An external hard disk uses
approximately 4 to 8 watts; on average, it operates for about 8 hours a
day.
Enter the number of usage hours and power setting (in wattage), then click "Calculate"
to find the power consumption
of external hard drive using 8 watts for 8 hours
a day at EUR €0.31 per kWh. You will also see the running cost per hour, day, week, and year.