4 ms·

>you are not considering the difference in efficiency between a power plant and a car with an internal combustion engine. The well-to-wheels analysis for an EV

>you are not considering the difference in efficiency between a power plant and a car with an internal combustion engine. The well-to-wheels analysis for an EV powered by a largely fossil-fuelled power grid is not good. Transmission and battery losses wipe out most of the (quite small) gains. >a state like Utah in the US an ev becomes greener after the equivalent of few tens of gas tanks Would love to see the source for that. Last time I checked, with a relatively "green" grid (something that almost everywhere in the US is a long way from achieving), the CO2 crossover point for an EV is at 20,000+ miles.

Schroedingersat 4y ago
The sleight of hand is in the definition of 'equivalent'. Batteries are expensive and motors are dirt cheap, so the only EVs with decent range are super high end, performance, luxury models. Compared to a 500hp luxury SUV they're great. Compared to an econobox they use about the same amount of energy per km. They're up if you compare whole system emissions for the car vs. Emissions at a ff plant. If you add in the fugitive methane or horror show that is coal mining and ash they're on par again.
- jryhjythtr 4y ago
  >They're up if you compare whole system emissions for the car vs. Emissions at a ff plant. The sleight of hand is in the definition of "emissions". If you mean CO2 - then no, not really. If you are powering your EV with a fossil-fuel powered grid, then the transmission and battery losses make up for the small gain in power plant efficiency over an ICE (as I already said). The CO2 argument for an EV only works when the grid has a substantial "green generation" component. If you mean "emissions that are immediately bad for people" - it depends who you are talking about. EVs replace tailpipe emissions at the point of use with centralised emissions, both at the point of manufacture, and at the point of charging power generation (which will most likely be in a Western country with well-controlled emissions). As a cyclist, I have to admit it's nice not to breathe in tailpipe fumes. I try not to worry too much about all the damage being done by EV manufacture far far away from me.
  - Schroedingersat 4y ago
    > If you mean CO2 - then no, not really. If you are powering your EV with a fossil-fuel powered grid, then the transmission and battery losses make up for the small gain in power plant efficiency over an ICE (as I already said). The CO2 argument for an EV only works when the grid has a substantial "green generation" component. EVs waste a lot less power than ICEs after the motor. Much of it not for any reason that couldn't be true of an ICE as well except for design priorities. 200Wh/km of wall socket power is about 60MJ per 100km. If that came from coal in a modern-ish plant it's about 10-15kg of CO2. From gas it's around 5-8kg. A highly efficient ICE produces 50gCO2e per km or 5kg for the same distance. This looks good until you consider that's not where the supply chain ends. Producing that petrol took another 3kg, or maybe 5kg if it was tar sands. A mostly-ff mix EV starts to look good here. But it's also not end of the line for the gas plant. Fugitive methane will double its GHG output. Coal has NOx and some deleterious effects that aren't precisely GHG but are just as bad. So the tesla produces more than the econobox. But an 'equivalent' once you game the metrics and compare against a Porsche Cayanne produces more than the tesla. Really to reduce emissions quickly in urban or suburban areas we need more vehicles that look like a Zev, an Aptera, suzuki samba, a golf cart or a bicycle etc. and fewer that resemble a tesla or a monster truck (as well as more rail based vehicles).
    - jryhjythtr 4y ago
      >EVs waste a lot less power than ICEs after the motor. I'm talking about electrical transmission losses. The worst-case is for high-current, domestic loads, where about 15% of the power from the electrical power generator is lost. Add in another approx. 15% for charging and discharging the EV battery, and it's not so good. >200Wh/km of wall socket power is about 60MJ per 100km You forgot the above losses. >A mostly-ff mix EV starts to look good here. Not at all. By your (very optimistic) calculations, they are about the same. You'll never pay off the CO2 debt of manufacturing the EV battery, let alone start averting the climate catastrophe! >Really to reduce emissions quickly in urban or suburban areas we need more vehicles that look like a Zev, an Aptera, suzuki samba, a golf cart or a bicycle etc. and fewer that resemble a tesla or a monster truck (as well as more rail based vehicles). Very true. Weird that all of the currently-pushed solutions involve large and expensive EVs that barely do any good.

Schroedingersat 4y ago

The sleight of hand is in the definition of 'equivalent'. Batteries are expensive and motors are dirt cheap, so the only EVs with decent range are super high end, performance, luxury models. Compared to a 500hp luxury SUV they're great. Compared to an econobox they use about the same amount of energy per km. They're up if you compare whole system emissions for the car vs. Emissions at a ff plant. If you add in the fugitive methane or horror show that is coal mining and ash they're on par again.

jryhjythtr 4y ago
>They're up if you compare whole system emissions for the car vs. Emissions at a ff plant. The sleight of hand is in the definition of "emissions". If you mean CO2 - then no, not really. If you are powering your EV with a fossil-fuel powered grid, then the transmission and battery losses make up for the small gain in power plant efficiency over an ICE (as I already said). The CO2 argument for an EV only works when the grid has a substantial "green generation" component. If you mean "emissions that are immediately bad for people" - it depends who you are talking about. EVs replace tailpipe emissions at the point of use with centralised emissions, both at the point of manufacture, and at the point of charging power generation (which will most likely be in a Western country with well-controlled emissions). As a cyclist, I have to admit it's nice not to breathe in tailpipe fumes. I try not to worry too much about all the damage being done by EV manufacture far far away from me.
- Schroedingersat 4y ago
  > If you mean CO2 - then no, not really. If you are powering your EV with a fossil-fuel powered grid, then the transmission and battery losses make up for the small gain in power plant efficiency over an ICE (as I already said). The CO2 argument for an EV only works when the grid has a substantial "green generation" component. EVs waste a lot less power than ICEs after the motor. Much of it not for any reason that couldn't be true of an ICE as well except for design priorities. 200Wh/km of wall socket power is about 60MJ per 100km. If that came from coal in a modern-ish plant it's about 10-15kg of CO2. From gas it's around 5-8kg. A highly efficient ICE produces 50gCO2e per km or 5kg for the same distance. This looks good until you consider that's not where the supply chain ends. Producing that petrol took another 3kg, or maybe 5kg if it was tar sands. A mostly-ff mix EV starts to look good here. But it's also not end of the line for the gas plant. Fugitive methane will double its GHG output. Coal has NOx and some deleterious effects that aren't precisely GHG but are just as bad. So the tesla produces more than the econobox. But an 'equivalent' once you game the metrics and compare against a Porsche Cayanne produces more than the tesla. Really to reduce emissions quickly in urban or suburban areas we need more vehicles that look like a Zev, an Aptera, suzuki samba, a golf cart or a bicycle etc. and fewer that resemble a tesla or a monster truck (as well as more rail based vehicles).
  - jryhjythtr 4y ago
    >EVs waste a lot less power than ICEs after the motor. I'm talking about electrical transmission losses. The worst-case is for high-current, domestic loads, where about 15% of the power from the electrical power generator is lost. Add in another approx. 15% for charging and discharging the EV battery, and it's not so good. >200Wh/km of wall socket power is about 60MJ per 100km You forgot the above losses. >A mostly-ff mix EV starts to look good here. Not at all. By your (very optimistic) calculations, they are about the same. You'll never pay off the CO2 debt of manufacturing the EV battery, let alone start averting the climate catastrophe! >Really to reduce emissions quickly in urban or suburban areas we need more vehicles that look like a Zev, an Aptera, suzuki samba, a golf cart or a bicycle etc. and fewer that resemble a tesla or a monster truck (as well as more rail based vehicles). Very true. Weird that all of the currently-pushed solutions involve large and expensive EVs that barely do any good.