If you know the wattage and price of your electricity then you can figure out the cost over time with this formula:


Energy Cost to run =   

wattage x cost per kilowatt hour x average rated life  
                                   1000

Note the cost per kilowatt hour is available from your utility. For example, the cost to run a 100 watt lamp with an average rated life of 750 hours at a rate of .10/ kWh would be:  

Cost =   100 x .10 x 750   which works out to be $7.50.  
                     1000    

To purchase, please visit The Energy SuperMarket