Like you posted above, some electric companies add other per kWh charges that can add up. In my case the "Price to Compare" is currently 0.113060/kWh. the "other" charges adds another 0.63505/kWh. Using only the "Price to Compare" a full charge would cost me $1.71. When I include "Price to Compare" and the "other" charges that same full charge costs $2.67. My electric company also complicates it further by increasing their "Price to Compare" in the fall and decreasing it in the spring each year. Funny how the decrease in the spring is less than the increase from the prior fall.
Just curious, how are you measuring the kw used to charge your R4P?
I consistently see 15.1 kw when charging from 0 miles on the Kill-O-Watt meter that I use to monitor my charging electricity usage from my 120V outlet. I use the Departure Time charging feature so my R4P doesn't stay connected to the K-O-W meter for too long after it reaches a full charge. Maybe I just have a less efficient setup at home or my K-O-W meter is not measuring as accurately as it should.