Rush Holt (from newsletter):
Energy Efficiency for Electronics
Not too long ago, appliances - refrigerators, air conditioners - consumed the most energy in our homes. In 1990, the United States established efficiency standards for appliances, resulting in significant energy savings. Setting standards is an especially effective way for government to achieve results. New refrigerators on average use 45 percent less energy than they did in 1990, while new washers use 70 percent less energy than a new washer in 1990. Additionally, the creation of the Energy Star program gives consumers the information to purchase appliances with even more efficiency than current standards.
Yet, in contrast to greater energy efficiency for home appliances, home electronics - televisions, video games - are taking up more and more energy. The International Energy Agency recently found that consumer electronics represent 15 percent of household power demand, a level that could triple in 20 years. This increase means greater energy costs, increased greenhouse gas emissions, and a greater burden on the electrical grid. To combat rising electronic energy use, many energy experts have proposed new efficiency requirements that determine how much power consumer electronics may use. There is no legislation in Congress to establish such rules, however states like California and Massachusetts are considering new standards for television efficiency.
I often ask students to do a so-called back-of-the-envelope calculation. Estimate the number of homes in the U.S. (say, 100 million). Estimate the number of remote control appliances in an average home (say, five, including a couple of TVs, a stereo, a garage door opener, etc.). Estimate the number of watts for each appliance as it sits waiting for the user to push the remote (say, 2 watts, less than a night light's amount of power as its circuits stay warm all the time). How much power does the U.S. use to have the convenience of instant-on-appliances? As much power as a small city uses (100 million x 5 x 2, which is 1 billion watts, not counting the power the appliances use when they are on). So an entire city-sized power plant is running to meet that usage. (Of course, this exercise is intended not to get a precise answer, but to develop in the students a sense of scale and an ability to estimate).