here is the abstract

 

While there are some differences of opinion, I understand your viewpoint. Lets come back in 10 years and reexamine. I fully agree with your second point, Economics is the major determiner of most choices. I would acknowledge your first viewpoint if there were enough EVs to actually require measurable marginal demand on coal plants, but that is not true right now, and I'm not sure when it will become true. (Hopefully soon....but then your viewpoint does carry more weight.)

My viewpoint was heavily influenced by my initial Prius purchase back in 2001. Every analysis that was put in front of me showed that the Prius did not make economic sense. My major complaint back then was that every analysis was based on linear extensions of 2001 gas prices holding steady for (only) the warranty life of the car......and that the only basis for a car purchase was what a spreadsheet said. It looks like the EV is occupying the same initial position in this discussion.

Lastly, It's also clear that this is something of an academic discussion and that you are definitely thinking about decisions and consequences....something in very short supply overall.

 

FL stated it very well and in words better than I could have. So I will simply say: "Ditto!"

I also don't believe I have stated this: I agree with you SageBrush that conservation of energy use balanced with quality of life is always the most economical step.

 

There's no double standard, only a reminder to consider possibly in-obvious facts and their consequences. Anyone who buys a Prius surely does not imagine that their GreenHouse Gas emissions will be zero. In most cases, the premium they paid to reduce their GHG emissions will actually buy some GHG reduction versus any other car they might have bought, with no other consideration or action on their part.

In contrast, someone buying an EV with no thought about the source of the electricity used to power it may well imagine that their automobile GHG emissions will therefore be zero; they would almost certainly be wrong. If they a paid a premium for an EV that's powered by coal, then that premium was wasted.

Notice that I'm not talking about an economic payoff to the individual. Considering only direct costs, most people would have a lower total cost of ownership buying something other than a new Prius or a new EV.

 

If they bought an EV to reduce GHG emissions but their EV is powered more than (roughly) 50% by coal, then the premium they paid for the EV was wasted because it bought no reduction in GHG emissions. If their electricity comes mostly from coal, which is all too common in the US, then they have increased GHGs versus operating a Prius. They would have done better to buy a Prius, or to buy 100% non-fossil electricity for household use.

Now, if they bought an EV to reduce dependence on petroleum and don't care about GHG emissions, coal mining, or pollution from coal-fired power plants, then they certainly achieved their goal.

 

Thanks for the comments and interesting discussion! I must say though that I am not trying to put a viewpoint out for consideration, but rather advance a qualitative conclusion regarding the environmental benefit of EV over Prius. FPd has staked his position, that current models are too fuzzy for him to worry about one way or another. I can relate but am interested in hearing a critique of the variables and assumptions that cause the most skepticism.

I well remember the endless discussions whether Prius saved money, and the lame assumptions often introduced into the discussion. On the other hand, Prius as a conservation measure was widely accepted from day#1 by reasonable thinking people, while ignorant naysayers and CNW Marketing were rightfully dutifully ridiculed.

I hope at least I come across as earnest and reasonably deliberate in my conclusions, although certainly I may be wrong. I suppose in this case I am a skeptic, but I assure, not of the self-declared variety we too often see pop up on PriusChat like moles that one should simply whack back into their holes. As I have mentioned, I am enthralled by electric transport, and derive no satisfaction *at all* by finding that its high cost cannot be mitigated by exceptional environmental benefit. My heart says EV!; my head says not so fast.

 

You are repeating yourself.

This has been an excellent discussion, whatever a persons point of view, there is a lot of food for thought here. :thumb:

 

I would absolutely agree that getting an ev or even a prius does not get us very far in reducing GHG. Bringing up coal as a measure of polution is really asking the wrong question when it comes to energy use and vehicles. Even when framing it this way, the marginal electricity demanded by the ev or the phev should be considered, not the convolution of the utility assigned to it as if it took the most polluting old power plants. In the cases where it is higher, the body doing the regulation of the utilities really has put the value of public good of clean air at 0 or more likely less than 0.

The oldest most polluting coal plants can put out as much as 1600 g/kWh and are inefficient. New plants that use integrated gasification combined cycle are up to 45% efficient and emit less than 700g/kWh as well as extremely low levels of NOx and SO2. They as well as natural gas combined cycle (up to 85% efficient) can easily be modified to sequester carbon dioxide emitting less than 100g CO2/kWh. The problem with the clean coal technology is that in many cases it is more expensive than building wind power.

Good link, I had no idea some of those states caused so much pollution. ND has 1017g/kWh, which if we give a 20% penalty for charging batteries and transmission, and use 4 m/kwh gives us 305 g/mile. This is really the worst case. NM is not far behind at 915 g/kWh and the abundant sun and wind power really gives that state no excuse. It seems the uggliest most inefficient coal plants are grandfathered into existance. Those incentives need to go away. I doubt any state by 2020 will be creating more greenhouse gas on an phev than a hybrid. Right now there are only a few.

 

Easiest way to achieve this "savings" is to increase the cost of gasoline to something near what it really costs us - Actually make people pay that at the pump instead of hidden in so many other areas. When gasoline is $10+ per gallon, then we can revisit what the cheapest auto fuel/tech is.

 

Amen

 

ahem,
If the nations resources are squandered on fossil_fuel-EV, the root problem of fossil fuel reliance is not dealt with. As you point out though, fossil fuels have a myriad of bad side effects, and so long as the root problem is dealt with, it really does not matter which side-effect is the choice "worse one."

However, if one side effect is dealt with -- even successfully -- but ignores or worsens the others, then we have disagreement.

 

I could go for that if I had the slightest belief that the money collected from an increased gas tax wouldn't just be extra money to be urinated away on something else.

 

^^ very true -- always a problem. However, at least in my mind, the tax is not there to be collected, but to "encourage" people to conserve.

 

Good point, taxes would encourage conservation.
In the best case scenario it would also increase funding to cleaner energy research and implementation. Worse case, it encourages conservation but does nothing to support research and implementation. The reality is most likely somewhere between the two.

 

Disagree, in part.
If one side affect is dealt with and others remain at the status quo, it is an overall improvement.
I do agree though that if one side affect is dealt with and another is worsened, then we have more investigation to do.
Best case, of course, would be that all negative issues are dealt with. But you can't let 'perfect' be the enemy of 'good'.

 

The practical problem is limited resources aka money. If imported oil dependence is lessened through say expensive Canadian shale use in EV, one side effect of fossil fuel dependence -- subsidizing terror -- is lessened. But that much less money is available for pollution control, grid improvement, and AGW.

So I don't see this as a case of starting with 'good' instead of waiting for 'perfect', but one of competing interests for a limited resource.

 

What do you mean by Canadian shale use? Do you mean oil shale or tar sands? There would be absolutely no reason to use them with EVs. The massive amount of energy used to produce liquid fuels from them could instead be used to power a huge number of EVs.

 

I'll say - I grew up across the street from/with Ryan McCarthy. I'll have to give him props on the paper next time I see him.

 

I mentioned having the state's collect the tax instead of nationally. You're homing in on the reason why. No doubt, if collected nationally, the tax could be used to "encourage" more fossil fuel subsidies. In all cases it would not be used to reduce the national debt. If collected by the states, the vast majority would be used to fund the basic state budget, with only a few states (Texas?, Alaska?) funding the oil industry.