The Problem: Even when TVs, stereos, and other gadgets are turned off, those little black boxes are still sucking between one and 25 watts of juice. This wasted "standby power" represents as much as 15 percent of your home's total energy consumption. Alan Meier, a senior energy analyst at the International Energy Agency, an intergovernmental policy group, estimates that U.S. households use 45 billion kilowatt-hours in standby electricity every year at a cost of $3.5 billion -- a sum that shows up on our collective electric bill. Or looked at another way: Those sleeping gadgets keep the equivalent of 17 500-megawatt power plants running year-round, just to keep your light-emitting diodes glowing.

The Solution: Meier came up with a couple of simple innovations to reduce standby electricity consumption: Replace the more wasteful adapters with the more efficient switching power supplies, and redesign the software in electronic devices, such as printers, to automatically turn off everything but the most essential components. Combined, these and other changes could reduce the standby power consumption of appliances to less than one watt. Energy Star has developed standby power specs based on Meier's work, and some major manufacturers, including the electronics giants Sony and IBM, plan to similarly reduce standby power consumption in all their products. Federal agencies are now required to buy only these new, improved appliances. Overseas, the Chinese government, after consulting with Meier and conducting its own research, has pledged to reduce the standby power for the 40 million TVs the country manufactures annually.