Do Electric Cars Pencil Out?

A good way to think about what they’re trying to take away from us is to consider what ten gallons of gasoline weighs.

The figure is about 63 pounds, each gallon weighing just over six pounds. That 63 pounds of liquid energy will power a piston-engined car that averages 30 miles-per-gallon about 300 miles. 

A standard issue Tesla Model 3 goes about 263 miles on the solid-state energy contained in more than 1,000 pounds of battery pack. To put this in liquid-energy equivalent, 1,000 pounds of gasoline would be about 158 gallons of regular unleaded. That quantity of fuel would be enough to power the 30 MPG piston-engined car in our example above some 4,740 miles.   

Which is more “efficient”?

Interestingly, it the piston-engined car also travels farther as it consumes the liquid energy it carries, because it carries around less weight as it burns up its fuel supply. The electric car, on the other hand, is just as heavy when it is fully charged as it is when it is fully discharged. 

There is also no “energy penalty” for storing liquid energy. So long as the tank isn’t leaking, there won’t be less energy available when the piston-engined car’s owner wishes to drive somewhere – even if he left the car sitting for a month after having pumped in those 10 gallons. They do not evaporate or become less energy-dense. The tank requires no energy to preserve the energy it contains.

Electric car batteries, on the other hand, consume energy even when their energy isn’t being used . . . to power the car. But it is necessary to power the heater that maintains the temperature of the battery, which must be kept above a certain threshold in order to avoid damaging it and to maintain its capacity to receive a charge. Which it will require, after sitting for a month – unless it was hooked up to a charger, using energy that way.

More so, if it’s very cold out.

How about cost-per-mile? 

It is cheaper to charge up an electric car than to refuel a piston-engined car.

A Tesla 3 with the standard 50 kilowatt-hour battery costs about $10 to fully recharge; equipped with the upgrade 82 kilowatt-hour battery and the cost to fully recharge goes up to about $14. This is still much less than the roughly $32 it takes (at current per gallon cost of about $3.20) to buy ten gallons of liquid energy.

But is it cheap enough to make up for the cost of the electric car, itself?

A Tesla Model 3 with the 263 mile battery pack lists for $41,990. Excepting its electric drivetrain, it is otherwise similar to other small sedans such as the Audi A3, which lists for $33,900 – a difference “up front” of $8,090.

The Tesla goes 262 miles on about ten dollar’s worth of solid-state energy. The A3 goes more than 400 miles on 14.5 gallons’ worth of liquid energy (more than 500 miles on the highway) which costs its owner about $46 (at $3.20 per gallon).

To travel the same distance as the A3, the Tesla would have to receive an additional $5 or so of kilowatt-hour-equivalent energy, bringing the savings down to about $31 to travel roughly the same distance per charges in the Tesla vs. tankful (singular) in the Audi.

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