3 ms·

Power plants operate at a much higher efficiency than internal combustion engines, on cheaper and more diversified fuel sources, including renewable. [Electric

Power plants operate at a much higher efficiency than internal combustion engines, on cheaper and more diversified fuel sources, including renewable. [Electric motors and batteries also have relatively little energy waste, making the system as a whole more efficient to operate, especially when you consider being able to leverage the superior distribution infrastructure of the electric grid versus the relatively sparse network of fuel stations. Consider that most fuel stations receive their supply by tanker-truck, which introduces yet more inefficiency.]

TylerE 14y ago
On the other hand, they also require charging infrastructure, and there is some loss in transmission, so you don't get to keep all of that efficiency.
excuse-me 14y ago
Not quite so clear cut for a small car. A small common rail diesel engine in a car gets close to 40%, a coal power plant runs at about 45%. Add in transmission losses and charging/battery/electric motor and the diesel g CO2/km is probably better.
- WiseWeasel 14y ago
  Coal is significantly cheaper than diesel, and coal power plants have filtration systems to reduce their emissions; diesel engines not so much.
  - TylerE 14y ago
    You should really check out modern diesels. A VW TDI engine has cleaner exhaust than a typical modern gasser. You could hold up a white handkerchief to the tailpipe and it'd stay clean.
  - excuse-me 14y ago
    Coal stations have flue gas sulfur filters, but still emit a lot of CO2 (and a lot of radioactivity), road diesel is ultra low sulfur in civilized countries.
- fennecfoxen 14y ago
  The US is presently doing a lot to switch over to natural gas, which has a lot less carbon-per-kWh than coal. If that's what they have in your area, the figures look better. Also good for the figures: if you happened to be doing your charging off-peak such that you're not actually adding to the emissions that would otherwise be emitted by idling power plants. (Or if you live in an area with good hydro/nuclear and the like.) Of course, that's not really transparent to the electricity user in most cases.

TylerE 14y ago

On the other hand, they also require charging infrastructure, and there is some loss in transmission, so you don't get to keep all of that efficiency.

excuse-me 14y ago

Not quite so clear cut for a small car. A small common rail diesel engine in a car gets close to 40%, a coal power plant runs at about 45%. Add in transmission losses and charging/battery/electric motor and the diesel g CO2/km is probably better.

WiseWeasel 14y ago
Coal is significantly cheaper than diesel, and coal power plants have filtration systems to reduce their emissions; diesel engines not so much.
- TylerE 14y ago
  You should really check out modern diesels. A VW TDI engine has cleaner exhaust than a typical modern gasser. You could hold up a white handkerchief to the tailpipe and it'd stay clean.
- excuse-me 14y ago
  Coal stations have flue gas sulfur filters, but still emit a lot of CO2 (and a lot of radioactivity), road diesel is ultra low sulfur in civilized countries.
fennecfoxen 14y ago
The US is presently doing a lot to switch over to natural gas, which has a lot less carbon-per-kWh than coal. If that's what they have in your area, the figures look better. Also good for the figures: if you happened to be doing your charging off-peak such that you're not actually adding to the emissions that would otherwise be emitted by idling power plants. (Or if you live in an area with good hydro/nuclear and the like.) Of course, that's not really transparent to the electricity user in most cases.