I don't know about your area, but in my area electric bills are quite complex in their calculation of charges.
It is not just a simple rate. They allow so much at a lower rate for electric water heaters. Then a reduced rate for the first so many kWh used. Then a higher rate after that. Then there are transmission charges which I think are the same for all electricity used. Then they tack on taxes and assorted fees what are a percentage. But a percentage of what? Lower percentage for the first so many kWh used then higher after that or straight percentage across the board of all charges including transmission charges?
Then depending on who you are (home, farm, business, industry), you get a different rate!
This has evolved over time. At one time they had a separate meter for water heaters which got a lower rate. Then they removed these and just gave everyone a reduced rate for so many kWh's for water heaters. Then someone said they should charge a lower rate for "basic" usage keeping poor people in mind. Etc., etc.
Then you may get a renter who will dispute your calculation of the charges based on how it should be calculated...
I would gladly install a separate electric company meter no matter what it cost!