Earlier quoted context omitted.
BMW claim that a diesel 3 series will get 61mpg. Volkswagen reckon a Golf 2.0 TDI will do 68mpg. Electric is still significantly better, but you didn't need pick a terrible diesel car as an example.
Volkswagen has already been caught cheating (on its emissions) —- not sure I would trust their claims without an independent third party checking on that.
CATL has announced a new “condensed” battery with 500 Wh/kg
301–310 of 919 posts
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#302I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…
The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…
Anything that doesn't require charging directly from the grid all the time, because although parts of the USA and Norway are ready for that, it's very tricky to get right globally.
Maybe hybrids like the Prius get to be so efficient that such cars will have a truly negligible impact on global warming.
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#303I just realized how much energy efficiency is being squeezed out of a Tesla. It's incredible. A normal diesel fueled sedan such as the Chevy Cruze diesel runs at about 31mpg, which is 13.2 km/l or 15.3 km/kg. Diesel has a mind-boggling 12700 Wh/kg energy density[1], which translates to an efficiency of ~827 Wh/km for the Chevy. By contrast, the Tesla Model S, has a ~540 kg battery[2]. At 272 Wh/kg (from the posted ar…
BMW claim that a diesel 3 series will get 61mpg. Volkswagen reckon a Golf 2.0 TDI will do 68mpg. Electric is still significantly better, but you didn't need pick a terrible diesel car as an example.
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#304Earlier quoted context omitted.
Various theoretical energy densities of batteries and gasoline: lead acid 123 Wh/kg lithium ion 250 Wh/kg zinc-oxygen 1,084 Wh/kg sodium-oxygen 1,605 Wh/kg lithium-sulfur 2,600 Wh/kg magnesium-oxygen 6,800 Wh/kg aluminium-oxygen 8,100 Wh/kg lithium-air 11,140 Wh/kg gasoline 12,700 Wh/kg from 2022, Asad A. Naqvi et. al., Aprotic lithium air batteries with oxygen-selective membranes , Table 1, https://link.springer.com…
And Uranium-235 about 1GWh/kg EDIT: this is for nuclear fuel enriched to 3% in a normal (not breeder) reactor 35000 MJ per 10g pellet https://whatisnuclear.com/energy-density.html Only a tiny fraction of the total energy is actually used
https://www.wolframalpha.com/input?i=100kwh%2F%282.5+gwh%2Fk...
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#305Earlier quoted context omitted.
I've got Civic e:hev, which has kind of similar setup. ICE does drive wheels in some situations (high speed, much power required), but mostly is just EV. It does not even have a gearbox, so there is only direct coupling from ICE to the wheels that can be engaged or disengaged (this is done automatically, you have no manual control over this). I really like this setup, because it gives economy, but also a range and I…
Isn't Honda the dark horse of hybrids? I remember riding in one and the owner explained that apparently Honda chose a hybrid architecture that was different that everyone else. The car's transition from electric to ICE was quite noticeable.
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#306Earlier quoted context omitted.
Less of the "S". With current flight patterns you need multiple gigawatts. Calculations based on 737s leaving Gatwick: Energy density of the fuel: 9.6kWh/L 900 flights per day = one flight every 96 seconds 26024.706L per flight Total energy per flight: 9.6 x 26024.706kWh = 250MWh give or take = 900GJ Total power supplied from Gatwick in the form of aviation fuel: 900GJ/96s = 9.375GW. That's not only outside the range…
That's assuming an overnight switch from what we have to all electric, for one of the busiest airports in the world. Thinking in terms of disruption (from the innovator sense), their top 3 destinations [0] are Dublin, Barcelona and Malaga. Skipping barcelona becauese it's as busy, I don't think it's out of reach to consider that a 737 could do a return trip to dublin or Malaga without charging. Another perspective is…
The way you'd have to do it is something like the Tesla approach: put small charging stations for luxury planes in as many airports as possible (because nobody, but nobody, will fly a plane into an airport they can't fly out of), and build out from there. That way you can do something financially interesting at SMR scale, and build momentum for the next step on something marketed as aspirational. Because the hardest SMR to build will be the first. Once you've got one, installing a second should be an easy sell. And two leads to four, and so on and so forth.
This is, of course, making the further assumption that something can be done about charging times. Getting 90GJ into a 737 currently takes about 23 minutes. That's 65MW, which is a nontrivial problem to solve all on its own; anything that slows down the recharge means longer queues to turn around, which, one way or another, means more land area or fewer flights for the airport, and worse economics for the operator.
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#307Someone should do a followup on all the batteries break-troughs on the front page of HN over the last 5 years and count how many got into production. Still, an announcement from a big company like this is a lot more credible than from research labs or small start-ups, IMO.
It’s interesting that battery stories generate so much opprobrium when battery performance has increased so dramatically over the last couple of decades.
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#308Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#309Earlier quoted context omitted.
I doubt this. The manufacturer are pushing subscription-base model. Used electric car won't become cheap
When I bought my used EV there were 2 options: Leaf or Zoe. As a high percentage of Zoe's had rented batteries, and the websites didn't have a filter for that, I didn't even bother test driving one.
Re: CATL has announced a new “condensed” battery with 500 Wh/kg
#310Earlier quoted context omitted.
The big reason for this is thermodynamics. A conventional internal combustion engine car has to convert chemical energy to kinetic energy - the absolute best theoretical efficiency of this might be 70%, but in practice it's more like 30%. Electric cars have to pay the same thermodynamic penalty, but they pay it at the power station (In practice, thanks to renewables, not all the electricity used to charge a car will…
> the absolute best theoretical efficiency of this might be 70% While ICE are heat engines with a theoretical limit of 70%, they’re more specialised subsets described by the Otto (gas) and Diesel (… diesel) cycles, which have a much lower theoretical maximum. Just plugging the temperature ranges into Carnot will give you a Carnot limit of 50%, and using Otto will yield 46% ( https://physics.stackexchange.com/a/98992…