Question about EV Value and environmental impact

[Topher]

Vinnie and I live in the SW US. I was hoping to hear about heat pumps. I have this notion that a well insulated home in my locale can time time-shift heating demands to the sunny and/or high COP hours. I would like to build off-grid with minimal fossil fuel back-up.

As for talking with a solar guy, well I can look up PVwatts just as easy ;-)
And have ... multiple times. Using pole-mounted PV that I adjust tilt a couple times a year, I can approach 1.9 kWh/watt*year maximum.

Well, a well insulated house in my climate can time-shift all the heating requirements. I heat my own house once a day, sometimes once every two days. However, heat pumps are generally sized to operate with a longer duty cycle. So it is likely you would need to upsize the unit.

1.9 kWh/pW-a is awesome. We squeak out an average of 1.1 around here.

Thank you kindly.

 

[SageBrush]

I heat my own house once a day, sometimes once every two days.

That is great! PassivHaus ? Did you energy model the home ? What results ?

heat pumps are generally sized to operate with a longer duty cycle. So it is likely you would need to upsize the unit.

Please explain

 

[Topher]

That is great! PassivHaus ? Did you energy model the home ? What results

Not quite to Passivhaus standards. Yes, I did an energy model on the house. What results are you interested in? Bottom line is that I use about 32 MBTUs per year for 7500 HDD (or 4,250 BTUs/HDD aka 1.25kWh/HDD).

Please explain

Typically when a HVAC engineer is sizing a regular heating plant for a house they will choose a size that will bring the house up to temp from typical outside temp in one hour. Needless to say, this is more than you will ever need. For a heat pump, they generally size much smaller, say 4-5 hours to heat similarly (particularly as COP decreases with cold ambient temp). So if you plan to heat only during daylight hours (to slightly higher temps), you may need a higher capacity heat pump system than might otherwise be recommended.

Thank you kindly.

 

[SageBrush]

What results are you interested in?

I have sort of gotten used to speaking PassivHaus
In terms of annual and peak power heating requirements per square meter ?

For a heat pump, they generally size much smaller, say 4-5 hours to heat similarly (particularly as COP decreases with cold ambient temp). So if you plan to heat only during daylight hours (to slightly higher temps), you may need a higher capacity heat pump system than might otherwise be recommended.

Got it. Thanks!

Are you the person who designed the DIY storm windows ?

I remember a guy from Maine who used to hang out at PriusChat also called himself an 'energy curmudgeon.' I think he was trained as an engineer, and worked as a home energy consultant. Ring a bell ?

 

[ChadS]

Please provide some credible evidence that it is significantly more than that on average or it's just a conspiracy theory.

It's true that oil refineries use a huge amount of electricity.

I am afraid I am not clear on what you're asking for. My claim was that refineries use a lot of electricity (2nd largest user in CA), and you agreed with that. You want evidence that "it" is "more than that"? I am unsure on the antecedents, and I didn't claim anything was more than anything else.

I suspect we really agree but one of us is not understanding the other.

 

[Jeff N]

I am afraid I am not clear on what you're asking for. My claim was that refineries use a lot of electricity (2nd largest user in CA), and you agreed with that. You want evidence that "it" is "more than that"? I am unsure on the antecedents, and I didn't claim anything was more than anything else.

I suspect we really agree but one of us is not understanding the other.

Yes, most likely we agree on the big picture. I was asking about the following statement:

Most of refining energy does indeed come from the oil stock itself. However, that doesn't mean there isn't still a lot of electricity used in petroleum refining. The oil industry won't report it, but the utilities know who uses their product.

What did you mean by "the oil industry won't reported it, but the utilities know who uses their product"?

Are you alleging an oil industry conspiracy to not report their electricity usage to the regulatory agencies that collect those publicly available statistics? Are you saying they are deliberately underreporting and their actual grid usage, known to the utilities, is substantially higher than the 3.5-5.5% grid electricity input to refining that the statistics show? If so, what is the evidence?

I wasn't sure how to parse what you were saying.

 

[ChadS]

I don't know that it has to be a "conspiracy" for refineries to not report fine details of their energy use, as I'd never heard of any regulation that they have to. But around four years ago I read two different sources on the same topic (one may have been an article, but I believe one was a peer-reviewed study - not sure I remember enough find it now) that said refineries did not report enough information to calculate how much grid energy is used per gallon in the refining process, but with some info from the utilities and some other assumed numbers, they were able to calculate a total. They were doing this specifically to counter the "it takes 7ish kWh of electricity to refine a gallon of gas" meme.

What do refineries report - grid electricity use? How much grid energy goes specifically in to the refining process? How much total energy goes in to the refining process? I don't remember the wording exactly enough. Maybe they report total grid electricity used, but don't define where in their operations it is used?

It would be interesting to know some more numbers, if they are out there. But this is largely an aside as I don't think we'll find anything that changes the two major points we agree on, which are that refineries use a whole ton of grid electricity, although the amount used per gallon is not terribly large. (The total amount of energy used per gallon for refining is shockingly large, but as pointed out most comes from the oil stock).

 

[Craig9080]

Parcels of roofs and parcels of air does not have quite the same bullet point impact, does it ?

I genuinely can't tell if your serious or not with that statement.

 

[Jeff N]

It would be interesting to know some more numbers, if they are out there. But this is largely an aside as I don't think we'll find anything that changes the two major points we agree on, which are that refineries use a whole ton of grid electricity, although the amount used per gallon is not terribly large. (The total amount of energy used per gallon for refining is shockingly large, but as pointed out most comes from the oil stock).

The latest studies tend to show that US refineries are, on average, about 90% efficient overall. Earlier studies tended to show 85-87%.

So, the electricity used in refining a gallon of gas is about 1/20th of the 10% energy loss from refining or somewhere roughly around .05% of the energy in a gallon of gas.

I actually think that is surprisingly good or at least better than I originally expected.

I don't know exactly how or under what regulation the numbers are gathered but I know they are broken out and reported in US government statistics and are also broken out as grid energy used at refineries and reported on a country by country basis in the online UN statistics at data.un.org. If the numbers were just reporting all grid electricity used in a refinery rather than just that used in the refining processes themselves it would, of course, tend to exaggerate the number.

If you look at the link to mynissanleaf.com that I provided a few posts pack on this thread you will see links to the database search pages at data.un.org.

 

[Craig9080]

Honesty I'm not a fan of weird radioactive waste that hangs around for that long. This isn't even a case of NIMBY -- I wouldn't wish radioactive waste on my worst enemies. It's NABY, or Not in Anybody's Backyard, because it will be bad for all of us. At least trees and plants suck up carbon, turning it into people-food. Nothing sucks up whatever random unstable atoms are left over after a nuclear reaction.

Okay, yes, it's not easy being green (must be true because a green critter said it!). Are we talking up-front costs here or ongoing costs? Solar is more affordable every year, and makes a great rooftop addition to almost any home. No one person has to pay all of this.

I agree that solar seems to be the best implementation for residential customers and I believe that most PV cells recoup the energy used to produce them at around the 1 year mark, so it's not long until you are in the green. When I was in college, me and a few friends rented a house in a city near campus and my room had windows that overlooked the first story roof, by the end of the first year I lived in that house I had a 90W solar array that I had wired to a controller that charged 220Ah worth of lead-acid batteries in my room. With an inverter I ran everything except the lights in my room off of solar - it was a great project for an engineering student and the urge to do it again will definitely bite on my next home.

The problem I see is leaning on residential solar as a means for energy independence. The numbers I threw up are in regards to a large scale solar farm that has adjusting panels and capitalizes on economies of scale, when we get into home installations the numbers only grow. Although mismanagement has occurred in the US nuclear waste management process (I dont know much about the Canadian process), the impacts are still localized and small compared to hydrocarbon energy production - which we all agree is bad, either from a North American energy independence perspective, or from an environmental perspective. I would honesty be OK with nuclear waste being stored near me - heck - the university i went to had a small one on campus less than 1/2 mile from my freshman dorm! To be clear though, the policy makers are the only part of that equation that would give me worry, I trust the science of the containment systems and the engineers who design them.

 

[Topher]

I trust the science of the containment systems and the engineers who design them.

One trouble is that those engineers designed a short term storage facility for the stuff near me. It is only designed to last until it is moved to the long term storage facility. Which was supposed to happen more than a decade ago... You can't get good designs out of engineers when you lie to them.

Thank you kindly.

 

[omgwtfbyobbq]

It does NOT, and the electricity that is consumed is typically from the oil stock itself.

The EPA estimate of ~ 17% energy cost to turn oil into petrol includes all energy inputs. As DGPcolorado said, it really is past time to put that myth to rest.

I don't think electricity is generated from oil. Natural gas is I believe where the vast majority of non-oil energy comes from in terms of extraction/refining. There's a little electricity used from the grid, but the big part is the natural gas used to generate on site electricity/steam for extraction and used to generate Hydrogen for refining.

I also wouldn't characterize it as a myth. IIRC, each gallon of gas not produced (extraction + refining) frees up enough natural gas to generate ~2+kWh of electricity at the national level, and ~5+kWh in states where extraction is energy (aka natural gas) intensive like CA. It's not a huge amount by any stretch, but the ~2kWh-5+kWh of electricity we could generate if we didn't extract/refine gasoline would move an EV ~6-20 miles, which is something.

 

[int32_t]

One trouble is that those engineers designed a short term storage facility for the stuff near me. It is only designed to last until it is moved to the long term storage facility. Which was supposed to happen more than a decade ago... You can't get good designs out of engineers when you lie to them.

Thank you kindly.

That's one of the main issues I have with nuclear. And that's its biggest weakness -- it requires what you can think of a "lifetime support warranty" even after you've forgotten about it. Sometime in the future we'll have a mess of this stuff in our laps with containers past their due date and needing replacement. Then we'll wonder what those idiots in the 21st century were thinking when they went nuclear ...

Even "safe" systems aren't foolproof. But solar is closer to it.

 

[Topher]

Even "safe" systems aren't foolproof. But solar is closer to it.

The worst failure mode for my solar is that it might fall off the roof and kill me. My neighbors should be fine.

Thank you kindly.

 

[int32_t]

Show your math and information sources please.

You are saying it takes refineries (perhaps in Alberta) about 30 kWh of grid electricity to refine one US gallon of gasoline? That's wildly higher than any previous estimate of the energy to refine a gallon of gas. Plus, you think it is all in the form of electricity (made from coal).

I'm rather skeptical.

Unfortunately, this Fully Charged episode Being cited here is almost completely wrong on all of its major points:

1. There is no conspiracy by oil companies to hide their post-2005 grid electricity consumption. The data remains trivially available online from the UN's statistics website.

2. The UN data shows that grid electricity use by UK refineries is between 0.3 - 0.5 kWh per gallon of refined gasoline, not the 4.5 kWh claimed in the episode. This is roughly consistent with US refinery use based on separately published US government statistics.

3. The likely source of this confusion is that refineries use 4.5 - 7.5 kWh of "energy" not "electricity" in refining a gallon of gasoline. Only about 3.5 - 5.5 percent of that energy is in the form of grid electricity. The vast majority of that energy is natural gas and leftover refining byproducts such as so-called "still gas" from earlier refining output. If you stopped refining gasoline, only the natural gas would still be available for charging EVs but would first have to be converted to electricity at 50% efficiency and would translate into about 1.0 - 1.5 kWh of electricity per gallon of gasoline not refined. So, maybe 3 to 6 miles of EV driving rather than 10 to 20.

See my detailed post here:

Pollution: EV vs ICE - Page 3 - My Nissan Leaf Forum

Whoops, I done messed up there. I was going from memory. I did the spreadsheet a little while ago. Blame 2015 me.

The numbers I used were 7.5 kWh (that's the 8 I was referencing) per gallon, or 2 kWh per litre. I'm pretty sure that's electricity, but I can go look and report back. Unfortunately I didn't write down where I got those numbers, but I checked several places on the great wide net before committing to a certain value. My spreadsheet notes say it's a conservative figure. Anyways, the results are unchanged since I just quoted the wrong number and the correct one was used in the spreadsheet all along.

Eh, whatever. I like conspiracy theories.

 

[int32_t]

Speaking of waste energy... It is really sad to see how much natural gas is still being flared off everyday. It is shocking to see when you fly over North Dakota at night.
Is that factored in to the energy required to make gasoline?

I thought that was sour gas, something different. Always thought it would be too easy to stuff it under a boiler and make some steam for electricity production ...

 

[dgpcolorado]

I thought that was sour gas, something different. Always thought it would be too easy to stuff it under a boiler and make some steam for electricity production ...

My understanding is that the oil fields of North Dakota don't have enough pipeline infrastructure, in many locations, to be able to collect and transport that natural gas.

 

[omgwtfbyobbq]

The latest studies tend to show that US refineries are, on average, about 90% efficient overall. Earlier studies tended to show 85-87%.

So, the electricity used in refining a gallon of gas is about 1/20th of the 10% energy loss from refining or somewhere roughly around .05% of the energy in a gallon of gas.

I actually think that is surprisingly good or at least better than I originally expected.

I don't know exactly how or under what regulation the numbers are gathered but I know they are broken out and reported in US government statistics and are also broken out as grid energy used at refineries and reported on a country by country basis in the online UN statistics at data.un.org. If the numbers were just reporting all grid electricity used in a refinery rather than just that used in the refining processes themselves it would, of course, tend to exaggerate the number.

If you look at the link to mynissanleaf.com that I provided a few posts pack on this thread you will see links to the database search pages at data.un.org.

Refinery inputs/efficiency do influence the energy requirements of creating fuels, like gasoline, however the energy inputs for extraction are usually a lot larger.

In CA for instance, extraction alone accounts for ~10% of the state's natural gas consumption.

http://energyalmanac.ca.gov/naturalgas/2013-05-30_California_Natural_Gas.pdf

With ~36 gallons of fuel (Gasoline, Diesel, and Kerosene) per barrel of oil...

History of the 42-Gallon Oil Barrel ·

And 2012 oil production at ~197 million barrels...

California oil and gas industry - Wikipedia, the free encyclopedia

Every gallon of fuel needs ~9kWh of natural gas, just for extraction.

Using that natural gas to generate electricity could provide enough juice to move a Model 3 15+ miles. And that's just the natural gas used for extraction. Add in the electricity used for extraction, the electricity used for refining, the natural gas used for refining, etc... And we could move an EV a decent distance by simply diverting energy from making petroleum based fuels for ICEs to making electricity for EVs.

 

[dhrivnak]

Refineries are complicated in that they use a lot of off products mainly petroleum coke to produce the energy they need. Few power companies would use petroleum coke as a raw material but if you have the choice of using it or paying to dispose of it most refineries will use it. What is harder to dispute that refining does generate a significant amount of CO2. Many models use the stoichiometry balance of 19.6 lbs of CO2/gal of gasoline burned. But if you add in the refining emissions it rises to 23.1 a substantial 17% rise. If you add this in then EV is cleaner than a Prius even in a coal state.


In the petroleum sub-sector (NAICS 324), the petroleum refining industry (NAICS
324110) dominates emission totals, accounting for over 90 percent in 2002, or 277.6 million
metric tons of the 304.8 million metric tons emitted. Of the sources tracked and subsequently
reported by refineries, the largest share of emitted carbon dioxide is from the use of petroleum
– mostly in the form of by-product energy sources such as waste gas (commonly known as still
or refinery gas) and petroleum coke

Gasoline Refining
Energy Information Agency report on CO2 emissions in U.S. Manufacturing
http://www.eia.gov/oiaf/1605/ggrpt/pdf/industry_mecs.pdf
Quantity of gasoline produced - EIA - Petroleum & Other LiquidsManufacturing Refining
U.S. Refinery Utilization and Capacity
Petroleum Refineries
Pg. 6 277,600,000 Metric Tons CO2/year
611,830,400,000 lbs. CO2/yr. Conversion (2204 lbs./MT)
2006 15,600,000 US Refining capacity in barrels/day from website above
30 gal/barrel What Does One Barrel of Crude Oil Make - California Gas Prices
170,820,000,000 Gal/year Convert to gal/year (*30*365)
3.58 lbs. CO2/gal Additional CO2 generated in refining.

 

[Jeff N]

In CA for instance, extraction alone accounts for ~10% of the state's natural gas consumption.

California is not typical. The fields are generally old and have been pumped dry over the decades. All that extraction energy goes towards steam and various techniques to get the very last bit of oil out of the ground. The national average extraction energy is far lower.