Old appliances, particularly refrigerators and freezers, suck so much power off the grid that states and utility companies often offer consumers incentives to replace them. For example, at the time of this writing ComEd was offering $50 to customers for each purchased Energy Star-certified refrigerator, clothes washer, electric clothes dryer, and freezer.

But from a purely pragmatic money-saving perspective, the expense of buying new appliances is seldom covered by the energy savings you get. If you replace an old, inefficient clothes washer with an Energy Star-certified model, you might save $40 to $50 per year in energy and water savings—which means a new model that cost $750 or more would have to be used a long time for utility-bill savings to cover its cost. Energy Star-certified dishwashers tend to save only about $20 to $40 a year on electricity and water compared to non-certified models. Even upgrading to a highly energy-efficient refrigerator doesn’t make sense unless your old model is ancient.

On the other hand, if your existing appliance needs repair, determine the cost of replacement minus expected energy savings versus the cost of the repair. Calculations on the Energy Star website let you compare annual operating costs of efficient and inefficient appliances according to how much you use them and how long you expect the new unit to last, among other variables. (When doing this math, make sure to factor in any rebates you can get.)

Of course, many consumers might want to switch to energy-efficient appliances to minimize the amount of energy their homes use and reduce their contribution to pollution and their carbon footprints.

The following tips from Energy Star will minimize electricity usage, regardless of your refrigerator’s age:

  • Set the temperature of your refrigerator to 35° F and freezer to 0° F.
  • If possible, position your refrigerator in a cool place, away from your oven and dishwasher, and out of sunlight.
  • To allow air circulation, leave a two- or three-inch space between the back of your refrigerator and the wall.
  • Make sure there’s an airtight seal when you close refrigerator and freezer doors. When seals wear out, replace them.