The average residential cost for electricity varies somewhat throughout the states, and varies greatly particularly in Hawaii where the costs is 37.53 cents per KWH.  That cost is almost 2-1/2 times higher than the 15.27 cents per KWH price in California; not that California is not a bargain state when it comes to residential electricity costs.  The real bargains are in states like Idaho and Washington whose electric rates make the rates throughout the rest of the country look like highway robbery.

We obtained our data from the U.S. Department of Energy.  It reveals the average cost of residential energy as of October 2011.  Using this data, we were able to calculate an estimated cost to charge all 3 battery-versions of the Model S.   We can’t truly account for cost per mile, because that will largely depend on your driving habits and the type of driving you do.  If you aren’t already aware,  the 160, 230, and 300 mile ranges on the Model S are based on an estimated range for driving at 55mph.  However, if your driving is mostly Highway at 65 or 70mph or you live somewhere with lots of hills, then your can expect less range and thus somewhat higher costs.  Just for the sake of comparison, we did calculate an estimated cost per mile (in cents) for each state as well.  Your cost per mile as I mentioned, will vary based on your driving habits and the topography of your roads.  Also these are aggregate costs per state.  Your individual cost per KWH is likely different in your city and could thus be somewhat higher or lower. Check your electric bill for your rate.  Your electric company may offer discounts for charging during non-peak hours or penalties for the opposite, so this too will vary your charging costs.

In the table to the left, we show costs for a full charge for each of the 3 different battery capacities for the 2012 Tesla Model S.  This cost is based on charging up your battery from zero to full.  We know this is unlikely since we’ll all be enjoying “topping-off” our charge from whatever charge was left when returning home to full for the most part.  However, this provides you an estimated cost per full charge and per mile based on the average in your state.

If you consider an ICE (Internal Combustion Engine) or gasoline-fueled car that offers 15mpg or one that offers 30mpg, you can see that the cost per mile is dramatically cheaper in the Model S.   Based on a price of $3.75 for gasoline, a 15 mpg vehicle will incur a cost of 25 cents per mile, while a 30mpg vehicle will incur a cost of 12 cents per mile.  So clearly, your electric billing rate determine what your potential savings may be.  This however, does not consider depreciation, maintenance, and repair costs.  For more information on that, please see Teslanomics. 

Considering these costs based on your electrical rate is important, however in gauging your potential savings because if you live in a state such as Hawaii, your cost per mile at 9.38 cents is still almost 25% cheaper than an ICE that offers 30mpg at a cost per mile of 12 cents, but not as economic compared to rates in other states.