How are cars powered by electricity made from coal less environmentally damaging than cars that burn gasoline?
In: Technology
Because big power stations are wayyyy more efficient at capturing heat than small engines.
Your run of the mill coal plant runs at 35-40% efficiency with newer fancier ones being up at 45%. Most car engines are in the 35% range with [45% peak efficiency(not sustained) being record breaking](https://phys.org/news/2019-06-efficiency-gas.html) but they throw away their energy every time they brake so the regenerative braking of the electric car adds several points back to the overall system efficiency.
A car that gets 40 mpg on a traditional gasoline engine will give off 136 grams of CO2 per kilometer. A Tesla model 3 uses 0.1625 kWh/km. Taking those two numbers our question comes down to what fuel sources output less than 837 grams of CO2 per kWh produced.
[Luckily the EIA actually has that data for us, and 1 Million BTUs turns into 293 kWh](https://www.eia.gov/environment/emissions/co2_vol_mass.php) so we can see that if 100% efficient even the crappiest Anthracite Coal would make 317 grams of CO2 per kWh. Our target is 837 g/kWh so we just need the overall system efficiency to be 42.5% (including regenerative braking) to beat out a 40 MPG car, looking at Coal (All Types) you need just 38.7% which is easily achieved.
As soon as you add a single Combined Cycle Natural Gas plant in there at 60% efficiency the electric car races ahead in efficiency
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