EV Effeciency and Carbon Footprint

[R1Sky Business]

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[StormyKnight]

Every time one of these threads pop up I drop in this link:



It is the best, accessible to anyone, discussion on the topic I have found. If you are willing to read the sources and academic papers, you can do better, but this is a really good overview of cradle to grave emissions impact

I just sat down and did the back of the napkin math comparing the cradle to grave CO2 emissions of a Max Pack R1T to a 3.0L turbo diesel Silverado as demonstrated in the video:

R1T: 10 tonnes to produce + 10.8 tonnes to produce battery (low estimate)+ 3.41 tonnes/year to drive 14,000miles using a Michigan electricity mix (from Alternative Fuels Data Center).
Silverado: 10 tonnes to produce + 5.06 tonnes/year

Break even time is around 6.5 years? It's 12.4 years if you use the higher estimates for battery production. This is very surprising and depressing to me! I've always assumed the R1 was the hands down environmental winner but it's not so clear now.

Forgive any math errors! I'm just following the video literally on the back of a napkin.

 

[emoore]

I just sat down and did the back of the napkin math comparing the cradle to grave CO2 emissions of a Max Pack R1T to a 3.0L turbo diesel Silverado as demonstrated in the video:

R1T: 10 tonnes to produce + 10.8 tonnes to produce battery (low estimate)+ 3.41 tonnes/year to drive 14,000miles using a Michigan electricity mix (from Alternative Fuels Data Center).
Silverado: 10 tonnes to produce + 5.06 tonnes/year

Break even time is around 6.5 years? It's 12.4 years if you use the higher estimates for battery production. This is very surprising and depressing to me! I've always assumed the R1 was the hands down environmental winner but it's not so clear now.

Forgive any math errors! I'm just following the video literally on the back of a napkin.

That’s a really high electricity CO2 cost. And that can go to 0 whereas the Silverado can never decrease. Also you didn’t include the CO2 cost of drilling for oil, refining oil to gas, transportation of oil. That’s would be a fair comparison and would mean the break even point is much sooner.

 

[OverZealous]

Also you didn’t include the CO2 cost of drilling for oil, refining oil to gas, transportation of oil. That’s would be a fair comparison and would mean the break even point is much sooner.

That stood out to me in the video, too. I don’t think anyone includes the cost of getting the oil to your vehicle in their estimates.

 

[nc10]

Forgive any math errors! I'm just following the video literally on the back of a napkin.

Interesting. Looked at your numbers briefly, I don't see errors at first glance.

This article was a topic on the site a few weeks ago, went into more detail,
https://iopscience.iop.org/article/10.1088/1748-9326/ac5142

The video narrator indicated he was being conservative when setting the CO2 impact of vehicle construction ex battery, ICE vs EV, to be the same. The estimate in this article indicated a "with battery" construction difference of about 7 mt CO2, so a shorter time to offset the construction cost. It would be interesting to know what the actual error bars are, probably depends on where the batteries are constructed, type of Li mine, etc.

I wasn't really aware of the diesel vs gas difference, diesel CO2 emissions are a lower than equivalent gasoline CO2 emissions, but historically NOx's, SOx's particulates were worse. I expect a new silverado diesel compares better though.

MIchigan apparently is a little worse than the national average as far GHG emissions from electricity, would be interesting to see how that is expected to change going forward, and if there are advantages if you only charge off peak hours. On the other hand, most of these studies are ignoring the phantom losses that Rivian forum members are seeing with their new R1T's.

 

[emoore]

Hopefully by 2035 the entire grid will be renewable.

 

[Craigins]

MIchigan apparently is a little worse than the national average as far GHG emissions from electricity,

States are not their own grid (aside from Texas). That's not how it works.

 

[ajdelange]

States are not their own grid (aside from Texas). That's not how it works.

True but each utility knows from whom it buys its electricity and thus for each state we can do a weighted sum over its utilities to determine the average carbon burden for that state. Is there any doubt that West Virginia that obtains most if its electricity from coal burning plants within the state is dirtier than, say, New York who buys a lot from Quebec Hydro?

 

[Craigins]

True but each utility knows from whom it buys its electricity and thus for each state we can do weighted sums over each utility to determine the average carbon burden of each. Is there any doubt that West Virginia that obtains most if its electricity from coal burning plants within the state is dirtier than, say, New York who buys a lot from Quebec Hydro?

The grid is energized by generators. You do not buy power from specific plants.

What you describe is a financial function, not a physics function. I.e. you pay the generator to supply energy to the grid. That doesn't mean your utility is using that electricity.

 

[zipzag]

The carbon characteristics of a local large utility is a good way to look at how green you are fueling your EV. Also looking at the probable mix at the time you charge. Rates in NE Illinois are low overnight due to a high percentage of nuclear. On a sunny reasonably cool day in Socal you are mostly charging off solar.

 

[ajdelange]

What you describe is a financial function, not a physics function. I.e. you pay the generator to supply energy to the grid. That doesn't mean your utility is using that electricity.

There is some truth to what you say when it comes to those REC scams (I shouldn't take that tone - I make about $700/yr selling them) whereby the tree huggers can claim they use only green electricity because they buy RECs but there is physics involved too. You can quickly see this by constructing, on your computer a simple network. Analysis shows that MOST of the power you get comes from the closest sources. thus where does my arch conservative, damn the tree huggers neighbor get most of his electricity on a sunny day? My solar panels. My excess generation does NOT go back to the utility. It goes straight into my closest neighbors houses. Similarly, while it is true that I would get a tiny, tiny amount of power from each coal burning plant in West Virginia (I am in Virginia) that amount is trivial compared to what I get from closer sources. Thus my statements are valid - not to the fraction of a percent but to a percent or so. When I am charging in VA (from the utility) my electricity is about 30% clean. When i am charging in Quebec it's 100% clean.

 

[nc10]

States are not their own grid (aside from Texas). That's not how it works

OK. Sigh...... The "easily referenced" data we have showing GHG emissions from electrical supply is documented, tracked and sorted by state, and that is the kind of data often used in high level (ie ballpark) calculations. I agree, you can get more specific and accurate info for a specific case. The state level data is useful, but not perfect. Sorry for going forward with the simplification.

I expect the OP could get a better estimate from his utility company, but I was 99% sure he used the state level GHG data in his initial calculation. Certainly using state level GHG data was referenced in the video. If watch the video, the calculations were pretty high level, and there were a lot of simplifications you could find fault with, if you want. Electricity generation doesnt' fit neatly into state borderlines, prob even less so for incremental supply.

For example
https://www.statista.com/statistics...dioxide-emission-rate-by-state-united-states/

From the video, state level data source for GHG emissions.

 

[ads75]

States are not their own grid (aside from Texas). That's not how it works.

But states can and do have their own power plant emission requirements. That's one reason on some state borders you can see a few power plants on one side of a border and not the other. The electricity all gets fed into the same grid (for the most part), and the emissions essentially the same place, but different states have different emission or water requirements in addition to any federal requirements. Let's say the City of Los Angeles owns a power plant in Utah, the emissions probably go into Utah's calculations, even though the "customer" is in California.
https://www.latimes.com/business/la-fi-utah-coal-los-angeles-climate-20190711-story.html

 

[StormyKnight]

I wanted to run a little further with this exercise. More back of the napkin math and random thoughts...

Our local utility purchases all of the power it distributes so the numbers for Michigan from the Alternative Fuels Data Center match relatively closely. We have a slightly higher percentage of electricity generated from NG instead of coal so our GHG emissions are slightly lower than the Michigan average but it is pretty close.

We are a very rural community. I took a closer look at my odometer from service visits and also calculated out several days of routes and highway versus city driving. I drive further than I estimated with more highway miles than originally estimated.

R1T: 10 tonnes to produce + 10.8 tonnes to produce battery (low estimate)+ 3.27 tonnes/year to drive 14,192 miles using a Michigan electricity mix (from Alpena Power website).
Silverado: 10 tonnes to produce + 5.62 tonnes/year

Break even point is a little better at 4 years and 7 months.

-------------------------------------

One more step:

A nicely equipped Silverado is priced at $56,026 (currently at our local dealer) which is almost $30,000 less than my configured R1T. If I try to offset Silverado GHG emissions with a 5 KWh solar array (also around $30K?) this could offset 2.87 tonnes of CO2 emissions. This data is from my own current 20KWh array and emission numbers from an equivalent amount of electricity from Alpena Power. In this scenario, there is no break even. I understand that the best scenario is the R1 plus solar but I am already stretching the budget and do not see this as financially feasible.

There have been a couple of mentions about the environmental cost of extracting, processing and shipping diesel fuel but there is also a cost for doing the same with coal and NG. It may be beneficial to try to tap into these differences in the future.

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