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Thanks for the reply. It will take a bit of time to completely digest it. Proper usage is indeed very important. Not doing so is like buying a heavy-duty reusable plastic shopping bag but never actually reusing it, making it significantly worse. But, a good question is: What is the effective mpg of a PHEV as typically driven? If the PWN efficiency requirement of > 95 mpg is accepted, which is the highest in the U.S. and likely anywhere, then how much must a Volt be driven as an EV to break even? A Volt gets ~42 mpg in hybrid mode. So, EV mode %0 + Hybrid mode 100% = 42 mpg. If 50% of the driving was in in EV mode, total mpg = 82 mpg. But, using your figures, if 66.5% of driving is in EV mode, then the total mpg = 125 mpg. With a little math, the breakeven point of 95 mpg is achieved with just 56% of EV-mode driving. This makes a Volt as typically driven much better than a BEV even in the PNW, and far better anywhere else in the country. Much of the country will require a far smaller percent of EV-mode driving. So by these calculations, a PHEV with similar characteristics as a Volt, typically driven, is the clear winner. I would say that for BEV owners who are good at plugging in, a PHEV would be even better as they would be driving even more in EV mode. But each person will do best to modify that for their particular situation. Those with long commutes, meaning a low percentage of EV-mode driving, will certainly do better with a BEV, as will those who use a PHEV as just a hybrid. As for your specific situation, if you leave home with a full battery and are able to recharge to full at work, then your EV-mode percentage would be 61.5%, which would make a PHEV better even if you lived in the PNW. If you live elsewhere, then the threshold would be even lower.
You can't do the math like this. When I get home I can work out the math to compare a PHEV to a BEV. I teach physics so trust me on this one that you can't do the math you just did.
 
I've maintained that manufacturers would have been smart to max out the federal tax credit using PHEVs that have the minimum size battery to claim the full credit, which is 16 kWh. The battery would then be subsidized by taxpayers at $469 per kWh, which is far above the cost to manufacture. That's money on the table.
That's exactly what Toyota is doing. 2020 RAV4 Prime (PHEV) will have $7500 tax credit. When I was looking at the Prius Prime, it would be cheaper than the Prius, after the $500 tax credit. RAV4 should be similar.
 
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I look forward to your calculations, but if you could also explain a bit how I have miscalculated, I would appreceate that too.
Your calculations assume that the electricity has no CO2 impact. A 42 mpg car running at 84 mpg with 50% electricity makes no sense. By your calculations a BEV should get infinity mpg.

Edit: you need to take MPGe into consideration. Please read up on MPGe.
 
I look forward to your calculations, but if you could also explain a bit how I have miscalculated, I would appreceate that too.
BTW, my calculations will include CO2 emissions when the battery is made. Do you know that driving on pure electricity the Bolt gets more mileage? It is more efficient to drive a Bolt over a Volt. The Volt weighs more than the Bolt by 200 lbs.
 
That's exactly what Toyota is doing. 2020 RAV4 Prime (PHEV) will have $7500 tax credit. When I was looking at the Prius Prime, it would be cheaper than the Prius, after the $500 tax credit. RAV4 should be similar.
According to Fueleconomy.gov, the plug-in Prius had a $2,500 credit, and the Prius Prime has $4,500. In my view, that's leaving a lot of money on the table, but perhaps in the grand scheme of things, the few thousand extra per vehicle isn't worth it to Toyota. They have burned through over half their credit allotment with zero vehicles claiming the full amount. My estimate is they have forfeited $375M in free money by selling 100k vehicles at roughly half the credit limit.

I expect the RAV4 Prime to be a wild success given the desirability of the vehicle in general, and considering it will likely be less costly after rebate than the non plug-in version.

That was my point though, that any manufacturer could have had a plug in version of their most popular vehicles cost less to consumers than their non plug-in versions after the federal credit was factored in.

PHEV is the gateway drug to BEVs. Not only could manufacturers stand to profit from our ridiculous tax incentive(s), but they could be exposing a larger portion of the population to the joy of less visits to the petrol station and all the other benefits of EV driving.
 
You guys could come up with the perfect plug-in hybrid, but I wouldn't buy one. I considered and skipped getting first the Prius and then the Volt. Waited instead for a pure electric. Now maybe a 48V mild hybrid makes sense. Stop all that idling and recover some braking energy.
 
I look forward to your calculations, but if you could also explain a bit how I have miscalculated, I would appreceate that too.
Gas and electricity are not equivalent. Electric motors are much more efficient than gas engines. A car that gets 42 MPG on gas goes alot farther on an equivalent amount of electrical energy. The EPA tries to make these equivalent using the metric MPGe, which is the electrical equivalent to MPG. Essentially it's the mileage on 33.7 kWh of energy, which is considered the equivalent of one gallon of gas.

So for example if a PHEV got 42 MPG on gas and 96 MPGE electric and had a 33.6 kW battery, then it would travel 96 miles in electric mode using 33.7 kWh and 42 miles on a gallon of gas.

ga2500ev
 
Your calculations assume that the electricity has no CO2 impact. A 42 mpg car running at 84 mpg with 50% electricity makes no sense. By your calculations a BEV should get infinity mpg.

Edit: you need to take MPGe into consideration. Please read up on MPGe.

BTW, my calculations will include CO2 emissions when the battery is made. Do you know that driving on pure electricity the Bolt gets more mileage? It is more efficient to drive a Bolt over a Volt. The Volt weighs more than the Bolt by 200 lbs.
I think my method gives a good first order approximation of relative CO2 costs which is likely to hold true unless the CO2 cost of a BEV and PHEV are very close. In such a case a more refined calculation could tip the scales the other way. But, we can do other calculations that might give more insight. So, lets use a Bolt and a Volt for comparison. To do this, I will calculate the CO2 cost of traveling 100 miles in both vehicles. I will make this calculation for Oregon, which is where I live and which has a very low carbon intensity for electricity generation.

A few baseline notes:

A lithium-ion car battery has a life cycle CO2 cost of about 1.5 g CO2 / kwh / km. (1)
The Bolt has a 60 kWh battery, so the CO2 cost is ~ 1.5g CO2 / kWh * 60 kWh / km * 1 km / 0.62 mi = 145 g CO2 / mi. = 0.145 kg / mi.
The Volt has a 16 kWh battery, so the CO2 cost is ~ 1.5g CO2/kWh * 16 kWh / km * 1 km / 0.62 mi = 38.7 g CO2 / mi = 0.0387 kg / mi.

The Bolt has an MPGe of 119, or 28 kWh / 100 miles.
The Volt has an MPGe of 106, or 31 kWh / 100 miles.

For Oregon, the carbon intensity of electricity is ~ 0.11 kg / kWh. (2)

Bolt CO2 / 100 miles: 28 kWh / 100 mi * 0.11 kg / kWh + 0.145 kg / mi * 100 mi = 17.6 kg / 100 miles.

Volt CO2 /100 miles
: I'm using your typical use of 66.5% EV mode. So, the Volt will travel 66.5 miles in EV mode and 33.5 miles in hybrid mode. EV mode CO2 cost is 31 kWh / 100 miles or 20.615 kWh / 66.5 miles * 0.11 kg CO2 / kWh = 2.26 kg CO2 / 66.5 miles for the electricity. The life-cycle battery cost is 100 mi *0.0387 kg / mi =3.87 kg. Then there will be 33.5 miles of hybrid mode at 42 miles / gal. So 33.5 miles / 42 mpg = ~0.8 gallons. 1 gal = 8.9 kg CO2 (3). so 33.5 miles produces 0.8 g * 8.9 kg = 7.12 kg CO2 / 33.5 miles. Total CO2 cost of 100 miles = 2.26 kg + 3.87 kg+ 7.12 kg = 13.25 kg / 100 miles.

In summary: CO2 cost of traveling 100 miles is 17.6 kg CO2 for the Bolt and 13.25 kg CO2 for the Volt.

Clearly, the Volt has a much smaller CO2 footprint that the Bolt. Furthermore, this is for Oregon which has low carbon intensity electricity. The typical state has 5 times the carbon intensity of electricity of Oregon, so almost anywhere else will even more heavily favor the Volt.

We could take this one step further. Suppose that the carbon cost of electricity is 0, as is was at least at one time in Vermont. Let's also suppose that the life-cycle battery cost is only 1 g CO2 / kWh / km, the low end of the range in my reference (1). With these numbers, the Bolt CO2 cost is ~9.7 kg / 100 miles, but the Volt CO2 cost is also 9.7 kg CO2 / 100 miles. So in the best-case scenario, the Volt is still as good as the Bolt.

Hence, I think I can continue to keep the position that a good PHEV properly used is more environmentally friendly that a BEV and will remain so until the carbon intensity of manufacturing falls greatly. But, this still might not hold for an urban BEV: subcompact with a small battery giving 70 miles of range or less.

This does not take into account the manufacturing CO2 costs of producing the rest of each car, but I doubt that it would make much of a real difference, especially since the Bolt lags badly.

(1) Green Car Congress: "ICCT assesses impact of EV battery manufacturing life-cycle emissions debt; policy implications"
(2) Energy Vangard: "How Dirty Is Your State's Electricity?" Graphic with references.
(3) EPA: Greenhouse Gas Equivalencies Calculator
 
I think the whole "charge by time spent" is related to DCFC hoggers who keep the stations occupied when they dont need to. But I didn't read the whole package... so maybe I am wrong.
 
A lithium-ion car battery has a life cycle CO2 cost of about 1.5 g CO2 / kwh / km. (1)
This is what I don't agree with and is a ridiculous number. Right now the accepted value for CO2 emissions is somewhere between 70 and 110 kg of CO2 per 1 kWh of battery. I will use the worse case of 110 kg per kWh in my calculation below. The 150 to 200 kg of CO2 per kWh of battery is old data that suggests the battery is made 100% from coal power. Tesla is probably somewhere between 80 and 90 kg of CO2 per 1 kWh of battery since they use Nevada's energy grid, which is much better than pure coal.

Lets take a look at that 1.5 g CO2 / kWh / km number you used. I have seen this before an it is based on the lifetime of the battery which is 10 years/150,000 km. BTW, this lifetime is nonsense because it takes into consideration only 93,000 miles before you discard the battery. The true lifetime of a Chevy Bolt battery could be 300,000 miles and then could be used for battery storage after that. So for 1.5 g CO2 / kWh / km number you used for 150,000 km, that is 225 kg of CO2, which is not even in the ballpark for the real amount of CO2 that is produced. Welcome FUD from German research trying to keep their diesel cars looking better.

I completely disagree with your calculations since you are assuming a battery is only used for 150,000 km, the battery uses 225 kg of CO2 to be produced, and that 8.9 kg of CO2 per gallon of gasoline is also not correct. That 8.9 kg of CO2 is only the combustion of gas and doesn't include extracting, refining, and transportation. The CO2 number for the battery includes mining, transportation, and manufacturing so we need to be consistent. The best number for gasoline is somewhere between 11 and 12 kg of CO2 per gallon of gasoline. I will use 11 kg in my calculation for the low estimate in the favor of the Volt. I also don't like your carbon intensity data since it is from 2012. Lots of things happened between that data and today in the US, for the good!

Here is a 100,000 mile and 200,000 mile calculation that is realistic. I am not going to do per 100 miles since I need to calculate when the battery will die. I can't predict that number. BTW, this is a worse case scenario since the batteries are not out of service at 100,000 miles or even 200,000 miles.

Bolt for 100,000 miles - 110 kg * 60 kWh + 0.11 * 100,000 = 17,600 kg
Bolt for 200,000 miles - 110 kg * 60 kWh + 0.11 * 200,000 = 28,600 kg

Volt for 100,000 miles - 110 kg * 16 kWh + 0.11 * 66,500 + 11*(33,500/42) = 17,848 kg
Volt for 200,000 miles - 110 kg * 16 kWh + 0.11 * 133,000 + 11*(67,000/42) = 33,398 kg

I gave the Volt the advantage in my consideration in both the battery and the gasoline emissions. I could have made the difference even bigger. I think the 66.5% calculation is fair for the Volt. The Volt also has to get oil changes and produces local emissions. However, a case can be made for a PHEV over a BEV if you take into consideration mileage driven and also if you can drive a PHEV over 90% electric it may be the better choice.
 
This is what I don't agree with and is a ridiculous number. Right now the accepted value for CO2 emissions is somewhere between 70 and 110 kg of CO2 per 1 kWh of battery. I will use the worse case of 110 kg per kWh in my calculation below. The 150 to 200 kg of CO2 per kWh of battery is old data that suggests the battery is made 100% from coal power. Tesla is probably somewhere between 80 and 90 kg of CO2 per 1 kWh of battery since they use Nevada's energy grid, which is much better than pure coal.

Lets take a look at that 1.5 g CO2 / kWh / km number you used. I have seen this before an it is based on the lifetime of the battery which is 10 years/150,000 km. BTW, this lifetime is nonsense because it takes into consideration only 93,000 miles before you discard the battery. The true lifetime of a Chevy Bolt battery could be 300,000 miles and then could be used for battery storage after that. So for 1.5 g CO2 / kWh / km number you used for 150,000 km, that is 225 kg of CO2, which is not even in the ballpark for the real amount of CO2 that is produced. Welcome FUD from German research trying to keep their diesel cars looking better.

I completely disagree with your calculations since you are assuming a battery is only used for 150,000 km, the battery uses 225 kg of CO2 to be produced, and that 8.9 kg of CO2 per gallon of gasoline is also not correct. That 8.9 kg of CO2 is only the combustion of gas and doesn't include extracting, refining, and transportation. The CO2 number for the battery includes mining, transportation, and manufacturing so we need to be consistent. The best number for gasoline is somewhere between 11 and 12 kg of CO2 per gallon of gasoline. I will use 11 kg in my calculation for the low estimate in the favor of the Volt. I also don't like your carbon intensity data since it is from 2012. Lots of things happened between that data and today in the US, for the good!

Here is a 100,000 mile and 200,000 mile calculation that is realistic. I am not going to do per 100 miles since I need to calculate when the battery will die. I can't predict that number. BTW, this is a worse case scenario since the batteries are not out of service at 100,000 miles or even 200,000 miles.

Bolt for 100,000 miles - 110 kg * 60 kWh + 0.11 * 100,000 = 17,600 kg
Bolt for 200,000 miles - 110 kg * 60 kWh + 0.11 * 200,000 = 28,600 kg

Volt for 100,000 miles - 110 kg * 16 kWh + 0.11 * 66,500 + 11*(33,500/42) = 17,848 kg
Volt for 200,000 miles - 110 kg * 16 kWh + 0.11 * 133,000 + 11*(67,000/42) = 33,398 kg

I gave the Volt the advantage in my consideration in both the battery and the gasoline emissions. I could have made the difference even bigger. I think the 66.5% calculation is fair for the Volt. The Volt also has to get oil changes and produces local emissions. However, a case can be made for a PHEV over a BEV if you take into consideration mileage driven and also if you can drive a PHEV over 90% electric it may be the better choice.
I'll look into your points further, but here are some quick points:

The numbers for the life-cycle CO2 cost of battery production come from work by Hall and Lutsey (2018). I'm not sure where they get their numbers, but it was a recent investigation. The range of values is 1 – 2 g CO2 / kWh / km. I chose 1.5 g as the midrange value. Their study is referenced in many recent reports, so you'll have to demonstrate that those figures are not correct. If you have truly new data, please share the reference. Furthermore, I gave a best-case (for the Bolt) scenario where I used the 1 g figure; it still didn't look good. Labeling data you don't like as “FUD” is disingenuous.

The Chevy Bolt battery pack is made in Michigan, not a state with the cleanest electricity. Cherry picking data by referring to Tesla's battery and implying that value should apply to all BEVs is not useful.

Your value of 225 kg CO2 for 150,000 km is not correct. 1.5g CO2 / kWh / km* 60 kWh * 150,00 km * 1 kg / 1000 g = 13,500 kg CO2.

The CO2 cost to refine 1 gallon of gas is roughly 1 kg. (http://www.afteroilev.com/Pub/CO2_Emissions_from_Refining_Gasoline.pdf) Please share a different reference if you don't like this one. That makes the total CO2 cost of 1 gallon of gas 9.9 kg / CO2, and the Volt CO2 cost for 33.5 hybrid miles is 7.92 kg. That increases the Volt CO2 cost by only ~ 0.8 kg CO2, far less than needed to overcome the Bolt's poorer numbers. Admittedly, this doesn't include CO2 associated with exploration, drilling, pumping and transport. Still, I doubt that taking that into account could overcome the roughly 2.5 kg CO2 / 100 mile deficit of the Bolt.

Changes to the electrical grid have been encouraging but pretty marginal, not nearly enough to overcome the Bolt's poor number, especially since I included a scenario which assume 0 CO2 electricity cost for propulsion.

I don't think you have made your case. It appears to me you are struggling to come up with numbers that just evens the score, much less showing a significant advantage for BEVs.
 
I'll look into your points further, but here are some quick points:

The numbers for the life-cycle CO2 cost of battery production come from work by Hall and Lutsey (2018). I'm not sure where they get their numbers, but it was a recent investigation. The range of values is 1 – 2 g CO2 / kWh / km. I chose 1.5 g as the midrange value. Their study is referenced in many recent reports, so you'll have to demonstrate that those figures are not correct. If you have truly new data, please share the reference. Furthermore, I gave a best-case (for the Bolt) scenario where I used the 1 g figure; it still didn't look good. Labeling data you don't like as “FUD” is disingenuous.

The Chevy Bolt battery pack is made in Michigan, not a state with the cleanest electricity. Cherry picking data by referring to Tesla's battery and implying that value should apply to all BEVs is not useful.

Your value of 225 kg CO2 for 150,000 km is not correct. 1.5g CO2 / kWh / km* 60 kWh * 150,00 km * 1 kg / 1000 g = 13,500 kg CO2.

The CO2 cost to refine 1 gallon of gas is roughly 1 kg. (http://www.afteroilev.com/Pub/CO2_Emissions_from_Refining_Gasoline.pdf) Please share a different reference if you don't like this one. That makes the total CO2 cost of 1 gallon of gas 9.9 kg / CO2, and the Volt CO2 cost for 33.5 hybrid miles is 7.92 kg. That increases the Volt CO2 cost by only ~ 0.8 kg CO2, far less than needed to overcome the Bolt's poorer numbers.

Changes to the electrical grid have been encouraging but pretty marginal, not nearly enough to overcome the Bolt's poor number, especially since I included a scenario which assume 0 CO2 electricity cost for propulsion.

I don't think you have made your case.
1 – 2 g CO2 / kWh / km is absolutely insane. That is considering 150,000 km of lifetime use and batteries shown they can be used much longer than that. In matter of fact you can use them after the car is done by taking the batteries and using them as solar energy batteries. Below is an article that you can read that shows that the number that Hall and Lutsey, which they reference, is way too high!
Please read the article to see that the 225 kg CO2 for 1 kWh of a lithium ion battery is nonsense.

Your value of 225 kg CO2 for 150,000 km is not correct. 1.5g CO2 / kWh / km* 60 kWh * 150,00 km * 1 kg / 1000 g = 13,500 kg CO2.
That 225 kg CO2 is for 1 kWh of battery produced. I didn't calculate it for the Bolt since that number is freaking insane.

The CO2 cost to refine 1 gallon of gas is roughly 1 kg.
That is correct. But what about drilling and transporting the oil? That is another 1 to 2 kg. I think you can agree with that.

I am not using the 1-2 g CO2 / kWh / km that assumes 150,000 km of useful life of a lithium ion battery. The useful life of a lithium ion battery is probably closer to 300,000 miles of use. Plus the bigger Bolt battery will have a longer life than a Volt battery because of the reduced charging cycles.

Please read that article I posted since it talks about many different studies on CO2 emissions from producing a battery.

The Chevy Bolt battery pack is made in Michigan, not a state with the cleanest electricity. Cherry picking data by referring to Tesla's battery and implying that value should apply to all BEVs is not useful.
The batteries for the Bolt are not made in Michigan, it is LG chem which has their factories in Korea. The data in the paper shows the Tesla is the lowest because of Nevada's energy production, but the 110 kg CO2 according to the many studies is a fair number to use for Korea's energy grid.
 
1 – 2 g CO2 / kWh / km is absolutely insane. That is considering 150,000 km of lifetime use and batteries shown they can be used much longer than that. In matter of fact you can use them after the car is done by taking the batteries and using them as solar energy batteries. Below is an article that you can read that shows that the number that Hall and Lutsey, which they reference, is way too high!
Please read the article to see that the 225 kg CO2 for 1 kWh of a lithium ion battery is nonsense.

Your value of 225 kg CO2 for 150,000 km is not correct. 1.5g CO2 / kWh / km* 60 kWh * 150,00 km * 1 kg / 1000 g = 13,500 kg CO2.
That 225 kg CO2 is for 1 kWh of battery produced. I didn't calculate it for the Bolt since that number is freaking insane.

The CO2 cost to refine 1 gallon of gas is roughly 1 kg.
That is correct. But what about drilling and transporting the oil? That is another 1 to 2 kg. I think you can agree with that.

I am not using the 1-2 g CO2 / kWh / km that assumes 150,000 km of useful life of a lithium ion battery. The useful life of a lithium ion battery is probably closer to 300,000 miles of use. Plus the bigger Bolt battery will have a longer life than a Volt battery because of the reduced charging cycles.

Please read that article I posted since it talks about many different studies on CO2 emissions from producing a battery.

The Chevy Bolt battery pack is made in Michigan, not a state with the cleanest electricity. Cherry picking data by referring to Tesla's battery and implying that value should apply to all BEVs is not useful.
The batteries for the Bolt are not made in Michigan, it is LG chem which has their factories in Korea. The data in the paper shows the Tesla is the lowest because of Nevada's energy production, but the 110 kg CO2 according to the many studies is a fair number to use for Korea's energy grid.
Thanks for the follow up and the reference. It might take a couple of days for me to investigate your post. But, from your reference, I think the following quote refering to the Tesla Model 3 is interesting:

"It still has lifetime emissions similar to the most efficient conventional cars in Germany and the US, but is, in all cases, a substantial improvement over the average conventional vehicle."

Given that a PHEV is far better than even an efficient conventional car, it would still appear that the PHEV wins over the BEV. This doesn't immediately look good for your position. I also don't think it is appropriate to rely on post-life-cycle possible uses to make up for a BEV deficit. If BEVs are clearly superior, it would not be necessary. I will explore these things further and modify my position if warranted, but it doesn't look promising even from your referenced source. But, give me a bit of time.
 
Thanks for the follow up and the reference. It might take a couple of days for me to investigate your post. But, from your reference, I think the following quote refering to the Tesla Model 3 is interesting:

"It still has lifetime emissions similar to the most efficient conventional cars in Germany and the US, but is, in all cases, a substantial improvement over the average conventional vehicle."

Given that a PHEV is far better than even an efficient conventional car, it would still appear that the PHEV wins over the BEV. This doesn't immediately look good for your position. I also don't think it is appropriate to rely on post-life-cycle possible uses to make up for a BEV deficit. If BEVs are clearly superior, it would not be necessary. I will explore these things further and modify my position if warranted, but it doesn't look promising even from your referenced source. But, give me a bit of time.
For heavy use a BEV is superior, but people don't drive like me. I put 40,000 miles on my car every year. The longer you drive a BEV, the better it gets. In my situation a BEV is superior considering I drive in California, have solar panels, and have a 130 mile commute every day. For me a BEV is much better for the environment than a PHEV, please prove me wrong about my situation.

Even if PHEV are more "green" right now, that won't be the case in 10 years. By pushing BEV technology, we will have a point where they will become better very soon. If we can produce a lithium ion battery with 50 kg of CO2 per kWh and the battery can last 1 million miles, BEV's will be superior in every way! Part of me adopting a pure EV is that I want this technology to win.

The other thing that is important to know is every year my BEV produces less emissions as the power grid becomes more renewable. This is not true of PHEV's since they always depend on fossil fuels. My argument right now is a PHEV like the Volt and BEV are probably about the same for the environment. I am not saying all PHEV's because they are making SUV one's that get like 15 mile range, 30 mpg, and will rely on 70% of the energy to be gas.

Just answer my question here. Would you agree that if we got battery emissions down to 70 kg per kWh and 70% of energy was renewable that a BEV would be superior to a PHEV? I know we aren't there yet, but that is the goal. We hit limits on ICE cars and hybrid technology. To take the next step in reducing CO2 we need to invest in BEV technology more.
 
For heavy use a BEV is superior, but people don't drive like me. I put 40,000 miles on my car every year. The longer you drive a BEV, the better it gets. In my situation a BEV is superior considering I drive in California, have solar panels, and have a 130 mile commute every day. For me a BEV is much better for the environment than a PHEV, please prove me wrong about my situation.

I think my calculations already prove you wrong, but again, I will look further and perhaps try your approach to see what I come up with. Always, everyone needs to modify basic approaches for their particular situation. However, I offered a scenario with 0 CO2 cost of electricity, and the BEV still wasn't a clear-cut winner. Perhaps that calculation will change as I look further, but I think it is basically sound. Assuming after-life-cycle amelioration shouldn't be necessary. Even in your own "heavy use" case, if you can charge at work, then you still would operate 61% of the time as an EV, and that would increase when considering around-town uses. It is true that at some point a BEV will likely be better, though never in the Midwest.

Even if PHEV are more "green" right now, that won't be the case in 10 years. By pushing BEV technology, we will have a point where they will become better very soon. If we can produce a lithium ion battery with 50 kg of CO2 per kWh and the battery can last 1 million miles, BEV's will be superior in every way! Part of me adopting a pure EV is that I want this technology to win.

I look forward to the day when manufacturing is carbon neutral. That will change many things. But, even in 2040, the world will still be getting most of its energy from fossil fuels, more than 70%. The U.S. might do a bit better, but maybe not, and I am not confident that it will be so. Still, people must make choices now, not for what might be in 10 years. Right now, and for years to come, I have no reason to think that a PHEV isn't the best choice.

The other thing that is important to know is every year my BEV produces less emissions as the power grid becomes more renewable. This is not true of PHEV's since they always depend on fossil fuels. My argument right now is a PHEV like the Volt and BEV are probably about the same for the environment. I am not saying all PHEV's because they are making SUV one's that get like 15 mile range, 30 mpg, and will rely on 70% of the energy to be gas.

Yes, for sure. The faster we decarbonize the better. But decarbonization does help a PHEV because 2/3 or more of the time it operates as an EV. But, it is unlikely that states will become less carbon intensive than Oregon. Using Oregon was my attempt to be as favorable to BEVs as possible. Most states have far to go to get where we are. And, even in Oregon, it appears that a PHEV is a clear winner. I know that you don't like my calculation, and I'll look into that further. But right now I think it is basically sound. Any modification isn't likely to be much more than a rounding error. I agree that PHEV SUVs need to improve. But, the RAV4 Prime gets 40 mpg combined in hybrid mode, and I believe the battery is big enough for 40 miles of EV travel. That puts it fairly close to the Volt. The MPGe is only 90, but not enough of a difference to likely tip the scales. I didn't buy a Prius Prime because of the short battery range, and I didn't want a sedan. I also passed on the Outlander PHEV because of the rather poor MPG rating and short range. But a new generation will be available very soon which changes the calculus. I feel confident speculating that the RAV4 Prime is superior to a BEV in total CO2 emissions as well as offering an overall more compelling package.

Just answer my question here. Would you agree that if we got battery emissions down to 70 kg per kWh and 70% of energy was renewable that a BEV would be superior to a PHEV? I know we aren't there yet, but that is the goal. We hit limits on ICE cars and hybrid technology. To take the next step in reducing CO2 we need to invest in BEV technology more.

Well, it depends on the carbon footprint of manufacturing, which is what I guess you are referring to. I would have to run some numbers to determine what the breakeven point would be. Assuming can be a dangerous activity. But clearly, any manufacturing-related reduction would be favorable to BEVs, though PHEVs would also benefit. One thing that this discussion has indeed impressed on me is the critical need to reduce the manufacturing carbon footprint. Will that fall with less CO2 intense electricity? Probably some, but I don't know if it will be enough. Might be worthy of further investigations, though.
 
One last thing Sly, you can only do your calculation for 93,000 miles. After that the car's battery doesn't have any CO2 impact per mile because it is completed from the assumed lifespan of 150,000 km.
CA requires batteries to be warrantied for 10 years and 150k miles. Manufacturers will build them to exceed this requirement to avoid warranty claims. 200k miles seems like a reasonable expectation for the lifetime of a battery, or any car in general. Interesting to think the average car will nearly cover the distance to the moon before heading to a junkyard.
 
One last thing Sly, you can only do your calculation for 93,000 miles. After that the car's battery doesn't have any CO2 impact per mile because it is completed from the assumed lifespan of 150,000 km.
That might be, I'll need to run the numbers to see. We'll need to wait and see just how many miles a battery is typically used before a car is junked. It could be so, but it is yet to be seen, even though there are some high-mileage EVs around, we don't know yet what the typical case will be.
 
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