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John Petersen bogus article (out of main)
- Thread starter VValleyEV
- Start date
Oh, I didn't add the battery pack embodied emissions for the Camry Hybrid models.
Also, someone else pointed out on SA that MPGe already accounts for charging losses. So no need to add that. Petersen ended up double counting it. So charging off only natural gas peakers still means the Model 3 has less emissions than all the trims of the Camry hybrid. Result is 164 + 36 = 200 g/mile.
Also, on the very day that Petersen chose, April 15, the curtailment of solar and wind was in excess of 3,000 MWh. Charge at work during 11 am and 2 pm and it is as close to zero emissions as possible. Plus, you help CAISO deal with the duck curve which would allow even higher renewable generation to be installed in CA. Similarly, charging at night in Texas and parts of the midwest would allow more wind power to be installed with positive ROI.
Also, someone else pointed out on SA that MPGe already accounts for charging losses. So no need to add that. Petersen ended up double counting it. So charging off only natural gas peakers still means the Model 3 has less emissions than all the trims of the Camry hybrid. Result is 164 + 36 = 200 g/mile.
Also, on the very day that Petersen chose, April 15, the curtailment of solar and wind was in excess of 3,000 MWh. Charge at work during 11 am and 2 pm and it is as close to zero emissions as possible. Plus, you help CAISO deal with the duck curve which would allow even higher renewable generation to be installed in CA. Similarly, charging at night in Texas and parts of the midwest would allow more wind power to be installed with positive ROI.
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bhtooefr
Active Member
As others have pointed out, not the case, it's actually falling into the solar oversupply portion of the duck curve (between behind-the-meter solar and solar power plants). You want to encourage as much workplace charging as possible (while also adding solar capacity to parking to dull the demand increase as well as reducing grid losses), really.
Doggydogworld
Active Member
Do you have a link to GREET results for similar cars?
You claim the average Tesla will be on the road with original pack for 300-500k miles and you call his assumption absurd? 300-500k miles is 30-60 years.
Charger efficiency is already included in his EPA Wh/mile metric. This is his one factual error, which I've pointed out. He's corrected errors in the past, we'll see if he corrects this one.
This is the real issue. We need vastly more EVs to allow vastly higher wind/solar penetration without causing curtailment, grid instability and other problems.
JRP3
Hyperactive Member
Fueleconomy.gov uses the GREET model, so when you compare cars and use the energy and environment tab and choose GHG + upstream, you get the average emissions using the power generation district of your zip code. Petersen chose a good car to compare against, the Camry Hybrid because it gets over 50 mpg. We do need to add the battery impact to the Camry though... that's why I didn't change his numbers from the GREET model to help account for that.
It seems the original link on Daimler's site is now broken. Here's the Green Car Congress article on it:
Mercedes-Benz B-Class Electric Drive reduces lifecycle CO2 emissions by as much as 64% compared to B 180 gasoline model
This is from Mercedes doing a LCA analysis with a Tesla powertrain. The B-class has a 36 kWh pack with the same cells as the original Model S from 2012/2013.
Nope. It's an educated guess based on a few factors. The LCA above uses cells from Panasonic's Suminoe Plant in Osaka which means it has Japanese power production mix. GF1 uses a much cleaner input with mostly natural gas, geothermal, and solar. It is literally within 3 miles of a solar plant and a natural gas plant and it has some solar on the roof. Geothermal plant is not that far away either.
Furthermore, the cathode oven is one of the large energy inputs into the manufacturing process. That alone has a 80% reduction in in energy input as compared to Osaka. There are more parts and pieces, including the chiller, desert air, solvent recovery and recycling system and so forth that reduces the GHG emissions. Furthermore, the cells themselves are 2 steps beyond the original cells in 2012/2013 with higher specific energy and the bigger form factor also helps with less overhead over the active material. Furthermore, the pack level density is much better.
The IVL meta study is actually quite a good compendium:
https://www.ivl.se/download/18.5922...CO2+emissions+from+lithium+ion+batteries+.pdf
If you believe Ellingsen 2014, then cell manufacturing is 61.8% of the GHG emissions. Kim says it's 44.7%. Getting large reduction of energy inputs and having much lower carbon electricity sources means this portion of emissions can drop dramatically. Between all of that, my guess at 90 g/mile is not aggressive.
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We have examples of packs going 300,000 to 500,000 miles. I didn't use that metric, I used 15 years, 200,000 miles for the amortization period.
I've seen him sometimes correct himself, but back in the day, he often didn't. Using EVs to balance the grid or otherwise provide steerable demand is an under appreciated aspect of having a large fleet of EVs. That even helps fossil fuel generation, as plant cycling is a huge issue.
I am still surprised by the CAISO graph that Petersen supplied, if I am reading it correctly. Can someone else comment?
I think it shows highest CO2 emissions, along with highest use of “imported” power, presumably natural gas peak plant production, from about 7pm on through 4am. This seems to support his thesis that charging an EV at night means using the dirtiest power, and that is when they are most often charged. I would have thought that after about 10pm the peak requirements would have been past, and the CO2 emissions dropped to a lower level. Yeah not the lowest because that will be when solar kicks in, but at least would have thought the use of natural gas peak power plant contributions would have been over by midnight.
Or am I reading this thing wrong?
I think it shows highest CO2 emissions, along with highest use of “imported” power, presumably natural gas peak plant production, from about 7pm on through 4am. This seems to support his thesis that charging an EV at night means using the dirtiest power, and that is when they are most often charged. I would have thought that after about 10pm the peak requirements would have been past, and the CO2 emissions dropped to a lower level. Yeah not the lowest because that will be when solar kicks in, but at least would have thought the use of natural gas peak power plant contributions would have been over by midnight.
Or am I reading this thing wrong?
mblakele
FSD Beta (99)
Try California ISO - Emissions — you can set the date on each chart. Peak emissions are right around dawn and dusk. The overnight off-peak period is 23:00-07:00 on the PG&E EV tariff. CO2 emissions in that period aren't as low as in the duck's belly, but they're significantly lower than the crepuscular peaks.
So it's untrue to say that overnight EV charging uses the dirtiest power.
Another point is that power companies also offer guaranteed renewable power. For example I pay an extra penny per kWh for 100% renewable.
JRP3
Hyperactive Member
Petersen wants to assign any ev charging to additional demand which is always supplied by natural gas generated power. Why that applies only to ev demand and nothing else is a mystery, or not.
Try California ISO - Emissions — you can set the date on each chart. Peak emissions are right around dawn and dusk. The overnight off-peak period is 23:00-07:00 on the PG&E EV tariff. CO2 emissions in that period aren't as low as in the duck's belly, but they're significantly lower than the crepuscular peaks.
So it's untrue to say that overnight EV charging uses the dirtiest power.
Another point is that power companies also offer guaranteed renewable power. For example I pay an extra penny per kWh for 100% renewable.
PLEASE help me understand how to read the Petersen graphic, from the same CAISO source on the same day as your example here, and not come to the same conclusion that Petersen does. I find it hard to believe that late night/early morning EV charging coincides with high natural gas peak power, BUT THAT IS WHAT THE CHART SEEMS TO IMPLY.
It seems to show, as he claims, that the late evening and early morning hours are not only those with the highest CO2 emissions (black line), but those with the highest contribution of “imported power” (red diagonal lines), which he claims is natural gas from peak power plants. This is reinforced by the chart to the right, with the green line showing “imports” which he claims means natural gas.
mblakele
FSD Beta (99)
Since that black line for CO2 intensity does not match the CA ISO chart for the same day, I'd guess that Petersen made it up or derived it from less reliable data. Petersen's "data" appears to be less detailed than what CA ISO provides, as well as being wrong. I suspect he either didn't see the CA ISO emissions data, or chose to use his own notion of "carbon intensity" so he could tell a misleading story.
Again, here's the official CA ISO data, which you can set to 2019-04-15 to try and match Petersen:
California ISO - Emissions
Further breakdown by resource, in case it's helpful:
roblab
Active Member
As to pack expected miles: I put on about 30,000 miles a year, which means my car will pass 300K miles in ten years. I don't know about "average", but my miles per year about doubled when I got my Tesla. We also need to remember that there is no required maintenance, ie: Oil Changes and filters. I've never done an oil change on my Teslas, in about 175K miles. That right there saves me over $2000 and the earth more than that. I figure I saved $15,000+ by not having to buy gasoline. These savings allow me to buy Power Walls and solar panels.
I have 11 kW of solar and three Power Wall battery packs. I also charge my cars during the day, during peak, because I generate more that they use. Night usage for my home is easily covered by the Power Walls. I also sell extra generation to the grid so they have less need to burn natgas. Unfortunately, we don't have hydro, but we do get some power from geothermal 20 miles from here, with the rest natgas. But anyone can put in a few solar panels and add to them as able. I've been adding to mine for a good twenty years.
Doggydogworld
Active Member
Well, if we factor in Tesla owners driving twice as many miles as they do in ICE cars the CO2 equation looks really bad
Here's the thing about 300k miles. ICE taxis regularly go 500k miles. Average ICE cars last about 150k miles. It's not the miles, it's the years. New cars are typically garaged, well maintained, repaired under warranty as soon as something breaks, repaired after accidents thanks to good insurance, etc. After several years the owner wants a shiny new toy and the car passes to a second owner and then to a third, who drive it less, maintain it less conscientiously, do minimal out-of-warranty repairs, might only carry liability insurance, etc. They also drive less, so miles accumulate more slowly. By the time a car is 18 years old with 150k on the clock it's sitting in someone's front lawn on the poor side of town, maybe up on blocks waiting for the owner to scrape up cash to replace a broken suspension piece or something. Or it gets damaged in a wreck and isn't worth the cost to repair.
Engines don't really wear out these days, the cars just age out or crash out. It'll be the same with EVs.
JRP3
Hyperactive Member
And the batteries and motors will be sold for other uses since they are rarely damaged in crashes. Already happening. Just because a car may not make it to 300K+ miles doesn't meant the components won't. So that needs to be accounted for in the actual lifetime materials emissions profiles.
Well, if we factor in Tesla owners driving twice as many miles as they do in ICE cars the CO2 equation looks really bad
Here's the thing about 300k miles. ICE taxis regularly go 500k miles. Average ICE cars last about 150k miles. It's not the miles, it's the years. New cars are typically garaged, well maintained, repaired under warranty as soon as something breaks, repaired after accidents thanks to good insurance, etc. After several years the owner wants a shiny new toy and the car passes to a second owner and then to a third, who drive it less, maintain it less conscientiously, do minimal out-of-warranty repairs, might only carry liability insurance, etc. They also drive less, so miles accumulate more slowly. By the time a car is 18 years old with 150k on the clock it's sitting in someone's front lawn on the poor side of town, maybe up on blocks waiting for the owner to scrape up cash to replace a broken suspension piece or something. Or it gets damaged in a wreck and isn't worth the cost to repair.
Engines don't really wear out these days, the cars just age out or crash out. It'll be the same with EVs.
You are using a slew of assumptions here that may not hold true. Most ICE cars get more expensive to operate over time. That may not hold true for a Tesla Model 3. Plus, there are those that have high annual mileage that migrate to Tesla vehicles due to better TCO. I used 15 years, 200,000 miles for my amortization. But for those high mileage folks, 300,000+ can easily be achievable in 10 years and the embodied carbon emissions per mile is substantially less. Furthermore, high mileage drivers may seek out Model 3’s in droves in the used market and therefore the 2nd and 3rd hand owners may very well drive substantially more than average.
smorgasbord
Active Member
Too bad PGE doesn't reduce electricity rates during those hours. They're still "Part Peak", not "Off Peak."
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