How much does a Tesla X cost to drive per mile at residential California electric rates?The rule of thumb for from Tesla's website forum is 3 miles per KWH , I've found this to be true for the Chevy Volt as well.
Californian's can charge their EV's at night for 3.7 cents per KWH (for the first 180 KWH in the summer) on the E-6 rate plan, rates go up based on usage. So for the first 540 miles of the month, the cost is about 1.2 cents per mile, or about $7. If you drive around 1000 miles per month, (12,000 miles per year) then you might want to budget as much as $20 per month in electricity costs.
This is possible thanks to PG&E's Smart meters. Residents pay a higher rate per hour during the day, something around 30 cents per KWH, for the privilege of charging their cars at the cheaper rate at night. This also helps PG&E balance out the demand for power between the nights and days, so it's a win for the utility, and a win for the EV driver.