Using data from the Department of Energy (here and here), Mark Perry illustrates that household consumption of energy declined by almost 33% between 1980 and 2005, and household expenditures on energy per square foot declined by over 40% in the same period. This suggests “that American homes are becoming more and more energy efficient all the time.”
Energy efficiency has also increased for standard household appliances since 1980, according to data Mark Perry collected from Association of Home Appliance Manufacturers.
For a home refrigerator in 1980, its energy factor (EF, a standard measure of overall energy efficiency for appliances) was 5.59, and by 2008 the EF for refrigerators had increased almost three-fold to 15.50, for a 177.3% improvement in energy efficiency. The other standard home appliances in the chart above also had significant improvements in energy efficiency, from a 41.5% increase for the room air-conditioner, to a 91.4% increase for the dishwasher.
What should you make of this? Mark Perry writes:
These significant increases in energy efficiency for both our homes in general and also for the appliances that we have in our homes have happened gradually, but steadily, for many decades, and many of these improvements in energy efficiency probably took place without any government intervention, stimulus or rebate programs. The incentive to save money ensures that there will always be an incentive to become more energy efficient out of pure self-interest, since increased energy efficiency translates directly into monetary gain.