“We are never home – we couldn’t have used this much electricity.”
Or, “We went on vacation for two weeks and our electric bill shows barely a drop in usage.” We often hear comments like these, especially in summer. How can electric bills scarcely change when a house is empty for most of the billing period? Here are some things to consider.
First, the modern house is increasingly equipped with appliances that consume electricity. Electronic devices that you “set and forget” have a constant draw of power and use a considerable amount of electricity each month. The instant-on features on televisions, DVRs, computers, satellite dishes, and TV’s consume approximately 2 to 10 kilowatt hours of electricity each ($0.20 to $1.00) per month. Electronic gadgets with transformers use 2 to 4 kilowatt hours a month and a night light can use 10 to 20 kilowatt hours.
Also, did you know that a vacant house with a thermostat set at 55 degrees may use more energy than an occupied house set at 65 degrees? Lights, cooking, baths, clothes drying and other “people” activity help to raise the temperature in a home. An empty house’s heating system must work harder to maintain the 55 degree temperature.
The refrigerator (the second largest energy user in the average home) also works harder in a shut-up house. Door opening accounts for less than 20 percent of a refrigerator’s energy use; the appliance is much more sensitive to the room temperature around it. A house that is left without any ventilation will raise the kitchen temperature and increase the refrigerator’s energy use 50 percent during the summer.
Most vacationers do not like to pull the plug on major appliances because of the trouble of connecting, reconnecting and resetting the data. But there can be big savings if appliances are unplugged while the house is empty.
Your first thought might be to empty the refrigerator of perishables and then go on vacation. If so, you should reconsider. Leaving a refrigerator almost empty will cause it to work harder and actually increase its energy consumption. It would be better to totally empty the refrigerator and set the thermostat to the highest (warmest) setting. Doing that should lower your refrigerator’s energy use by about 40 percent without causing any mold or mildew that would occur if you unplugged it. Many people also have a second refrigerator or freezer in the basement, garage or back porch. Depending on the refrigerator’s efficiency, assume the unit consumes 40 to 150 kilowatt hours ($4.00 to $15.00) per month. Automatic defrost freezers will use approximately 120 to 140 kilowatt hours ($12.00 to $14.00) per month.
Another appliance that continues to work while you are gone is your water heater. The energy use for standby water heating is approximately 50 to 150 kilowatt hours ($5.00 to $15.00) per month. In-sink water heaters also continue to use electricity – approximately 8 to 20 kilowatt hours ($0.80 to $2.00) per month.
Other energy users include:
- Home computers cost about one penny an hour to operate. If left on all day, every day, that adds up to more than $7 each month.
- Fish aquariums use between 10 and 150 kilowatt hours ($1.00 to $15.00) per month.
- Pool and spa pumps use 25 to 200 kilowatt hours ($2.50 to $20.00) per month.