The CO2 emissions for a Toyota Camry Hybrid are simple to calculate. According to the U.S. Energy Information Agency, burning a gallon of gas produces 8,890 grams of CO2.
Anyone checked this? I never heard of this Agency
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The CO2 emissions for a Toyota Camry Hybrid are simple to calculate. According to the U.S. Energy Information Agency, burning a gallon of gas produces 8,890 grams of CO2.
Those who charge at work would more likely be the ones that fall into the gas powering because that's during peak times. (Another reason why I'm not a big fan of workplace charging. Ducks, and not from the duck curve.)
Do you have a link to GREET results for similar cars?First, he doesn't start with the GREET model.
The result is that the B-class electric, with a 36 kWh battery pack, had 4.6 metric tons more emissions than the B 180 diesel vehicle. Which means the battery pack contributed no more than 4.6 metric tons assuming an even trade between the engine parts and the rest of the electric drivetrain. That's 128 kg/kWh of GHG emissions. Petersen went with 170 kg/kWh.
The real figure now is likely closer to 90 kg per kWh.
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.He also makes an assumption of 12 years, 150,000 miles before pack replacement. That's absurd. Pack replacement on average likely is at 300,000 to 500,000 miles.
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.Furthermore, charging efficiency has been shown to be between 85% and 92% depending on the EVSE.
Now, back to CA. Obviously, charging off solar during the day is best. That can actually help out the duck curve. What is really interesting is the oversupply situation:
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.California ISO - Managing Oversupply
In other words, there are times when CA has too much renewable supply and has to curtail wind and solar production. Charging your car during 11am and 2pm means CA needs to curtail solar and wind less! That's about as close to zero emissions as possible.
Or not. @TeslaMilesYou 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.
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.
Do you have a link to GREET results for similar cars?
There are a lot of detailed academic studies out there with a lot of numbers. 170 is neither the highest nor the lowest I've seen. Company-paid studies carry less weight, but if you have a link to the actual study I'd like to check it out. It seems GreenCar once had a link, but it's busted.
You just made this up.
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.
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?
View attachment 398211
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.
View attachment 398523
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.
Well, if we factor in Tesla owners driving twice as many miles as they do in ICE cars the CO2 equation looks really bad... my miles per year about doubled when I got my Tesla.
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.
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.
Charging your car during 11am and 2pm means CA needs to curtail solar and wind less! That's about as close to zero emissions as possible.