An average HD draws 6-8W in an active state (writing/reading). Let’s say it is 10W
10W * 24 h = 240 Wh / day
300 Wh * 30 days = 9,000 Wh / month = 9 kW / month
10 kW * $0.1-0.4 = $1 - $4 per month
Not sure, whether I should bet on my math, though.
2 Likes