Every energy-using appliance has two price tags.We know the first - the purchase price . The second price tag is considered less in the purchasing decision,but is just as real;it is the operating cost of the appliance.The purchase price is like a down payment.You can think of the second price- the cost of energy as a series of monthly payments that last as long as the appliance operates.
For example,consider an electric storage water heater that costs approximately $700 to purchase and install. If electricity costs 10 cents per kilowatt-hour(kWh)and your family uses 225 litres(L)(59 gallons{{gal.}}) of hot water per day over a 10-year period,your energy costs in that period will be approximately seven times the cost of the equipment.
Natural Resource Canada