SpzToid (869795) writes 224 million U.S. cable TV set-top boxes combined consume as much electricity as produced by four giant nuclear reactors, running around the clock. They have become the biggest single energy user in many homes, apart from air conditioning. Cheryl Williamsen, a Los Alamitos architect, has three of the boxes leased from her cable provider in her home, but she had no idea how much power they consumed until recently, when she saw a rating on the back for as much as 500 watts — about the same as a washing machine. A typical set-top cable box with a digital recorder can consume as much as 35 watts of power, costing about $8 a month for a typical Southern California consumer. And the devices use nearly as much power turned off as they do when they are turned on. The article outlines a voluntary industry agreement that should make a dent in this power consumption (it "calls for a power reduction in the range of 10% to 45% by 2017"), but makes the point that much larger gains are possible: "Energy experts say the boxes could be just as efficient as smartphones, laptop computers or other electronic devices that use a fraction of the power thanks to microprocessors and other technology that conserves electricity. Ideally, they say, these boxes could be put into a deep sleep mode when turned off, cutting consumption to a few watts. At that rate, a box could cost less than $1 a month for power, depending on how much it is used."