5 ms·

Intuitively 270g per kWh seemed high to me, but to put it in perspective a Tesla model 3 does about 100km per 11.9~14.9kWh (according to Google). So taking the

by jeeeb 5y ago

Intuitively 270g per kWh seemed high to me, but to put it in perspective a Tesla model 3 does about 100km per 11.9~14.9kWh (according to Google). So taking the larger estimate (and ignoring transmission etc losses) at 270g/KWh that gives emissions of around 41g/km. Comparatively though my 2021 Camry hybrid has emissions of 96g/km. So, assuming the plants are primarily being used to level out variable renewable production, I guess that is a reasonable standard for bridging a technology gap.

Rebelgecko 5y ago
I do wonder, how significant are inefficiencies in transmission, charging, and storage? With cheap lithium batteries I've bought (like phone power banks), I usually need to subtract about 25% from the rated capacity to figure out how many times it'll fill my phone's battery. Although hopefully cars are more efficient
- jeeeb 5y ago
  Your right! I was just looking at it from the point of view of how efficient does this standard require power plants to be, since 270g of CO2 to run a 1kw heater for an hour seemed high. If you look at the whole energy supply chain though the picture is probably a lot worse for both, in particular when you account for things like methane leaks or the emissions from transporting + refining oil.
  - deleted 5y ago
    [deleted]
- arcticbull 5y ago
  Losses on the big high-voltage wires average about 2% in the US. Losses on lower-voltage distribution wires average 4% on top of that - so about 6% in total. [1] Lithium Ion batteries charge near 100% efficiency. [2] In terms of storage (specifically self-discharge), Lithium Ion batteries lose 5% in 24 hours, then 1-2% per month thereafter - but can be as low as 0.35% per month. [3, 4] [1] http://insideenergy.org/2015/11/06/lost-in-transmission-how-much-electricity-disappears-between-a-power-plant-and-your-plug/ http://insideenergy.org/2015/11/06/lost-in-transmission-how-... [2] https://www.powertechsystems.eu/home/tech-corner/lithium-ion-battery-advantages/ https://www.powertechsystems.eu/home/tech-corner/lithium-ion... [3] https://batteryuniversity.com/article/bu-802b-what-does-elevated-self-discharge-do%C2%A0 https://batteryuniversity.com/article/bu-802b-what-does-elev... [4] https://en.wikipedia.org/wiki/Lithium-ion_battery https://en.wikipedia.org/wiki/Lithium-ion_battery
  - _fizz_buzz_ 5y ago
    > Lithium Ion batteries charge near 100% efficiency The power electronics to charge the battery also have losses. Although they are getting really good, my guess would be something better than 95% efficiency in the battery charger. There are some really great improvements in power transistors recently though, so this number will still have some room for improvement.
    - arcticbull 5y ago
      Thank you for calling that out. I was going to say something about that, and budget say 10% to switching regulators. With car-scale charging systems I just didn't have enough data to ballpark efficiency.
matsemann 5y ago
All very high numbers. The key to solving climate change isn't to do as before, just slightly more efficient. Electric cars won't solve anything, especially not if they are indirectly powered by fossil fuels. Make cities walkable, bikeable and public transportable. That will have far bigger impact than people buying new electric cars.
- consp 5y ago
  This is far more a us/Canada problem than a European one, and this is a European proposal.
  - matsemann 5y ago
    Don't agree. While car culture is far worse in America, we're still far too dependent on cars here in Europe as well in situations where it isn't necessary. Almost all planning revolves around cars, and then some pedestrian stuff is tacked haphazardly on at the end.
    - HatchedLake721 5y ago
      What is “we here in Europe”? It’s equivalent to saying “we on planet earth do it this way”. It’s 30+ completely different countries with different infrastructure, different views on how things should be done and different decision makers. Your experience in X is different to Y. E.g. as far as I know, no one in Netherlands “haphazardly tacks some pedestrian stuff at the end”. Of course you’ll be more dependent on a car if you live in some parts and of course some will have cars where it isn’t necessary. What we all do know and believe we can agree on, is that public transport (mainly trains and buses) in all of Europe is miles ahead and puts United States to shame. There’s a reason why we don’t really have drive through ATMs and cities with towns are walkable and pedestrian first, while cars are second or even third behind bikes.
  - wott 5y ago
    Please update your views of European urbanism (browsing Google's aerial photos should be enough). Urban sprawl is the defining key of the last 50 years. Here is a starting point, miles and miles away from the historical centre of Toulouse: https://www.google.fr/maps/@43.537841,1.2268468,2639m/data=!3m1!1e3?hl=fr https://www.google.fr/maps/@43.537841,1.2268468,2639m/data=!... Now it is not only happening around cities, around big towns, around small towns, it also happens at unprecedented speed around the tiniest villages. A site that puts side by side aerials from now and from before urban sprawl: https://remonterletemps.ign.fr/comparer/basic?x=1.212446&y=42.884138&z=17&layer1=ORTHOIMAGERY.ORTHOPHOTOS&layer2=ORTHOIMAGERY.ORTHOPHOTOS.1950-1965&mode=doubleMap https://remonterletemps.ign.fr/comparer/basic?x=1.212446&y=4... Back in huge cities. The city of Paris is much less populated than one century ago. Now it represents only 1/6th of the population of its urban area, an ogre which has swallowed almost 2000 municipalities (two thousand!). Elsewhere in the country, you see urban areas from cities multiple dozens of miles apart joining in a continuous sprawl. Heck, even in my deep and remote area disconnected from any city or even town, there is now 5 miles of sprawl joining the 3 villages of the valley in continuous strips along the roads; before the sprawl, population of my municipality was 50% higher, and yet 80-90% of the now occupied space was free.

by jeeeb 5y ago

Rebelgecko 5y ago

I do wonder, how significant are inefficiencies in transmission, charging, and storage? With cheap lithium batteries I've bought (like phone power banks), I usually need to subtract about 25% from the rated capacity to figure out how many times it'll fill my phone's battery. Although hopefully cars are more efficient

jeeeb 5y ago
Your right! I was just looking at it from the point of view of how efficient does this standard require power plants to be, since 270g of CO2 to run a 1kw heater for an hour seemed high. If you look at the whole energy supply chain though the picture is probably a lot worse for both, in particular when you account for things like methane leaks or the emissions from transporting + refining oil.
- deleted 5y ago
  [deleted]
arcticbull 5y ago
Losses on the big high-voltage wires average about 2% in the US. Losses on lower-voltage distribution wires average 4% on top of that - so about 6% in total. [1] Lithium Ion batteries charge near 100% efficiency. [2] In terms of storage (specifically self-discharge), Lithium Ion batteries lose 5% in 24 hours, then 1-2% per month thereafter - but can be as low as 0.35% per month. [3, 4] [1] http://insideenergy.org/2015/11/06/lost-in-transmission-how-much-electricity-disappears-between-a-power-plant-and-your-plug/ http://insideenergy.org/2015/11/06/lost-in-transmission-how-... [2] https://www.powertechsystems.eu/home/tech-corner/lithium-ion-battery-advantages/ https://www.powertechsystems.eu/home/tech-corner/lithium-ion... [3] https://batteryuniversity.com/article/bu-802b-what-does-elevated-self-discharge-do%C2%A0 https://batteryuniversity.com/article/bu-802b-what-does-elev... [4] https://en.wikipedia.org/wiki/Lithium-ion_battery https://en.wikipedia.org/wiki/Lithium-ion_battery
- _fizz_buzz_ 5y ago
  > Lithium Ion batteries charge near 100% efficiency The power electronics to charge the battery also have losses. Although they are getting really good, my guess would be something better than 95% efficiency in the battery charger. There are some really great improvements in power transistors recently though, so this number will still have some room for improvement.
  - arcticbull 5y ago
    Thank you for calling that out. I was going to say something about that, and budget say 10% to switching regulators. With car-scale charging systems I just didn't have enough data to ballpark efficiency.

matsemann 5y ago

All very high numbers. The key to solving climate change isn't to do as before, just slightly more efficient. Electric cars won't solve anything, especially not if they are indirectly powered by fossil fuels. Make cities walkable, bikeable and public transportable. That will have far bigger impact than people buying new electric cars.

consp 5y ago
This is far more a us/Canada problem than a European one, and this is a European proposal.
- matsemann 5y ago
  Don't agree. While car culture is far worse in America, we're still far too dependent on cars here in Europe as well in situations where it isn't necessary. Almost all planning revolves around cars, and then some pedestrian stuff is tacked haphazardly on at the end.
  - HatchedLake721 5y ago
    What is “we here in Europe”? It’s equivalent to saying “we on planet earth do it this way”. It’s 30+ completely different countries with different infrastructure, different views on how things should be done and different decision makers. Your experience in X is different to Y. E.g. as far as I know, no one in Netherlands “haphazardly tacks some pedestrian stuff at the end”. Of course you’ll be more dependent on a car if you live in some parts and of course some will have cars where it isn’t necessary. What we all do know and believe we can agree on, is that public transport (mainly trains and buses) in all of Europe is miles ahead and puts United States to shame. There’s a reason why we don’t really have drive through ATMs and cities with towns are walkable and pedestrian first, while cars are second or even third behind bikes.
- wott 5y ago
  Please update your views of European urbanism (browsing Google's aerial photos should be enough). Urban sprawl is the defining key of the last 50 years. Here is a starting point, miles and miles away from the historical centre of Toulouse: https://www.google.fr/maps/@43.537841,1.2268468,2639m/data=!3m1!1e3?hl=fr https://www.google.fr/maps/@43.537841,1.2268468,2639m/data=!... Now it is not only happening around cities, around big towns, around small towns, it also happens at unprecedented speed around the tiniest villages. A site that puts side by side aerials from now and from before urban sprawl: https://remonterletemps.ign.fr/comparer/basic?x=1.212446&y=42.884138&z=17&layer1=ORTHOIMAGERY.ORTHOPHOTOS&layer2=ORTHOIMAGERY.ORTHOPHOTOS.1950-1965&mode=doubleMap https://remonterletemps.ign.fr/comparer/basic?x=1.212446&y=4... Back in huge cities. The city of Paris is much less populated than one century ago. Now it represents only 1/6th of the population of its urban area, an ogre which has swallowed almost 2000 municipalities (two thousand!). Elsewhere in the country, you see urban areas from cities multiple dozens of miles apart joining in a continuous sprawl. Heck, even in my deep and remote area disconnected from any city or even town, there is now 5 miles of sprawl joining the 3 villages of the valley in continuous strips along the roads; before the sprawl, population of my municipality was 50% higher, and yet 80-90% of the now occupied space was free.