ICE vs Supercharger comparison table

[Chrushev]

Not sure if a tool like this exists elsewhere. I didnt do too much searching. I made this for personal use, but posting here in case it helps others.

My situation. I have a Model Y and a PHEV. I can get 40Mpg on PHEV. I wanted to see at what Supercharger rates it would be more efficient to take my PHEV instead of the Model Y. Important thing of note here, EVs are extremely cost effective if you can charge at home or at level 2 chargers. So this is mostly applicable for road trips, where only source of propulsion is superchargers and gas stations. Of course charging at start/destination would change the calculation as well (towards the Tesla).

Tables can be used in various ways. For example, if you only have a Tesla, but are curious if its more expensive per mile than current gas prices you would do the following:
1) Use right table, find row with charge cost (around here 58c/kw), then find column with your driving efficiency (I get about 270 watt/mile). So when we look at where these cross, I get 15.7 cents per mile
2) Now on the left table find current gas prices ($5.20 around here), I can see that Id have to have a 35MPG car or better for ICE to be more cost effective. This is same thing as saying my Model Y is as cost effective (again not counting much cheaper home/level 2 charging) as a 35MPG ICE.

Check what SuperCharger rate would be a good deal vs my PHEV (40MPG)
1) Left table find current gas price and PHEV MPG cross section. (13 cents per mile).
2) On the right table check my Watt/Mile column (270watt/mile) and go down until I get to 13 cents. Then look at the row name. 48 cents. So charging at 48 cents or cheaper makes Model Y more efficient for me (this will depend on your driving watt/mile efficiency). This does mean that with current gas prices it is cheaper for me to use PHEV over Model Y if I Superchargers are my only source or charge.

You can use it to see how much its costing you to charge at home (per mile)
1) Find per/kw rate on the right table (lets say 12c/kw), then column with your driving efficiency (lets say 270watt/mile). We see that it costs you 3.2 cents per mile.
2) You can then see that your 40MPG ICE would cost the same if gas was $1.30 per gallon. Which makes Tesla extremely cost efficient.

Anyways, hope its useful to someone else.

Tesla Supercharger vs Gas comparison

Data Cost Per Mile,Watt Hour per Mile Gas Price Per Gallon,20 MPG,25 MPG,30 MPG,35 MPG,40 MPG,45 MPG,50 MPG,55 MPG,60 MPG,Charger Cost per kWh,150.00,160.00,170.00,180.00,190.00,200.00,210.00,220.00 $1.00,$0.0500,$0.0400,$0.0333,$0.0286,$0.0250,$0.0222,$0.0200,$0.0182,$0.0167,$0.10,$0.0150,$0.01...

docs.google.com

 

[swaltner]

Nice, but please use valid units.

“Wh/mile” or “Watt Hour per Mile”
“Charger Cost per kWh”

I tend to let these errors slide in conversation, but not when people publish documentation.

 

[RTPEV]

It's a nice table, but the next evolution should be a form that accepts input such as:

1. EV efficiency (Wh/mile or miles/kWh)
2. Gas efficiency
3. PHEV range
4. Cost of gas
5. Cost of DC fast charging
6. Cost of L1/L2 charging
7. Opportunities for charging en route or at destination
8. Miles driven en route versus at destination

All of these things can shift the balance to/from the BEV. In particular, the ability to fully charge overnight while en route or charge at the destination side and run completely on electric while there is huge and I'm not sure people take that into account when they are making the decision that 15-30 extra minutes spent charging (because apparently they have steel bladders) on a 12 hour trip is going to ruin their trip, so they'll just take the gas car instead. Yeah, and now they've got to pay for gas for all the running around they do at the destination side. Whereas if I can charge at the remote end (for presumably free or low cost), now I can have cheap and easy transport there, and I can start my trip home with a full battery. And if you can get free or cheap charging at hotels en route, not only does that help with costs, but it even helps the steel bladder types who will probably be able to skip that first stop in the morning when most people don't yet need to stop.

 

[avs007]

Well, the math is actually pretty simple, so if you wanted to see what the break even point for gas is, it's pretty easy...
Start with your WH/mile efficiency value, and multiply that by your charging costs per kWh... So for example, if you average 298 wh/mile, and pay 58 cents per kWh at the SC, that would mean it would cost you $172 to drive 1000 miles.

So now divide 1000 miles, by your average fuel economy for your car... So in my case, my MDX averages 17 mpg best case, which means it'll take 58 gallons of gas... Take the $172 dollars and divide by 58 gallons, and the break-even point is $2.96 / gallon. That means if gas is cheaper than that, it'll be cheaper for me to drive my MDX, otherwise it'll be cheaper to drive my Y, if I'm paying 58 cents / kWh. And I just drove thru California a few weeks ago. Gas was over $7/gallon at a few places near Shasta.