Charging cars at home at night is not the way to go, Stanford study finds

[ÆCIII]

It's amazing how a group in academia who've never innovated or implemented a charging infrastructure at scale themselves ever before, will then somehow conduct a 'study' to tell others they are 'doing it wrong' even as those others are the true pioneers, the first to succeed and participate in it, and are the only ones with real charging experience and vast amounts of charging data.

Agendas will always change how studies are conducted and through what technical, political, and emotional 'lens' that data and observations are included and evaluated. Today's universities unfortunately, are no longer focused in pursuit of pure academic substance and disciplines of arts, science, math, language, and technical skills, but instead are distracted by agendas and political fads embracing activist groups and sometimes actual contradictions to proven science, often having really lost their way.

When pursuing degrees some time ago, I noted there were about six major university accreditation institutions in the United States, and I gave no second thought about the integrity of any one of them and would've been proud of such an accredited degree on my resume. Today, my faith in these same accreditation institutions is near zero, and doing it over I'd be sure to explicitly show qualifications on my resume that would not leverage and reference to these institutions, but instead show my actual academic accomplishments in other ways.

I liked some of Elon's past comments on how he views job applicants with university degrees and how he weighs them in very careful context with a lot of other qualifications, because he knows the true educational substance and innovation skills often have gotten lost and may not always be internalized as abilities and skills in an applicant just because they show up with a 'degree' on their resume. He is so right.

I'm sure there are still solid curricula remaining in a lot of schools, and my views expressed above might not be fairly expressed broadly for all universities.

But, if Stanford really had meaningful expertise in EV charging, they would've been the one's to innovate the NACS standard over the past few years, and they would've been the one's to open it up and then encourage Tesla and others to adopt it from standards they would've refined, tested, and verified for years by now. If they were such experts and this were the case, Tesla would be adopting the NACS standard from them. But this is not the case, and I see those at Stanford as commenting from the sidelines all of a sudden while Tesla has been blazing the real 'trails', doing the real work of innovation, and actuating future development for the way forward. Stanford peers are just writing in the wake of Tesla and others' accomplishments, without vast data and vast experience of their own. It's just my opinion, but I know many other who also share it as well.

I charge mostly at night, because it saves money and also is less likely to cause excess demand on the electrical grid. It is also a concurrent activity because charging at night is occurring while one sleeps, so therefore it is an efficient use of time and less likely to conflict with activities or sudden transportation needs. These are logical and common sense reasons which no university 'study' will ever be able to refute for my purposes.

- ÆCIII

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[fhteagle]

OK, let’s look at Elon’s claim on its face: 5 kWh/US gallon is about 5/35.3 kWh or about 14% of the lower heating value (LHV) of a gallon of gasoline- but only if you were to convert the LHV (heat units) into electrical energy (kWh) at 100% efficiency. Ding! There’s the error!

This set of sentences is a textbook study in logical fallacy and rhetorical argument that sounds good, but doesn't stand up to any scrutiny at all.

The author of that LinkedIn post focused on the thermochemical inefficiencies in one step of the refining process, which is only one part of a very very very long production and distribution chain. This number is coincidentally similar to a rough and likely low estimate for the number of kWh it takes to pump crude up from a well, pump to a refinery, pump again within the refinery, pump cooling water into that refinery, pump finished products back out a distribution station, pump again into a truck, pump again out of an underground holding tank into a vehicle, etc. Apples to oranges. They may have a similar mass, but they are not the same fruit.

And that waste figure doesn't even come close to accounting for the energy wasted in flaring natural gas from crude oil wells because it isn't "economically efficient" to collect and clean that natural gas. Or the amount of hydrogen (again made from natural gas) that it takes to refine crude oil. Use any or all of that primary fuel in an efficient NG fired power plant to charge an EV instead! It's not even funny how many kWh we aren't making because the fossil fuel industry is used to getting away with being wasteful!

 

[cvalue13]

The author of that LinkedIn post focused on the thermochemical inefficiencies in one step of the refining process, which is only one part of a very very very long production and distribution chain.

did you read the rest of the post?

Or let me come at it a different way:

You show me *your* work supporting the veracity of the following:

“You take an average of 5 kilowatt hours to refine gasoline, something like the Model S can go 20 miles on 5 kilowatt hours. You basically have the energy needed to power electric vehicles if you stop refining.”

mind you in the answer:

(1) the point is if you stop refining then you have the electricity needed to power electric vehicles, and

(2) with electricity being 15% of power used in refining, and the most of that 15% produced by cogeneration

with that, have at it:

 

[fhteagle]

did you read the rest of the post?

I did, in fact I had stumbled upon and read that entire post at its original location about a week before you copied it as part of re-researching this question yet again. I liked where he started the post, and where he finished it up with, but the meat in the middle bugged me the first time I read it, and even more so when you copied it here. The same way the ANL / GREET publication (now more than two decades old) that the post author linked to bugged me. Both are cherry picking some start and stop points in the analysis, graphs, etc. and therefore missing huge portions of the big picture. "In calculating the energy efficiency of petroleum recovery, the energy (in Btu) in the flared and/or vented gas is not accounted for because it is not an intended energy source." Further, I believe the GREET model may be not accounting for some important inputs to the production cycle, like the hydrogen used up in refining.

You show me *your* work supporting the veracity of the following:

“You take an average of 5 kilowatt hours to refine gasoline, something like the Model S can go 20 miles on 5 kilowatt hours. You basically have the energy needed to power electric vehicles if you stop refining.”

I cannot prove the tweet as literally written, because Elon messed up when he wrote "refine" gasoline. I believe that step only may have somewhere on the order of 0.5 to 0.9 kWh of actual electricity as an input to the production of a final gallon of gasoline. If Elon was using "refine" as shorthand for the entire process of extraction, transport, side input creation, actual chemical reacting of the feedstock, blending, marketing, etc (which I suspect is how he meant it, but truncated that inaccurately for the tweet character limit), then that is much easier to support because I believe that is more accurate. One step further, the idea that it is more efficient and desirable to stop all of the inputs to the fossil fuel system, and redirect even the input only primary energy (not even the extracted feed stocks) into efficient grid-connected power plants as a backup and supplement for renewable sources, or better yet into infrastructure to make and store renewable energy sources, should make for a very interesting analysis.

I am pretty fired up about this, and will not get it it done today, but I do intend to get better than napkin math level analysis done about it. I am talking about digging up data like how many pump jacks are out there operating, how many are run via electric motor or run from a fossil fuel engine, how much electricity does a single pump jack use, etc. I have already reached out to someone who consults on global energy policy for a living, and therefore might be able to get even more solid numbers more quickly than I can. This kind of thing is right up his alley.

Why am I so fired up? Because "the grid isn't green yet (and just keep on ignoring how dirty the entire fossil fuel economic system is!), so do not transition towards EVs" is a favorite weapon of the FUDsters great and small (and accidentally supported in a LinkedIn post by someone who loves EVs enough to do a home made conversion), and the more of those weapons I can diffuse, the happier I will be. So, in short, (modified) challenge accepted, and standby for a bit until I can do a proper job of it.

 

[cvalue13]

Both are cherry picking some start and stop points in the analysis, graphs, etc. and therefore missing huge portion of the big picture.

First things first, that we all agree that electricity should be used to power vehicles, means this is all just academic masturbation. The conclusion is agreed.

But if we're heading down that academic path, then this "cherry picking" framing is a misstep generally, as well as the misstep in specifically responding to the assertion being responded to.

start with the general misstepp:

if you’re going to move the relevant calculation line, then of course they didn’t count “everything” - that’s definitional to having moved the relevant calculation line.

and every time you move the relevant calculation line, the next person can, too.

eg on the electricity side, they next say, “ok, but now you have to also calculate the petrochemicals/emissions used to create electricity transmission lines, the emissions attributable to the hamburgers eaten by the crews who maintain the emissions lines, and for that matter the emissions attributable to the cooking of the fruitcake Thomas Edison was eating the day he had the idea to use carbonized bamboo as a filament.

Call that "cherry picking" if you like. But it seems more like what you're really doing is saying "i dont agree with what they want to talk about, I want to talk about a different thing altogether."

The initial agreement has to be: do we agree to talk about whether the calculation is to be confined to just the actual refinery processes to change crude oil into petrol, or are we instead agreeing to talk about the entire process from initial prospecting of hydrocarbon vs electricity feedstock, planning of infrastructure, etc., through to the point conversion of power to the axel of a vehicle.

If you want to talk about the latter, then find your counterparty.

which brings to the point about a specific misstep:

The folks discussed above instead agreed to talk about the calculation confined to just the actual refinery processes as relates to electricity used therein that would otherwise be available to EVs.

If you feel they've agreed on the wrong thing to talk about, that's fine. But that does not mean you can say their conclusions are "wrong" because of it. That's the equivalent of two people saying "let's count the apples and oranges in the supermarket, the answer seems to be either 100 or 50," and then you injecting "you're wrong, because there are 500 fruits in the supermarket."

If they've instead all agreed on a defined question, such as the number of only apples and oranges in the supermarket, or the total energy a refinery uses to produce a gallon of petrol as it relates to electricity that would otherwise be available to EVs

• a ~40kWh gallon of petrol takes ~4.8kWh of energy at the refinery
• of that ~4.8kWh of energy, only ~15% is from electricity (most is instead steam and heat)
• of that ~15% from electricity, the majority is co-generated on site (using local feedstock)

Under no maths does this glimps towards refineries using electricity that would otherwise be available to EVs in sufficient quantities to more efficiently power EVs

Because "the grid isn't green yet (and just keep on ignoring how dirty the entire fossil fuel economic system is!), so do not transition towards EVs" is a favorite weapon of the FUDsters great and small ....

That's all well and good, and true. But to combat it, one has to make choices about persuasiveness as much as facts.

And I point out that, confusing what *you* are interested in talking about with what others are talking about is a misstep in persuasiveness.

That's the difference between saying, for example:

"yes, Elon was wrong or misspoke, and people shouldn't be repeating that error because to the extent it's demonstrably false on its own terms it reflects poorly on our persuasiveness, and in any event it's not a relevant question for the following reasons...."

vs

"this guy on LinkedIn is using a logical fallacy and cherrypicking data and there are 500 fruits in the supermarket not 100 oranges and apples"

 

[CyberGus]

First things first, that we all agree that electricity should be used to power vehicles, means this is all just academic masturbation. The conclusion is agreed.

But if we're heading down that academic path, then this "cherry picking" framing is a misstep generally, as well as the misstep in specifically responding to the assertion being responded to.

start with the general misstepp:

if you’re going to move the relevant calculation line, then of course they didn’t count “everything” - that’s definitional to having moved the relevant calculation line.

and every time you move the relevant calculation line, the next person can, too.

eg on the electricity side, they next say, “ok, but now you have to also calculate the petrochemicals/emissions used to create electricity transmission lines, the emissions attributable to the hamburgers eaten by the crews who maintain the emissions lines, and for that matter the emissions attributable to the cooking of the fruitcake Thomas Edison was eating the day he had the idea to use carbonized bamboo as a filament.

Call that "cherry picking" if you like. But it seems more like what you're really doing is saying "i dont agree with what they want to talk about, I want to talk about a different thing altogether."

The initial agreement has to be: do we agree to talk about whether the calculation is to be confined to just the actual refinery processes to change crude oil into petrol, or are we instead agreeing to talk about the entire process from initial prospecting of hydrocarbon vs electricity feedstock, planning of infrastructure, etc., through to the point conversion of power to the axel of a vehicle.

If you want to talk about the latter, then find your counterparty.

which brings to the point about a specific misstep:

The folks discussed above instead agreed to talk about the calculation confined to just the actual refinery processes as relates to electricity used therein that would otherwise be available to EVs.

If you feel they've agreed on the wrong thing to talk about, that's fine. But that does not mean you can say their conclusions are "wrong" because of it. That's the equivalent of two people saying "let's count the apples and oranges in the supermarket, the answer seems to be either 100 or 50," and then you injecting "you're wrong, because there are 500 fruits in the supermarket."

If they've instead all agreed on a defined question, such as the number of only apples and oranges in the supermarket, or the total energy a refinery uses to produce a gallon of petrol as it relates to electricity that would otherwise be available to EVs

• a ~40kWh gallon of petrol takes ~4.8kWh of energy at the refinery
• of that ~4.8kWh of energy, only ~15% is from electricity (most is instead steam and heat)
• of that ~15% from electricity, the majority is co-generated on site (using local feedstock)

Under no maths does this glimps towards refineries using electricity that would otherwise be available to EVs in sufficient quantities to more efficiently power EVs



That's all well and good, and true. But to combat it, one has to make choices about persuasiveness as much as facts.

And I point out that, confusing what *you* are interested in talking about with what others are talking about is a misstep in persuasiveness.

That's the difference between saying, for example:

"yes, Elon was wrong or misspoke, and people shouldn't be repeating that error because to the extent it's demonstrably false on its own terms it reflects poorly on our persuasiveness, and in any event it's not a relevant question for the following reasons...."

vs

"this guy on LinkedIn is using a logical fallacy and cherrypicking data and there are 500 fruits in the supermarket not 100 oranges and apples"

I do see many petroleum-supporters shouting about the vast amounts of carbon needed to build batteries, including in the mining. But when calculating the carbon of ICE vehicles, they count the gasoline emissions as if the gas stations were built over a subterranean "regular-unleaded" lake.

 

[Coolbreeze704]

I do see many petroleum-supporters shouting about the vast amounts of carbon needed to build batteries, including in the mining. But when calculating the carbon of ICE vehicles, they count the gasoline emissions as if the gas stations were built over a subterranean "regular-unleaded" lake.

Well then this looks even more ridiculous.

 

[Ogre]

I do see many petroleum-supporters shouting about the vast amounts of carbon needed to build batteries, including in the mining. But when calculating the carbon of ICE vehicles, they count the gasoline emissions as if the gas stations were built over a subterranean "regular-unleaded" lake.

After 30 years of operation, most gas stations have quite a supply of “regular-unleaded” in the soil beneath.

 

[cvalue13]

I do see many petroleum-supporters shouting about the vast amounts of carbon needed to build batteries, including in the mining. But when calculating the carbon of ICE vehicles, they count the gasoline emissions as if the gas stations were built over a subterranean "regular-unleaded" lake.

Yes, people have dumb and/or unpersuasive arguments

The aspiration to not be one of them

(At least in real life - forums anything goes)

 

[HaulingAss]

Employers wouldn't offer workplace charging if they didn't want their employees charging. A lot of the early adopters of the Model S and Model X were business owners who wanted to spread the goodness of driving an EV to their employees.

Employees are the most valuable resource any business has, treat them right, and your business has a much better chance of succeeding. If your employees have a long commute, you are going to have to pay them more to retain them because filling their tank and keeping their ICE car running and serviced is taking up an inordinate amount of your employees' time and resources. If your employees drive EV's, employers can draw qualified employees over a larger area due to the better economics of powering the commute with electricity. If your employer offers free charging, you have an even better incentive to stay there, and other employees that still drive ICE have an incentive to reduce the cost of their commutes by going EV also.

If you plug into an outlet at an employer who doesn't offer free EV charging for employees, then you are an idiot and should be fired for that reason alone. Common sense says you need permission to take someone elses things, even if it's only a pencil. Nobody wants employees without common sense or, worse, with a sense of entitlement.

 

[CyberGus]

If you plug into an outlet at an employer who doesn't offer free EV charging for employees, then you are an idiot and should be fired for that reason alone. Common sense says you need permission to take someone elses things, even if it's only a pencil. Nobody wants employees without common sense or, worse, with a sense of entitlement.

 

[fhteagle]

First off I want to preface this with when I say "fired up" I mean interested in, not angry about. I know that is not common behavior for internet forums these days. I will happily debate to the point of attacking facts, figures, ideas, logical construction, but I try hard not to attack people, so please do not ever take what I say as a direct attack on anyone personally.

First things first, that we all agree that electricity should be used to power vehicles ... The conclusion is agreed.

Agreed

... means this is all just academic masturbation.

Definitely not agreed, for about a hundred reasons.

if you’re going to move the relevant calculation line, then of course they didn’t count “everything” ... and every time you move the relevant calculation line, the next person can, too.

Moving the calculation line is exactly what I was calling foul about in the LinkedIn post. The author moved the calculation line to the refinery fence, to the absolute minimum plausible interpretation of the verbiage of Elon's statement. The refinery fence as "boundary of the system" in a topic so complex as gasoline production is so tight as to be absurd and useless. Just as your "including Edison's lunch" argument as an attempt at reductio ad absurdum is. By doing so, you added weight to my argument without realizing it, and for that I thank you.

Where you draw the boundary conditions (AKA context) matters, and can easily change a fact and figure from correct/accurate/persuasive to wrong/inaccurate/nonpersuasive. Tying this back to the original point of this thread, if I ask the question, "when is the best time to charge my EV?" I get different answers with different boundaries of the system I consider. If I consider only my electric meter and bill, I get the answer of 'anytime', because my electric co-op has no TOU rate structure. If I consider the entire co-op, I see that we are pretty heavy on both utility and behind the meter solar, and come up with the answer of "charge during the day". If I take the entirety of my Balancing Authority (which includes a lot of coal generation two giant states away), I get the answer of charge at night when the coal plants are throttling down. If I take the entire Western Interconnect, I get....

To continue your fruit and grocery store analogy, you and the LinkedIn post author are attempting to verify how many fruits are purchased per customer by only inventorying the freezer section. So, no, not agreed to the rules you are proposing for how to do the calculation.

I did not have time to start any real research on the topic yesterday, but I did stumble across this:




TL; DW: using 2021 EIA data for "Purchased electricity (kWh)" in "Fuel Used at Refineries" from https://www.eia.gov/dnav/pet/pet_pnp_capfuel_dcu_nus_a.htm divided evenly across "Finished Motor Gasoline" from https://www.eia.gov/dnav/pet/pet_pnp_refp2_dc_nus_mbbl_a.htm ,

I get 2.2 kWh per gallon. Call that a plausible upper limit on purchased kWh consumed inside the refinery fence. If gasoline is 46% of the output of the refinery in the US from https://www.eia.gov/energyexplained/oil-and-petroleum-products/refining-crude-oil.php , then you could also make a reasonable argument for ~1.0 kWh per gallon instead, and I will call that plausible too.

 

[cvalue13]

The refinery fence as "boundary of the system" in a topic so complex as gasoline production is so tight as to be absurd and useless. Just as your "including Edison's lunch" argument as an attempt at reductio ad absurdum is. By doing so, you added weight to my argument without realizing it, and for that I thank you.

definitions and boundaries of questions have to be agreed first for resulting discussion to be meaningful.

It seems part of the miscommunication here is you’re not understanding the context or content of the claim being discussed. And before I cite it, I want to be clear about one thing: I’m not trying to hold Elon to this comment from 2011, nor do I think he would assert it or maintain it today, nor do I think Elon was as educated on it in 2011 as he is today.

I’m instead saying that this incorrect assertion from 2011 continues to be regurgitated ever since, and it’s a bad look for those who want to be persuasive if only by factual support:

Here’s the interview (not tweet) with Business Insider, and context of the comments from both Chris and Elon:

​

BI: At least in the U.S., most electricity is generated using fossil fuels. Mostly natural gas and coal. What's the relative carbon footprint of a Roadster or Model S, against a gasoline car? I've heard that argument from people who worked in the oil industry.​

​

Chris: It's funny they make that argument, because they're one of the largest users of electricity in the country, to refine gasoline. That's why the power cords go into refineries. Something like 4 to 6 kilowatt hours of electricity to refine every gallon of gasoline. They're pulling that electricity from the same source as they're critiquing on electric cars and they get much less result out of it.​

​

Elon: Exactly. Chris has a nice way of saying it which is, you have enough electricity to power all the cars in the country if you stop refining gasoline. You take an average of 5 kilowatt hours to refine gasoline, something like the Model S can go 20 miles on 5 kilowatt hours. You basically have the energy needed to power electric vehicles if you stop refining.​

​

BI: 5 kilowatt hours, that's to refine and transport one gallon of gas?​

​

Elon: Chris, does that include transportation?​

​

Chris: I think it's just refining. It does not include transporting it …​

​

​

Accordingly, the inaccurate assertion was about the amount of electricity that would otherwise be available to BEVs for charging, used by refinery plants. And it was that same framing that was being deployed by others in this forum post.

this is why, I don’t take the LinkedIn poster, nor myself, to be remotely interested in disputing the well-to-wheel all-in energy chain: because the results of that calculation are patently obvious and agreed, and the underlying reason we agree electricity should be fueling our vehicles - and why I characterized this separate, limited, inquiry as being “academic masturbation”


When instead, the intended conversation is past and assumes that background. It merely moves on to separately ask in effect the following sub-set question:

“understanding and agreed that electricity should be used to move our vehicles given the all-in energy and emissions consequences from wheel-to-well, within that chain what role exactly does petrol refining play in absorbing electricity that could instead by directed to the grid for EV charging”

to which question you seem to be responding: “but it takes more energy wheel-to-well”

to which I respond: “ok but you see we’re now wondering, admittedly in academic masturbation, what role this specific link plays in that chain … and whether people should be regurgitating a patently inaccurate assertion about the role played by this specific link in the chain, lest the undermine the credibility of the broader point RE well-to-wheel disparities”

 

[CyberGus]

to which I respond: “ok but you see we’re now wondering, admittedly in academic masturbation..."

 

[kbolt]

Agree with all of this. Two additional points I'd like to add.

1. You've not seen my mother-in-law doing laundry. That dryer absolutely is capable of being run 5+ hours per day!!

2. I think the average commute is something like 30-ish miles? Even if we round up to 40 as an average, that would mean most EVs would only charge for 1-2 hours per day, most days. Maximum 3. That's including power-hungry vehicles like the Cybertruck.

Let's assume a 40-mile round-trip commute. Worst case (or lead foot) we get 2mi/kWh, so that would mean using 20kWh for that commute. Even if we only install a 32-amp capable level 2 charger, that's, approximately 6.6kW going into the vehicle (rounding down to commercial voltages). So absolute worst case is charging for 3 hours for an average commute.

If the commute is 30mi and we can draw a full 48-amp (11kW) level 2 at home (what I have installed) then we're talking 1.5 hours tops at 500Wh per mile. My wife's Model Y would recharge in less than an hour (which is what we typically see).

But the biggest difference that I see is that we're looking at a continuous draw for that time. A relatively quick ramp up to 32/48A and an abrupt end at that amperage (or rapid taper, perhaps) when the charging limit is reached (assuming not charging to 100%). Even dryers don't use the full 32A continuously. It's a spike to get up to temps and then a lower amperage to maintain those temps.

Minor nit: I drive into town once a week to get groceries and that is about 60 miles. My car charges at 4-5 miles per hour since I use a standard wall outlet. So it's not 1-2 hours of charging per day that people using a standard outlet will need, but rather 6-8 hours if they travel 40 miles per day.

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