I used 5% b/c that's what I learned in b-school and they still use 5%.
I live in California/Silicon Valley. So gas and electricity is set accordingly. Feel free to copy the model and plug in your own numbers. I didn't take into account TOU rates or solar (I might add a solar tab later). And while I charge most of the time at work for free, I assumed in this model that all of my charging was at home.
The price for the new Model S is for an S85 in blue metallic w/ obeche matte, tan leather, pano, supercharging, twin chargers, rear-facing seats, and parcel shelf.
As omgwtfbyobbq on TMC noted, all of these numbers - including NPV - should technically have a negative sign in front of them. I was just lazy and got tired of typing in negative numbers everywhere.
Electricity is currently at 3 mi/kWh or 333 Wh/mi. omgwtfbyobbq also noted that the draw from the wall might be higher. I'll adjust it when I get a good number. Feel free to suggest one. Update: TMC folks suggest using EPA figures to account for wall draw. More below.
Combined EPA ratings for Ody and Tesla. I used the combined rating for the Ody and a lower-than-EPA rating for the Tesla to be conservative.
For Tesla residual, this McKinsey article is one reason for the $30K value in 2022 (forecasts $/kWh falling from $600 in 2012 to $200 in 2020, or $17K for an 85kWh battery).
And, as noted in the previous tab, because I was lazy and for other reasons, I left out insurance, and didn't try to quantify safety, HOV lane access, cargo space, and other features.