I pay approximately (it varies with amount used and the seasons) $1.16
Per kwh.
16 kwh x $1.16 per kwh = $18.56 to charge the battery.
$18.56 per charge divided by 25 miles = $0.74 per mile to operate the
Volt using the battery.
Looking at my utility bill I used 238KWH last month and was charged $23.62 or ~10 cents per KWH. You might want to double check those numbers or call your utility!