Refrigeration provides another case in which targeted research produced remarkable results: a reduction of more than two-thirds in the energy consumed by the household refrigerator during the past 30 years. In 1974, the average consumption per unit was 1,800 kilowatt-hours per year, and average sizes were increasing as well. At that point, a joint government-industry R&D initiative began looking for more efficient compressors, as well as improvements in design, motors, insulation, and other features.
The effort began to pay off almost immediately. By the early 1980s, electricity consumption per refrigerator had dropped by one-third and new developments kept coming. Even the changeover from ozone-threatening chlorofluorocarbons (CFCs) did not impede progress. Further design enhancements and tighter government standards since 1990 have saved the nation an estimated $15 billion in total electricity costs for home refrigerators over the entire life of the appliances.
Today there are still enormous opportunities for efficiency gains across a wide range of products and processes. One area regarded as particularly ripe for improvement is lighting, which accounts for 18% of all electricity use in the United States and 21% of the electricity for commercial and residential buildings. Major research efforts are in progress to reduce those costs by using the same technology that now creates the glowing lights on appliances: the light-emitting diode (LED).
LEDs are “solid-state” devices made of materials similar to those in computer chips. They produce illumination by allowing electrons to flow across an electrical junction (the diode) and drop into a lower energy state, releasing the difference as light. LEDs generate relatively little heat, last 100 times longer than an incandescent lightbulb, and convert about 25% to 35% of electrical energy to light, as opposed to about 5% in a conventional incandescent bulb. Additionally, they do not require bulky sockets or fixtures and could be embedded directly into ceilings or walls.