Amaze your friends with your cost of energy knowledge.
Here is a quick top of the head calculation you can make on how much you are spending on operating any electrical device.
Rule of Thumb:
1 Watt = $1 per year for 24hrs/day 365 days operation*
Example
Step 1: Note the wattage on the device. Example : 60W light bulb
Step 2: Calculate - If the bulb was on 24hrs/day, 365 days per year
you would spend $60 per year.
In other words:
60Watts = $60 per year.
If the bulb is not on all the time:
If the bulb is on 12 hrs (1/2 day) divide by 2 or $30 per year
If the bulb is on 4 hrs per day (1/6 day) divide by 6 or $10 per year.
to put it in mathematical terms:
$ Per Year = Hrs per day/24 x Watts
* This is approximate and assumes $.11 per KWhr electric rate.