4 ms·

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

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.
  - entropicgravity 3y ago
    To my knowledge EV chargers are close to 90% efficient from wall to tire. So about 5% loss going to the battery and 5% loss going from battery to drive the tires. This should get a little bit better as higher voltage harnesses appear in EV's.
- dgacmu 3y ago
  Bermuda. And a few other island states/nations. But they're the edge cases and most are seeing continued growth of solar, so hopefully not for long... (The case of Bermuda is fascinating and annoying to me. You would think that they were really well positioned to take advantage of solar, but the banks there are very conservative about financing things like residential, solar and so it's been very slow to take off, despite energy prices that are some of the highest in the world)
conjecTech 3y ago
Hawaii is the only state that produces a significant fraction of its electricity from oil. Something like 40% of continental US electricity is already low-carbon(nuclear, wind, solar) and the bulk of the rest is natural gas, which produces significantly less emissions per unit of energy than diesel. From a CO2 perspective, it is almost certainly better to drive a full electric vehicle, and that will only become more true as we continue to transition production.
Forbo 3y ago
Everything I've read has stated that even if you ran your EV off of a grid powered entirely by coal you still come out with less carbon output than ICE (after about 6 years of use). Do you have citations? Edit for a quick citation for my claim: https://graphics.reuters.com/ELECTRIC-VEHICLES/EMISSIONS/rlgpdrmjmpo/chart.png https://graphics.reuters.com/ELECTRIC-VEHICLES/EMISSIONS/rlg...
thebruce87m 3y ago
What does your grid look like? Here’s mine: https://electricityproduction.uk/in/scotland/ https://electricityproduction.uk/in/scotland/

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.
- entropicgravity 3y ago
  To my knowledge EV chargers are close to 90% efficient from wall to tire. So about 5% loss going to the battery and 5% loss going from battery to drive the tires. This should get a little bit better as higher voltage harnesses appear in EV's.
dgacmu 3y ago
Bermuda. And a few other island states/nations. But they're the edge cases and most are seeing continued growth of solar, so hopefully not for long... (The case of Bermuda is fascinating and annoying to me. You would think that they were really well positioned to take advantage of solar, but the banks there are very conservative about financing things like residential, solar and so it's been very slow to take off, despite energy prices that are some of the highest in the world)

conjecTech 3y ago

Hawaii is the only state that produces a significant fraction of its electricity from oil. Something like 40% of continental US electricity is already low-carbon(nuclear, wind, solar) and the bulk of the rest is natural gas, which produces significantly less emissions per unit of energy than diesel. From a CO2 perspective, it is almost certainly better to drive a full electric vehicle, and that will only become more true as we continue to transition production.

Forbo 3y ago

Everything I've read has stated that even if you ran your EV off of a grid powered entirely by coal you still come out with less carbon output than ICE (after about 6 years of use). Do you have citations? Edit for a quick citation for my claim: https://graphics.reuters.com/ELECTRIC-VEHICLES/EMISSIONS/rlgpdrmjmpo/chart.png https://graphics.reuters.com/ELECTRIC-VEHICLES/EMISSIONS/rlg...

thebruce87m 3y ago

What does your grid look like? Here’s mine: https://electricityproduction.uk/in/scotland/ https://electricityproduction.uk/in/scotland/