I'm extremely sympathetic to the idea that hauling around an extra 500lb of batteries to every grocery store and school drop off when you'll only use them once a month is non-ideal, and that there's a lot of CO2 to be saved by putting those batteries to work on more daily commutes instead, but I wonder (and don't know of good data about) the real-world usage statistics, and whether such a trade is actually real.
For instance: my understanding is that, in practice, most PHEVs never get charged. People buy them because they get killer gas mileage, aren't much more expensive, and come with HOV lane stickers. Of course, I hear plenty of "I get 1000mi/tank average" anecdotes, but there's almost certainly hefty selection bias at play there, given, you know, I'm commenting on a substack called "ESG Hound." Anyway, if PHEVs amount to "better fuel economy" or "A jeep with HOV stickers" as I think the trend will lean, I wonder how much theoretical CO2 there actually is to recover.
And of course PHEVs present plenty of practical usage limitations favoring this behavior. Small batteries mean (much) slower charging in terms of real power, i.e. it takes you "approximately overnight" or "all day at work" in real-world terms to charge your Prius Prime for 25mi usable, where those same periods can also get you a full BEV charge. Of COURSE this isn't strictly true, but given the similarity of user experience, I think it's practically so. You could fully charge your Prime at L2 while you're in the grocery store, while the same in a tesla would require DC fast charging. But especially as PHEVs proliferate, I think a smaller and smaller percentage of drivers WILL. In other words, getting most of your miles from the wall in a PHEV is nearly impossible in an apartment, where it's "a little extra time spent DC fast charging" in a BEV.
Add to that that only half or less of a PHEV's power is electric - EV mode is an objectively stunted experience compared to hybrid mode. Again, I don't know how real-world usage shakes out, but I'd be willing to bet most PHEV owners (and even more future-owners) aren't so eco-motivated as to make that sacrifice consistently.
In other words, yes, PHEVs used optimally stand to remove a lot more CO2 per kWh of battery capacity vs BEVs, but BEVs come with a *guarantee* of grid-sourced miles, where PHEVs come with a substantial raft of incentives against electric miles. On top of which, PHEVs probably delay the collapse and price-increase of the gasoline market (to the extent that is even likely)
I think you've made a compelling case (as Toyota does) that PHEVs COULD be a better use of resources than full BEVs, but I think there's more to whether they are likely to be in practice.
this a a wonderful comment! Thanks so much. This is some nuance that is very important when looking at human behaviors. People don't act they way we think they will.
My intention was not to outright poo-poo EVs. In fact I think putting them in high ozone/smog pollution cities has a human health benefit that is more complex than CO2 accounting.
I just wanted to discuss the black and white thinking (oil bad! solar good! etc etc) and how it can be counterproductive. The logic you present here is great
Summed up, the case for PHEVs is based on 'discipline' / 'honesty' of the owner to really charge the PHEV. As a wise person said, life is about incentives. Consequently, the regulations must get the incentives right. That means, not giving tax breaks/rebates for a PHEV that never gets charged, but ... Taxing gasoline to the point that people have a very strong incentive to charge the PHEV ?
excellent observation! People often don't behave like rational actors.
My model obviously does not account for this. It was intended as a framework for thinking about how to allocated a supply limited material (batteries). But yes, if you were to make PHEV mandates, you'd want to make sure that the regulation doesn't overlook distortions in the market.
You are far too generous to the Tesla scenarios. The manufacturing emissions of big batteries are enormous (especially those made in China via coal power). It is unclear if a 100kWh car (especially an unreliable Tesla) will live long enough to have lower cradle-to-grave emissions than an efficient PHEV or HEV. Many Teslas need their batteries replaced more frequently that people realize, which is a huge emissions event. This (not behind paywall) has links to some of the studies. https://seekingalpha.com/article/4351863-electric-vehicle-subsidies-are-unsustainable
Oh undoubtedly a huge piece of the puzzle, but I wanted to bound the exercise with the presumption that these cells are being made regardless. I made nearly every assumption giving the BEV advocates the benefit of the doubt.
After re-reading that, my wording probably wasn't ideal. REM materials are geographically concentrated, so scaling operations requires significantly more incremental capital to increase yield. It's not at all comparable to, say, oil in this regard.
I'm working on something that I'll post eventually about the land use constraints on materials required for BEVs.
I'm extremely sympathetic to the idea that hauling around an extra 500lb of batteries to every grocery store and school drop off when you'll only use them once a month is non-ideal, and that there's a lot of CO2 to be saved by putting those batteries to work on more daily commutes instead, but I wonder (and don't know of good data about) the real-world usage statistics, and whether such a trade is actually real.
For instance: my understanding is that, in practice, most PHEVs never get charged. People buy them because they get killer gas mileage, aren't much more expensive, and come with HOV lane stickers. Of course, I hear plenty of "I get 1000mi/tank average" anecdotes, but there's almost certainly hefty selection bias at play there, given, you know, I'm commenting on a substack called "ESG Hound." Anyway, if PHEVs amount to "better fuel economy" or "A jeep with HOV stickers" as I think the trend will lean, I wonder how much theoretical CO2 there actually is to recover.
And of course PHEVs present plenty of practical usage limitations favoring this behavior. Small batteries mean (much) slower charging in terms of real power, i.e. it takes you "approximately overnight" or "all day at work" in real-world terms to charge your Prius Prime for 25mi usable, where those same periods can also get you a full BEV charge. Of COURSE this isn't strictly true, but given the similarity of user experience, I think it's practically so. You could fully charge your Prime at L2 while you're in the grocery store, while the same in a tesla would require DC fast charging. But especially as PHEVs proliferate, I think a smaller and smaller percentage of drivers WILL. In other words, getting most of your miles from the wall in a PHEV is nearly impossible in an apartment, where it's "a little extra time spent DC fast charging" in a BEV.
Add to that that only half or less of a PHEV's power is electric - EV mode is an objectively stunted experience compared to hybrid mode. Again, I don't know how real-world usage shakes out, but I'd be willing to bet most PHEV owners (and even more future-owners) aren't so eco-motivated as to make that sacrifice consistently.
In other words, yes, PHEVs used optimally stand to remove a lot more CO2 per kWh of battery capacity vs BEVs, but BEVs come with a *guarantee* of grid-sourced miles, where PHEVs come with a substantial raft of incentives against electric miles. On top of which, PHEVs probably delay the collapse and price-increase of the gasoline market (to the extent that is even likely)
I think you've made a compelling case (as Toyota does) that PHEVs COULD be a better use of resources than full BEVs, but I think there's more to whether they are likely to be in practice.
this a a wonderful comment! Thanks so much. This is some nuance that is very important when looking at human behaviors. People don't act they way we think they will.
My intention was not to outright poo-poo EVs. In fact I think putting them in high ozone/smog pollution cities has a human health benefit that is more complex than CO2 accounting.
I just wanted to discuss the black and white thinking (oil bad! solar good! etc etc) and how it can be counterproductive. The logic you present here is great
Thanks for the comment
Summed up, the case for PHEVs is based on 'discipline' / 'honesty' of the owner to really charge the PHEV. As a wise person said, life is about incentives. Consequently, the regulations must get the incentives right. That means, not giving tax breaks/rebates for a PHEV that never gets charged, but ... Taxing gasoline to the point that people have a very strong incentive to charge the PHEV ?
excellent observation! People often don't behave like rational actors.
My model obviously does not account for this. It was intended as a framework for thinking about how to allocated a supply limited material (batteries). But yes, if you were to make PHEV mandates, you'd want to make sure that the regulation doesn't overlook distortions in the market.
Thanks for reading
You are far too generous to the Tesla scenarios. The manufacturing emissions of big batteries are enormous (especially those made in China via coal power). It is unclear if a 100kWh car (especially an unreliable Tesla) will live long enough to have lower cradle-to-grave emissions than an efficient PHEV or HEV. Many Teslas need their batteries replaced more frequently that people realize, which is a huge emissions event. This (not behind paywall) has links to some of the studies. https://seekingalpha.com/article/4351863-electric-vehicle-subsidies-are-unsustainable
Oh undoubtedly a huge piece of the puzzle, but I wanted to bound the exercise with the presumption that these cells are being made regardless. I made nearly every assumption giving the BEV advocates the benefit of the doubt.
Thanks for the link
“geographic footprint is small” for rare earth mineral extraction?
After re-reading that, my wording probably wasn't ideal. REM materials are geographically concentrated, so scaling operations requires significantly more incremental capital to increase yield. It's not at all comparable to, say, oil in this regard.
I'm working on something that I'll post eventually about the land use constraints on materials required for BEVs.
Thanks for the comment