Out of curiosity, I did some calculations for the three major drivetrains for vehicles, gasoline, gasoline-electric hybrid, and full electric, to see which was cheaper in cost per mile, now that gas prices where I am (in Memphis, Tennessee) have reached $4.10 per gallon.
It’s rather difficult to compare gas and electric directly, because the pricing structure for electricity is somewhat complex. For example, Tesla’s Supercharger network prices are either expressed in minutes of various “tiers” of charging, or in kilowatt hours (kWh). Supposedly this is because selling electricity in kWh is reserved for electric utilities in some locations.
For electricity, our local municipal utility, Memphis Light Gas and Water (MLGW), charged me $0.109 per kWh on my most recent bill. But utilities also sometimes have a minimum, or base charge, even if your house is unoccupied, so pricing does vary based upon use.
The Tesla Supercharger here in Memphis bills in two tiers ($0.14 per minute for Tier 1, and $0.38 per minute for Tier 2). The Supercharger begins charging at the faster, higher price, and switches automatically to the lower price as the car’s battery gets close to the capacity setting the user has chosen. Tier 2 is supposed to be for charging at between 60 and 100 kW, with Tier 1 for below 60 kW. The various tiers of charging are also expressed in “miles per hour” in terms of range being added to the battery. For example, Tier 2 charging proceeds at about 253 miles per hour, while Tier 1 is more like home charging on 120VAC, which proceeds at about 2 to 5 miles per hour. Charging at the Supercharger works out at about $0.081 per mile. Charging at home takes a lot longer, particularly if you’re using regular U.S. wall voltage of 120V, but it works out to be a lot cheaper, say about $0.036 per mile. Looks like Tesla’s got a pretty good source of revenue in its charging network.
There’s an even cheaper alternative at Shelby Farms, the huge suburban park here (which in a past life was the Shelby County Penal Farm). MLGW (among others) spent $500,000 on a grid-tied “solar assisted” vehicle charging pavilion which has 10kW of solar panels on its canopy. It’s free and open to the public during hours the park is open (dawn to dusk), and charges at a rate of about 30 miles per hour (comparable to the speed you’d get plugging into your 240V clothes dryer outlet at home). Given that it has 10 spaces, each of which can supply up to 6kW, and only 10kW of solar panels, you can’t say for sure that your car is charging only from the sun, unless you’re the only one there. But being a grid-tied system, if nobody’s using it, it’s providing electricity back to the grid.
In Tennessee, thanks mostly to the Tennessee Valley Authority (TVA), over 60 percent of our electricity is generated from non-fossil fuel sources, primarily nuclear and hydroelectric power.
How does the cost per mile for an all-electric vehicle like the Tesla Model 3 compare to gasoline only vehicles, and gasoline-electric hybrids (leaving aside the substantial differences in purchase price of the cars themselves, and total-cost-of-ownership calculations)?1 The advertised miles per gallon rating of a typical gasoline powered car, like the Toyota Camry, is 26 miles per gallon, while the miles per gallon of a Toyota Prius gasoline-electric hybrid is around 56 miles per gallon.
For the 26 m.p.g. Camry, multiplying its fuel efficiency by the cost per mile of electricity from the Tesla Supercharger produces an equivalent gas price of 26 * $0.081 = $2.106, or about $2.11. For home EV charging, the equivalent gas price would be 26 * $0.036 = $0.936 or 94 cents a gallon! (We’ll just ignore the cost of charging at Shelby Farms, because you can’t beat free. You also can’t leave your car sitting there all day, as that kind of defeats the purpose of having a car.)
For the 56 m.p.g. Prius hybrid, multiplying its fuel efficiency by the cost per mile of electricity from the Tesla Supercharger produces an equivalent gas price of 56 * $0.081 = $4.536, or about $4.54 a gallon. Given that the current gas price in Memphis is only(!) $4.10, the Tesla has some ways to go before beating the Prius on cost per mile, if you charged solely from Tesla’s Supercharger. However, running the same calculation for home EV charging, the equivalent gas price in the Prius comparison is 56 * $0.036 = $2.01 a gallon.
The Prius’ gas-electric hybrid powertrain has a big advantage in range over the Tesla Model 3, which, even in its pricy long range 83 kWh battery version, has a range without recharging of 353 miles by the U.S. Environmental Protection Agency’s calculations, while the Prius can go over 630 miles on its 11.3 gallon tank, without the need to stop for many minutes to recharge. For long-distance driving in this era of high gas prices, the gas-electric hybrid powertrain still has an edge, in both cost per mile, and convenience.
And obviously, 56 m.p.g. beats the 26 m.p.g. of the gas powered Camry by a long run…
I picked the Tesla primarily to give electric the "worst case scenario." It's expensive because it's a lot fancier than it necessarily needs to be (lots of AI for the autopilot capability, for example). The price differential with, say, a Nissan LEAF (perhaps the most developed electric only vehicle) is considerably less (the model currently featured on Nissan's website has an MSRP of $37,400, and they list a starting MSRP of $27,400). My gas-only comparison Toyota Camry has a starting MSRP of $25,395, with a hybrid version (no doubt incorporating some of the Prius technology) starting at a bit more than $2000 extra, and in line with the LEAF. You can load up hybrids and electrics with technology and options that raise the price (as Tesla has done), but the price differential isn't that much anymore, if you compare like-to-like.
Hybrids are considerably more complex, because they have both gasoline and electric systems, but they do save some on maintenance because they don't use the brakes as much, due to regenerative braking, and don't stress the gasoline engine as much, because it's not running constantly. Electric only vehicles (as long as they're not full of extra technology, like the Tesla) tend to be simpler, since you've eliminated the need for maintaining the gas engine: no tune-ups, no oil changes, etc. But it all comes down to what you actually need for the driving you do.