Toyota November Tops US Electric Plug In Vehicle Sales For November

And should not be, lest it be confused with electric or fossil fuel vehicles.

 

MPG ignores the efficiency of the fossil fueled power electricity that went into refining the gasoline. The sweet, easy to get crude has EROI of 1 to 17. For tar sands it's 1 to 6. Should we say a car burning tar sand gas is only getting a third of the MPG it actually gets?

You don't like MPGe because it ignores the upstream. Fine. What should we use instead to inform the public about the efficiency of the cars using varying energy sources, some two, seperate and at the time, that they can choose to buy? Do you want a fudge factor to cover the electric energy generation in there for plug ins. MPGe for EVs includes the charging loses. Shouldn't there be an accounting of the electricity the pumps used putting the fossil fuels into the car then?

Maybe we should just drop all the Wh/mile, MPG, etc. and just slap the dollar cost to go 100 miles on the sticker. That's really what the public cares about.

You would be a fool if that was the case.

MPG and MPGe tell a person how far a particular car can go on a measured amount of an energy carrier(they all are going back far enough) with measurement taken from the pump or wall as the case may be.

So the EV isn't penalized for the inefficiency of how its electricity was made. The ICE isn't penalized for the inefficiencies of making the gasoline from different sources be it sweet crude, sour crude, tar sand, oil shale, natural gas, or coal.

 

Yes but the loss is about 15% to refine and transport.

Electricity generation loss is 50-70% loss depending which fossil fuel, minus the transmission loss.

 

you could ask a question of PC'rs .... " What does it cost you to go 100 miles". For me that's 20kWh at the wall via PV. But just imagine all of the other things you could include As part of what it cost you to go 100 miles ... tires - registration - depreciation - replacement traction pack - brake job and other maintenance costs ... etc. And that's just the electric motor side of things. It's a slippery number to nail down.
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SGH-I717R ? 2

 

And the electricity used in the refining process has a 50% to 70% loss.

What about the losses getting a product to the refinery?

The complaint for using MPGe for electricity(and hydrogen) is that it doesn't consider generation method, and the differing methods make it worthless to compare with gasoline. This assumes gasoline's feedstock and production is all uniform.

On a per gallon basis, the difference between getting gasoline from light, sweet and heavy, sour crude probably isn't enough to show up. These aren't the only sources of our gasoline. Tar sands are also a portion of our gasoline now. A lot of energy is used just getting it to the point of being pumpable to the refinery. Some diesel on the world market is made from natural gas. What are the efficiency losses there? Cost reductions mean next big gas price spike and/or shortage will see some coal sourced gas in our tanks.

The point is MPGe is just for measuring efficiency of a vehicle from the wall or pump. KWh/100 miles or Wh/mi would probably be better, but they still don't account for the efficiency of the power plant. That is beyond the scope of letting a car shopper know the amount of energy a car uses relative to another, though.

 

Overly simplistic on the loss.. Not sure of your source.

First not all feed stocks are close to the same.
For from the this NDRC report

Also note the WTW studies that suggest an average 85% yield are backwards looking from 2004, and did not include as large a fraction of tar sands, nor did they consider the power for finding the oil nor for the gas stations themselves, and generally ignored the escaped/flared gasses, all of which are non-trivial energy usages/losses.

A barrel of average crude produces about 30% gallons of gasoline by normal means which is what was in the orginal argonnee model WTW,
but deeper cracking/coaking needed to increase yield (to meet demand) and increased processing has also decreased energy. In this report
They report

So with that its efficency well to tank is now down to 80%..

But why consider Well-to-wheel efficiency . what matters the overall efficiency.. Which must include discovery. The following image shows the energy-return on energy invested for just oil discovery..


For the Discovery chart above, note that in the early days of oil exploration, the stuff was practically bubbling out of the ground, so it was much easier to figure out where to drill – hence the EROI over 1,200 in 1920. As the US industrial age found its legs, oil consumption accelerated. Demand for more and more oil quickly consumed the easy stuff, and the EROI fell rapidly. As we hit peak oil production in 1970, the EROI fell below 10:1. I inset a blowup of the chart, from 1950 to 2010, so that we can see how EROI has since remained firmly in the single digits. Note the "discovery" process does apply to NG, tough still at a much higher EROEI, and for coal the discovery process is minimal and overall EROEI for coal is about 80.

As the current discovery EROEI is in the single digits, currently about 1:7, and is multiplicative, then even if you presume production efficiency is 80%, the total EROEI is .85*.80 = 68% for Lifetime energy efficiency to produce gasoline.


And if you want to compare electricity generation to gas, you cannot just take some fossile fuel plants, you need to take the overall average ghg produced for kWh. The "efficiency" of nuke and renewable which together account for more than 32% of electricity, so your 30-50% efficiency effectively becomes 50-83%. Though of course, average is not as important as what the owner chooses to use for fuel.

 

Very interesting post Ddrinnovation, thanks. Do you have similar EROI data for extraction (mining) of oil and coal ?

It reinforces my point, however: if I pull up to a petrol station after choosing petrol vehicle 'A' or vehicle 'B', the upstream pollution losses and conversion efficiency, while certainly variable over time and place are nonetheless the same for that refilling. All I can do to affect the result is pick a higher MPG vehicle.

Likewise, if I pick an EV with a higher miles/kwh than an alternative EV, I have made the smarter EV choice.

What I cannot do is assume that just based on a higher MPG(e), an EV is a smarter environmental choice than a petrol vehicle with a lower MPG number.

 

When one factors in the huge decrease in discoveries, it's worth noting that the paltry new discoveries are nothing in comparison to the mega fields of the middle east .... which in some cases have been pumping & pumping for over a half century. So, not only have we made less discoveries, the paltry ones are, well, just that ... small in comparison to what we'd like. Couple that with the inevitable ... that the mega fields can't last too much longer, which drives up demand/costs. THEN, your new discovery costs go through the ceiling, because that old discovery energy that you use to find the new energy is costing a lot more. End of wet blanket.
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To nitpick a bit, IIRC the EPA says energy refining costs of oil to petrol are 15%; and if I am reading 1:7 corrrectly (the EROI) for oil, 1 in 8 parts of oil are used in discovery, or 12.5%. So the partial lifecyle would then be 0.85*0.875 = 74.4%.​

 

According to Energy returned on energy invested - Wikipedia, the free encyclopedia

EROEI for Coal (exploration and mining ) is about 80.
EROEI for imported oil (ignoring exploration) is 12
EROEI for shale oil is about 5.
EROEI for Tar sands is about 3
EROEI for corn ethonol is 1.3
This is wikipidia but the data seems about right to me.

MPG and MPGe are just measures to help understand one dimension of a complex process. They are measures of efficiency of energy usage, not environmental impact. Nor are they measures of economic impact.

Just picking a vehicle based on MPG or MPGe is not directly a smarter environmental choice, as there are many more factors than just the MPG/MPGe efficiency decision. Other factors include vehicle production energy usage to the the sources of the energy) as well as other externalities (e.g. military support for oil regimes, economic impact).

Just choosing the higher MPG (or MPGe) vehicle alone is not an environmental clear winner since there can be other issues (other polluants) as well as the potential personal application Jeveon's paradox where people can use higher efficiency to self-justify greater overall usage (e.g. drive more miles because they have an efficient vehicle).

 

Not sure which nit you are going after.. in part becuse the numbers were rahter similar.

An EROEI of 7 means that a investment of 1 returns a total of 7 (with a net gain being 6, not a net gain of 7), so it is 1 part in 7 is used for discovery or 14.2% (which I rounded to 15% for simplicity) to get the formula
.85 (discovery penalty) * .80 (refinery) = .68

I got the 80% as follows.
According to the 2008 Argonne publication (using data to 2006)
Argonne GREET Publication : Estimation of Energy Efficiencies of U.S. Petroleum Refineries
Efficency of the refinery (ignoring all transportation issues) for gasoline (excluding less desirable products such as road tar) was 83.3% (and its 87% if one inclues less desirable products in the energy mix), so the average of 85% efficiency is commonly used. (Note the GREET model pushes all added energy for shale oil and tar sands cracking "upstream" (i.e. does not consider their heavier processing burden) and also EXCLUDES transportation losses. (I don't know any good sources on that energy usage).

So I did start at 85% for refineries as of 2006


In the link I cited, on more recent issues in refinery efficiencies it said the US refineries have lost about 5% in efficiency since 2005, which is why I reduced from 85% to .85 * .95 ~= 80% refinery efficiency. Since the greet model was 2006, so some of the loss was already beein measured and I rounded crudely, I guess I should have made that 81%..

 

drinnovation,

Do you have some idea of the impact of switching the refineries to natural gas power? I saw something that indicated a 10% improvement, but that may have been a pure $ cost improvement. It seems domestic natural gas is increasing the yield of imported crudes. I think the folks putting together the Keystone project cited domestic natural gas integrated into the refining process as key to economic development of Canadian oil.

 

All refineries of which I am aware use a large amount of NG, so its not really going to be a "switch". NG is both a source of hydrogen for proper gasoline production from heaverier products as well as a source of energy for steam. Refining uses a lot of "steam" especially for dealing with tar sands and oil shale refining, and much of that is generated by burning some of the refining byproducts. Refineries also currently use a lot of electricity so I think you are referring to the trend for them to building their own NG co-generation facilities that simultaneously produces electricity and steam in more overall efficient manner with reduced losses (short tramission). Using NG cogeneration can allow them to reuse more of their own by-products to actually produce gasoline/disel and other profitable products and reduce their costs compared to buying commercial electricity.

Here is an old chart on the breakdown of energy used

* Losses incurred during the distribution, generation, and transmission of electricity.
** Includes LPG, coal, and other refined products.

 

We seemed to have gone way off topic from november plug-in sales, not that mpge isn't a good topic.

I created this thread for you all to discuss mpge and cafe. That way the next time we go off in the weeds we can refer back to a thread.
mpg, mpge, epa, cafe, switching and pollution | PriusChat

 

maybe a moderator can peel off the MPGe discussion into another thread.

 

Back on topic, hopefully the Nov. sales numbers are a start of growing market increase for the Prius line.

DBCassidy