Electricity is expensive! Currently the cost per kWh is around 7.4 cents. Don’t be fooled, you still pay a delivery charge and other fees, tax and sometimes even retail fees. This brings the actual cost somewhere around 15-20 cents per kWh.
Using this calculation we can determine the monthly cost of using a single watt:
1 watt * 24 hours / day * 30.5 days / month / 1000 watts / kWh * $0.15 / kWh = $0.11 per month
1 watt * 24 hours / day * 30.5 days / month / 1000 watts / kWh * $0.20 / kWh = $0.15 per month
…and yearly this translates to roughly $1.30 to $1.80…per watt!
Who would have thought that a $1 100 watt light bulb could cost over $100 a year?
Here is a list of some devices which I have measured the power consumption using a cheapo power meter:
|Device Name||Min. Watts||Max. Watts|
|Cisco RV042 Dual WAN Router||5||7|
|Cisco DCP3825 Cable Modem/Router(bridge mode)||7||9|
|Netgear GS605 5-port Gigabit Switch||5||7|
|Aztech DSL Modem (no sync)||2||2|
|Motorola SB5101 Cable Modem (no sync)||3||4|
|Dlink DGS1005D 5-port Gigabit Switch||3||4|
A worst case estimate for the yearly cost in dollars would be determined by multiplying the average power consumption by a factor of 2.