Energy Efficiency



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Did you know that the average home spends about $2,000 on energy bills every year? Change to appliances that have earned the ENERGY STAR, and you can save $75 a year in energy costs, while saving the environment.

Save Energy, Save Money

When buying an appliance, remember that it has two price tags: what you pay to take it home and what you pay for the energy and water it uses. ENERGY STAR qualified appliances incorporate advanced technologies that use 1050% less energy and water than standard models. The money you save on your utility bills can more than make up for the cost of a more expensive but more efficient ENERGY STAR model.

For top performance, premium features, and energy savings, look for energy-efficient clothes washers, refrigerators, dishwashers, room air conditioners and dehumidifiers that have earned the ENERGY STAR. This mark may appear on the appliance, the packaging or the EnergyGuide label.

Learn more about ENERGY STAR qualified products.

Buy ENERGY STAR Products in Bulk

Do you purchase products in bulk for a company, institution, or other organization? Are you looking for energy-efficient products at competitive prices? If so, check out ENERGY STAR Quantity Quotes where you can get quotes on ENERGY STAR qualified room air conditioners, clothes washers, dehumidifiers, refrigerators, dishwashers, light fixtures, and light bulbs. ENERGY STAR Quantity Quotes is a free online service of the U.S. Department of Energy.

Existing Appliances

NorthWestern Energy provides the following energy-saving tips for your existing home appliances:

Clothes Dryers

  • Check your dryer vent occasionally. A clogged vent causes your dryer to consume more energy. All gas dryers must be vented outside.
  • Make sure your dryer is located in a heated part of your home. Dryers in an unheated area must warm incoming air, using more energy.
  • Use a clothesline when possible.

Cooling and Freezing

  • Set your refrigerator temperature between 37° and 40°F. If you have a refrigerator/freezer combination, set the freezer temperature between 0°F and 5°F. In stand-alone freezers used for long-term storage, set the temperature to 0°F. It takes about 15 minutes to get a good initial reading and then about 24 hours for a change in setting to take effect.
  • Inspect the seals around refrigerator and freezer doors. Replace these seals if they are cracked or if you can feel cool air escaping. To check the seal, place a dollar bill between the door and the cabinet of the refrigerator. Close the door. Pull the dollar bill straight out. You should feel some resistance. Test all around the door. If there are places of no resistance, replace the seal.
  • Defrost manual-defrost freezers regularly. Frost makes them work harder and wastes energy. Don't allow more than one-quarter inch of frost to build up.
  • Place refrigerators and freezers where they operate at room temperature. Compressors need to work extra hard when the refrigerator is in hot or cold areas such as porches or garages.
  • Turn off and safely store extra refrigerators, especially if they are older than 10 years. Older units use about three times as much electricity as new models.


  • Turn off lights when not in use. If fluorescent lights will be unused for 15-20 minutes, turn them off, too.
  • Consider installing motion sensors or timers on exterior lighting. Indoor occupancy sensors automatically turn off lights a short time after you leave a room and turn them on when you enter.
  • Replace traditional incandescent bulbs with compact fluorescent lamps (CFLs) where possible. CFLs have improved significantly in recent years. They are smaller and can fit almost everywhere standard incandescent bulbs are used. CFLs use about a third as much energy to create the same amount of light as incandescent bulbs, and they last 8 to 10 times longer. Choose a CFL with lumen output close to that of the incandescent bulb you use currently.
  • Avoid using long-life or extended-life incandescent bulbs. They give off less light than a standard bulb and use more energy.
  • Replace halogen torchieres with energy efficient CFL torchieres that operate at a much lower temperature, use less energy and are dimmable. Halogen versions can reach temperatures up to 1,000 F, creating fire hazards.

Space Heating

  • Check the amount of insulation in your attic, basement walls and crawl spaces and add more if needed. We recommend an R-value of 38 for the attic and 19 for walls.
  • Clean or replace furnace filters regularly.
  • Hire a heating and cooling expert annually to inspect and service your heating system to ensure it operates efficiently and safely.
  • Install a programmable thermostat that automatically sets heat back at night and when no one is home.
  • Change your thermostat setting in winter months to the lowest comfortable setting- 68° F for most people during the day and 60° F at night or when no one is home.
  • Close fireplace dampers when not in use. For more energy savings, plug the flue opening with a large garbage bag stuffed with fiberglass insulation; hang a long bright ribbon down from the bag as a reminder.
  • Wear a sweater or warm clothing on cold days instead of turning up the heat.

Water Heating

  • Repair leaky water faucets. 
  • Limit showers to five minutes or less. 
  • Only use dishwashers, clothes dryers and washing machines when they are full.
  • Install low-flow and faucet aerators and save about 18,250 gallons of heated water per year.
  • Set the temperature of water heaters to 120°F. Use a candy thermometer to check the temperature of hot water running from a tap.
  • Install an insulating blanket on your hot water heater. Follow installation directions.
  • Hot water pipes in unheated areas should be insulated. If located in a heated area, the first 10-feet of hot water pipe from the water heater tank should be insulated.
  • Choose energy-efficient hot water heaters when purchasing a new one. NorthWestern Energy recommends an energy factor of at least .59 or better for 40-gallon gas or propane heaters. New 40-gallon electric water heaters should have energy factors of at least .91. Larger water heater tanks will have slightly lower energy factors.
  • Turn your gas water heater thermostat to "pilot only" to save energy when you are away for several days. If it is an electric heater, turn it off. Write a note to remind yourself to turn it back on.
  • Drain water from the bottom of the tank at least every three months to avoid sediment accumulation and maintain energy efficiency. To drain the tank, open the drain valve at the tank bottom and allow the water to run until clear (one or two buckets of water usually will do).
  • Use cold water for laundry. Almost all detergents clean clothes effectively in cold water.
  • Skip the dry cycle on the dishwasher when possible. Open the door slightly so dishes dry naturally. This measure can save about one-half the power consumed in a normal cycle.

Other Tips

  • Use cold water to operate your food disposal.
  • Plant shade trees and shrubs on the sunny side of your house to cool it naturally. Plant coniferous (pine) trees on the north side to serve as a wind break.
  • Install window shades or curtains to keep the sun out in summer and let it in during winter.
  • Keep hot tubs and waterbeds covered when not in use.
  • When shopping for a hot tub or spa, look for built-in energy-saving features. These include good insulation all around-including the cover-the use of low-voltage LED (Light Emitting Diodes) instead of incandescent bulbs, and low-wattage pumps.
  • Install an outdoor-rated timer on the outlet for your engine block heater. Almost all engines need to be warmed for only about an hour, so a timer eliminates unnecessary heating.
  • If you have central air conditioning, set your thermostat to the highest comfortable temperature. Install a setback thermostat to reduce cooling when you're away or sleeping.
  • Shop for the highest SEER or EER rating possible on your air conditioning unit. The higher the number, the more efficient.

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