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Anyone care to explain what they mean by: > As any EV advocate knows, vehicles powered by batteries and electricity are far more efficient than conventional ca

Anyone care to explain what they mean by: > As any EV advocate knows, vehicles powered by batteries and electricity are far more efficient than conventional cars powered by last century internal combustion technology. Because they are comparing energy storage with energy creation. And as far as I know fuel holds more energy per cubic centimeter than batteries.

mdeeks 3y ago
I think they are referring to energy efficiency. If I remember correctly gas cars lose about 80% of their energy propelling you forward but EVs only lose about 10-20%. My numbers might not be exact but that’s the general range.
- jtriangle 3y ago
  Best case EV charging is about 80% efficient from the grid, power transmission losses are 7-14% depending on your local grid, EV power usage, from the batteries, is also somewhere around 80% Efficient Gasoline engines come in at 25-30% efficient, Diesel somewhere around 35%. Hybrids can boost that some, because they can scavenge energy that'd otherwise be lost, but only somewhere between 5 and 15% in real world scenarios.
  - mdeeks 3y ago
    Article I just read says they score EVs higher because of regenerative breaking. 87-91% go to the wheels. In any case, very efficient. https://www.motortrend.com/uploads/2022/08/Screen-Shot-2022-08-12-at-3.46.59-PM.png?w=393 https://www.motortrend.com/uploads/2022/08/Screen-Shot-2022-...
  - jbm 3y ago
    On a tangent, I've been spending the past month looking to see any form of charging I can do from a solar panel to the car without conversion losses and coming up blank. The battery is DC, the panel is DC; but you can't do direct DC charging at home, so you end up with DC -> AC -> DC. It would be nice to get that last 20% efficiency back but I haven't found it.
    - jtriangle 3y ago
      You'd have to be able to convince the car that you're able to provide DC charging. Far from an impossibility, but a very roll your own kindof system, and you'll likely need some beefy DC/DC converters to do so. You could also, similarly, subvert the car entirely and just disconnect it from the car, charge it from the panels/DC converter, and reconnect it when finished.
    - ChrisMarshallNY 3y ago
      I'm pretty sure that superchargers are DC.
      - jbm 3y ago
        Unfortunately they don't sell supercharger components at home (and I won't be installing a battery to get that 150kw capacity at home). On a side note, I don't want to necessarily fast charge the car; I just want to use the electricity from my solar panel in the most efficient possible way; that would be heating water, powering stuff in the house and charging my car; the last of which probably would take the most electricity.
  - cyberax 3y ago
    > Best case EV charging is about 80% efficient from the grid, power transmission losses are 7-14% depending on your local grid, EV power usage, from the batteries, is also somewhere around 80% Pure BS. Tesla is at 95% from outlet to battery on 240V, and it can be even more (depending on the need to run cooling/heating). Grid transmission losses average at around 5% nationally, but it heavily depends on the location.
Tagbert 3y ago
That statement compares the one set of vehicles to another. It is using “batteries and electricity” to identify one set and “internal combustion” to identify another but it seems to be talking about the whole vehicle. In that context, EVs are massively more efficient in terms of energy used to travel than ICEVs are. Energy storage capacity and density are a different question.
jtriangle 3y ago
If you charge a tesla off a combined cycle oil fired power plant, both good examples of efficiency, after transmission/charging losses, you end up somewhere in the neighborhood of 28-30mpg of bunker oil. I haven't bothered working out what the equivalent diesel or gasoline consumption is, just that both have a little higher energy density, and 30mpg is a good enough ballpark number to compare things by. More or less, if you're concerned with CO2 output, a hybrid car is a better solution until we can build enough carbon free base load (currently nuclear, eventually fusion).
- megaman821 3y ago
  You are going to have to show you math here, because that is the lowest number I have ever seen. Not to mention, you just made up a power generation mix that doesn't exist, what nation uses mostly combined-cycle bunker oil plants? Will your next calculation feature power plant that runs off of old tires?
  - anticensor 3y ago
    Cyprus does.
  - jtriangle 3y ago
    As I said, it's just a point of comparison that I could get good numbers on. Power plant operators are very tight lipped about fuel/kwh generated, but, people selling very large, industrial gensets happily offer those numbers, and they're seemingly honest about it from what I could tell. Generally, combined cycle plants are ~50% efficient in terms of fuel to power, energy density of bunker C is 40Mj/kg, transmission losses are variable, but figure them at 10% so it's ballpark and easy, EV chargers are about 80% efficient, car extracts 80% of the energy it draws from the battery in normal use (remember the motor isn't all that's being powered). So there's alot of loss along the way. Some of that is solvable, some of that is improvable, but ultimately the solution is clean, cheap power so the losses don't matter. Until we've got that, hybrid drivetrains are a good solution, provided they're implemented well. I know you're being an asshole with the whole tires comment, but, it would be a fun bit of math to do.

mdeeks 3y ago

I think they are referring to energy efficiency. If I remember correctly gas cars lose about 80% of their energy propelling you forward but EVs only lose about 10-20%. My numbers might not be exact but that’s the general range.

jtriangle 3y ago
Best case EV charging is about 80% efficient from the grid, power transmission losses are 7-14% depending on your local grid, EV power usage, from the batteries, is also somewhere around 80% Efficient Gasoline engines come in at 25-30% efficient, Diesel somewhere around 35%. Hybrids can boost that some, because they can scavenge energy that'd otherwise be lost, but only somewhere between 5 and 15% in real world scenarios.
- mdeeks 3y ago
  Article I just read says they score EVs higher because of regenerative breaking. 87-91% go to the wheels. In any case, very efficient. https://www.motortrend.com/uploads/2022/08/Screen-Shot-2022-08-12-at-3.46.59-PM.png?w=393 https://www.motortrend.com/uploads/2022/08/Screen-Shot-2022-...
- jbm 3y ago
  On a tangent, I've been spending the past month looking to see any form of charging I can do from a solar panel to the car without conversion losses and coming up blank. The battery is DC, the panel is DC; but you can't do direct DC charging at home, so you end up with DC -> AC -> DC. It would be nice to get that last 20% efficiency back but I haven't found it.
  - jtriangle 3y ago
    You'd have to be able to convince the car that you're able to provide DC charging. Far from an impossibility, but a very roll your own kindof system, and you'll likely need some beefy DC/DC converters to do so. You could also, similarly, subvert the car entirely and just disconnect it from the car, charge it from the panels/DC converter, and reconnect it when finished.
  - ChrisMarshallNY 3y ago
    I'm pretty sure that superchargers are DC.
    - jbm 3y ago
      Unfortunately they don't sell supercharger components at home (and I won't be installing a battery to get that 150kw capacity at home). On a side note, I don't want to necessarily fast charge the car; I just want to use the electricity from my solar panel in the most efficient possible way; that would be heating water, powering stuff in the house and charging my car; the last of which probably would take the most electricity.
- cyberax 3y ago
  > Best case EV charging is about 80% efficient from the grid, power transmission losses are 7-14% depending on your local grid, EV power usage, from the batteries, is also somewhere around 80% Pure BS. Tesla is at 95% from outlet to battery on 240V, and it can be even more (depending on the need to run cooling/heating). Grid transmission losses average at around 5% nationally, but it heavily depends on the location.

Tagbert 3y ago

That statement compares the one set of vehicles to another. It is using “batteries and electricity” to identify one set and “internal combustion” to identify another but it seems to be talking about the whole vehicle. In that context, EVs are massively more efficient in terms of energy used to travel than ICEVs are. Energy storage capacity and density are a different question.

jtriangle 3y ago

If you charge a tesla off a combined cycle oil fired power plant, both good examples of efficiency, after transmission/charging losses, you end up somewhere in the neighborhood of 28-30mpg of bunker oil. I haven't bothered working out what the equivalent diesel or gasoline consumption is, just that both have a little higher energy density, and 30mpg is a good enough ballpark number to compare things by. More or less, if you're concerned with CO2 output, a hybrid car is a better solution until we can build enough carbon free base load (currently nuclear, eventually fusion).

megaman821 3y ago
You are going to have to show you math here, because that is the lowest number I have ever seen. Not to mention, you just made up a power generation mix that doesn't exist, what nation uses mostly combined-cycle bunker oil plants? Will your next calculation feature power plant that runs off of old tires?
- anticensor 3y ago
  Cyprus does.
- jtriangle 3y ago
  As I said, it's just a point of comparison that I could get good numbers on. Power plant operators are very tight lipped about fuel/kwh generated, but, people selling very large, industrial gensets happily offer those numbers, and they're seemingly honest about it from what I could tell. Generally, combined cycle plants are ~50% efficient in terms of fuel to power, energy density of bunker C is 40Mj/kg, transmission losses are variable, but figure them at 10% so it's ballpark and easy, EV chargers are about 80% efficient, car extracts 80% of the energy it draws from the battery in normal use (remember the motor isn't all that's being powered). So there's alot of loss along the way. Some of that is solvable, some of that is improvable, but ultimately the solution is clean, cheap power so the losses don't matter. Until we've got that, hybrid drivetrains are a good solution, provided they're implemented well. I know you're being an asshole with the whole tires comment, but, it would be a fun bit of math to do.