EV Street - Electric Vehicles for Dinosaurs

Electric Vehicles have come of age. But, it's going to take a revolution to make it happen.

Tuesday, December 11, 2012

Nissan Leaf electric costs - first month, the answer to your biggest question.

(If this is your first visit to this blog, I recommend reading the previous post first)

People have a hard time wrapping their brains around the low cost on the electric bill. Several people in my office said, "well let's see what your first electric bill looks like." OK, my first electric bill is in. It was a $32 increase. The car has been driven 4 days short of the billing period. We put 922 miles on the car in that period. Yes, that's about $0.035 per mile.

In that month, a lot has changed with regards to the decision to get this vehicle. Mostly, the price of gas. When we got the car just a little over a month ago, gasoline was $4.20 per gallon here. I just filled up an SUV yesterday for $3.45 per gallon. That's a pretty big drop in just a month. At 25MPG which is the average for the gasoline cars we drive, that same mileage (922) would have cost about $155. But today, that cost would be $127.

OK, now to answer the question some of you may not understand, "how can it be that cheap, I thought gasoline was cheaper per unit of energy." The answer my dear friends is yes, gasoline is cheaper per unit of energy. There are about 40 KWH (Kilowatt hours) of energy in a gallon of gas. My car's battery pack will only store about 24 KWH. So imagine a gas tank on your car that was a little over 1/2 a gallon! Granted, the range is less. I know, I still haven't answered the question. The answer, is efficiency. The leaf (for us) gets about 3.5 miles per KWH. Our other gasoline cars get .625 miles per KWH. Yes, that is how inefficient our gasoline cars are (and probably yours too).

Why you ask, if they are both similar size and weight? First answer, your ICE engine spews about 60-70 % of its energy out the tailpipe and through the radiator in heat. Second, the energy it is able to turn into mechanical energy goes through a less efficient transmission before it gets to the tires. Third, when I step on the brakes, part of the energy spent accelerating the car is returned back to the batteries, in the gasoline cars, it all goes up in heat on the brake rotors.

So, all things remaining constant, if the leaf did run off gasoline, and the conversion of gasoline energy were perfect, it would get about 140 MPG.


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