How are cars powered by electricity made from coal less environmentally damaging than cars that burn gasoline?
In: Technology
What cars are using coal as a source of power?! We haven’t used coal for vehicles since steam technology in the late 1800s.
There’s more energy sources than *just* coal out there and the percentage of energy made by renewable, greener sources is growing every year.
And plugging your car into an outlet for a few hours uses a lot less net energy than burning gallons of gasoline in a traditional combustion engine.
Electric cars don’t burn coal; coal-fired power stations do. If your electricity grid is coal fired then obviously going to electric cars doesn’t solve your emissions problems but it does mean that moving to renewable electricity will help. In fact electric cars are a good fit for solar and wind generation because we can to some extent choose to charge the cars when they have surplus power and not during peak load.
Because coal is only one electricity source among many – other sources (even natural gas) have a significantly lower carbon footprint by comparison. The practical consequence of this is that even if you account for the contribution of coal, [99% of the US’ population](https://blog.ucsusa.org/dave-reichmuth/new-data-show-electric-vehicles-continue-to-get-cleaner) live in places where driving a Model 3 will yield lower per-mile emissions than even a Prius. In Europe, EVs [also realize significantly lower lifecycle emissions than diesels](https://www.transportenvironment.org/press/electric-cars-emit-less-co2-over-their-lifetime-diesels-even-when-powered-dirtiest-electricity).
77% of electricity comes from sources other than coal so I’m not sure why you cherry picked that.
https://www.eia.gov/energyexplained/electricity/electricity-in-the-us.php
1) Power plant are far more efficient than combustion engine.
2) Coal is not the only source of electricity, but it’s true that depending on where you live the different in emission could be less attractive.
Here a good video about the subject.
[https://www.youtube.com/watch?v=6RhtiPefVzM&t=602s](https://www.youtube.com/watch?v=6RhtiPefVzM&t=602s)
It’s to do with efficiency. Internal combustion engines in cars are less than 40% efficient at extracting energy from petrol/gas. For every 100 joules in the fuel, most engines lose more than 60% in heat, noise, and vibration via the engine itself and the drive train (gearbox etc).
Coal plants are simply more efficient than that. Renewable energy is better still.
23% of US power comes from coal, and this has been a on steady decline for years so it’s become less and less of a problem.
Regardless producing power on a large scale using fossil fuels is far more efficient than burning fuel in individual engines in cars.
So 1 power plant making power for 100,000 cars is more efficient than 100,000 individual gas engines.
But to address the elephant in the room, yes having more efficient sources of power generation AND electric cars would be magnitudes more efficient.
You also have to factor in the environmental pollution resulting from the production of electric cars like mining Lithium and waste. Overall electric cars are better than gas powered cars but there’s more work to be done to make things more eco friendly.
Power plants can be run on a variety of fuels, and do a far better job of converting those fuels into electric energy than a combustion engine does converting one specific fuel into mechanical energy.
If you simply burned the gasoline in a power plant it just might end up being more efficient. Adding renewable energy and garbage incinerators reduces the environmental damage further.
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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