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In which I show the math.
The claim is often made that e-cars like the Tesla help the planet. It's also cheaper to operate since charging a Tesla's batteries is cheaper than a tank of gas.
But to the greenies among us the relevant comparison isn't the cost of fuel but carbon emissions.
The electricity we use to charge an e-car is on the average made up of this mix of power sources in the US:
Coal - 34% , Carbon emitted by coal - 909 g per kW-h.
Natural Gas - 39%, Carbon emitted by natural gas - 465 g per kW-h
Oil - 0.6%%, Carbon emitted by oil - 821 g per kW-h
Solar - 1%, Carbon emitted by solar - 105 g per kW-h
Wind - 3%, Carbon emitted by wind - 13 g per kW-h
Nuclear - 20%, Carbon emitted by nuclear - 6 g per kW-h
A weighted average of the above gives us 499 g per kW-h
The Tesla Model S gets 3.22 miles per kW-h. That's 31.1 kW-h to go 100 miles, and thus 15.5 kg of carbon is emitted at the generator plant on the average to power this car for 100 miles.
For the Fusion, which gets 20 miles to the gallon, it would need 5 gallons to go 100 miles, which when burned emits 2.48 kg of carbon per gallon or 12.8 kg of carbon for 5 gallons to go 100 miles.
So an ordinary gasoline powered car that doesn't even have gas mileage that's very good emits less than the Tesla. It's just that the emission takes place at some place other than the car. The Tesla is causing the emission of as much carbon as a car that gets 16.5 miles per gallon.
For the Ford Hybrid Fusion, which gets 40 miles to the gallon, it beats the Tesla by quite a margin: 6.4 vs 15.5 kg of carbon emitted per 100 miles of travel.
Keep in mind that 1 gram of carbon equates to 3.66 g of carbon dioxide when making comparisons.
Any corrections of the math or questions about my sources for these numbers are welcome.
The power mix data comes from 1 kilowatt-hour · BlueSkyModel and Electricity Data Browser
The figure for Tesla electricity consumption comes from https://forums.tesla.com/forum/forums/how-many-kms-can-tesla-model-s-2013-travel-1-kwh
Ford Fusion mileage data comes from Ford ? New Cars, Trucks, SUVs, Hybrids & Crossovers | Ford Vehicles
Cost to charge a Tesla model S: https://www.tesla.com/models
Of course, this analysis leaves out the carbon footprint of building and disposing of the vehicles, but I suspect that would just leave the Tesla further behind.
And also, if you get your power from a company that uses 100% renewables, nuclear, or other low or non emitting power sources then you're golden if you own a Tesla and have the right to be a smug as you like. I know that in Houston I see a number of Teslas on the road, and most of the power in Houston comes from burning coal.
Also, compare the cost of charging the Tesla with 100 miles worth of electricity ($4.01) to the cost of 5 gallons of gas. There's no question that the Tesla is cheaper to fuel!
It doesn't look like Tesla is claiming that their cars help the planet by emitting no carbon. Instead, they talk about sustainability, which may be a valid claim if the switch from carbon fuels to renewables and nuclear continues. But we are not there yet.
The claim is often made that e-cars like the Tesla help the planet. It's also cheaper to operate since charging a Tesla's batteries is cheaper than a tank of gas.
But to the greenies among us the relevant comparison isn't the cost of fuel but carbon emissions.
The electricity we use to charge an e-car is on the average made up of this mix of power sources in the US:
Coal - 34% , Carbon emitted by coal - 909 g per kW-h.
Natural Gas - 39%, Carbon emitted by natural gas - 465 g per kW-h
Oil - 0.6%%, Carbon emitted by oil - 821 g per kW-h
Solar - 1%, Carbon emitted by solar - 105 g per kW-h
Wind - 3%, Carbon emitted by wind - 13 g per kW-h
Nuclear - 20%, Carbon emitted by nuclear - 6 g per kW-h
A weighted average of the above gives us 499 g per kW-h
The Tesla Model S gets 3.22 miles per kW-h. That's 31.1 kW-h to go 100 miles, and thus 15.5 kg of carbon is emitted at the generator plant on the average to power this car for 100 miles.
For the Fusion, which gets 20 miles to the gallon, it would need 5 gallons to go 100 miles, which when burned emits 2.48 kg of carbon per gallon or 12.8 kg of carbon for 5 gallons to go 100 miles.
So an ordinary gasoline powered car that doesn't even have gas mileage that's very good emits less than the Tesla. It's just that the emission takes place at some place other than the car. The Tesla is causing the emission of as much carbon as a car that gets 16.5 miles per gallon.
For the Ford Hybrid Fusion, which gets 40 miles to the gallon, it beats the Tesla by quite a margin: 6.4 vs 15.5 kg of carbon emitted per 100 miles of travel.
Keep in mind that 1 gram of carbon equates to 3.66 g of carbon dioxide when making comparisons.
Any corrections of the math or questions about my sources for these numbers are welcome.
The power mix data comes from 1 kilowatt-hour · BlueSkyModel and Electricity Data Browser
The figure for Tesla electricity consumption comes from https://forums.tesla.com/forum/forums/how-many-kms-can-tesla-model-s-2013-travel-1-kwh
Ford Fusion mileage data comes from Ford ? New Cars, Trucks, SUVs, Hybrids & Crossovers | Ford Vehicles
Cost to charge a Tesla model S: https://www.tesla.com/models
Of course, this analysis leaves out the carbon footprint of building and disposing of the vehicles, but I suspect that would just leave the Tesla further behind.
And also, if you get your power from a company that uses 100% renewables, nuclear, or other low or non emitting power sources then you're golden if you own a Tesla and have the right to be a smug as you like. I know that in Houston I see a number of Teslas on the road, and most of the power in Houston comes from burning coal.
Also, compare the cost of charging the Tesla with 100 miles worth of electricity ($4.01) to the cost of 5 gallons of gas. There's no question that the Tesla is cheaper to fuel!
It doesn't look like Tesla is claiming that their cars help the planet by emitting no carbon. Instead, they talk about sustainability, which may be a valid claim if the switch from carbon fuels to renewables and nuclear continues. But we are not there yet.
