2 cents x 24 hours = 48 cents, x 30 days = $14.40 x 12 months = $172.80 in a year. My rates are $0.08/KWh for step 1 ($0.11 step 2), that's not including transfer and usage fees which is $0.17/day.
You have cheaper rates than I do, so if your boxes are pulling 24W combined there is no way they cost that much per year.
Where is the 2 cents per hour coming from?
24 watts * 24 hours/day = 576 watt hours or 0.576 kWh/day
11 cents/kWh * 0.576 kWh/day = 6.336 cents/day
6.336 cents/day * 365 days/year = 2312.64 cents/year, or $23.13 a year.
You don't include transfer/usage fees in that since you pay that regardless of the cable boxes.
VirtualLarry is probably at least partially right about usage, maybe when running they are pulling more than 24W combined and that 24W is only at idle.