It's the small appliances that can waste the most electricity.
Digital picture frames are small, so it's hard to think of them as energy hogs. But if each U.S. household had one of these frames running around the clock, it would take five power plants to run them all, says the Electric Power Research Institute (EPRI), an electricity-focused research and development nonprofit.
Large home appliances like refrigerators and dryers are typical examples of energy-hungry devices, but energy hogs don't necessarily need to be large in size. Small devices are also collectively sucking a lot of energy from the power grid, and as these devices become commonplace their energy consumption rises exponentially. "It's the subtlety of the effect of large numbers of very small consuming devices," says Tom Reddoch, the executive director of energy utilization at EPRI.
Other small energy hogs include mobile phone chargers and laptop power adapters that are always plugged in to electric outlets. These chargers continue to draw energy even when the devices they charge have been disconnected. And "always-on" appliances like printers or speakers are called "energy vampires" because they also suck up power even when they're turned off or in an idle state.
Worse yet, the number of always-on devices is on the rise. Reddoch estimates that the typical U.S. home 30 years ago had about three always-on devices; today that number has climbed to more than 30.
Slaying energy vampires, however, is worthwhile in the long run. While a refrigerator typically accounts for about 8% of the typical household's total annual energy consumption, Reddoch says, vampire devices account for about 4%.
What's the best way to rein in energy hogs and vampires? The simplest answer is to turn off and unplug devices when they're not in use. If unplugging isn't practical or convenient, use a smart power strip to help stop the flow of electricity to an idle current. For instance, some smart strips allow you to set up a lead device like a computer so that when it is turned off, other supporting devices, like printers and speakers, are also turned off.
We don't often bother to change a device's default settings, but we can save energy here too. For example, you can manually lower the default brightness and intensity settings on a TV.
Knowing how much energy we waste keeping devices on all the time should also motivate us to change our habits. Kyle Tanger, chief executive of green consultancy ClearCarbon, recommends using an electricity monitor like the Kill A Watt, a product that measures the energy efficiency of household appliances, to give you a better sense of their usage cost.
We can also buy energy-efficient products, and this year happens to be a great time to do that. Consumers are eligible for a rebate from the government when they buy an Energy Star appliance. Check out the U.S. Department of Energy website for more information the rebate program.
"There isn't a secret to what's hogging the energy," says Tanger. "If people pay attention to the little lights or fans in equipment, there is a lot in energy-efficiency gain that isn't just low-hanging fruit -- it's on the ground."
Surprising Home-Energy Hogs
Plasma TVs are hot items -- literally. While they are popular, they also consume a lot energy, giving off lots of heat in the process. A typical 27-inch CRT TV uses about 110 to 120 watts and a 42-inch LCD TV uses around 200 watts. Plasmas easily gobble the most: a 42-inch plasma TV uses up to 325 watts.
Digital Picture Frames
Once a high-end item, digital frames are quickly becoming more affordable, with prices as low as $20 to $30. If every home in the U.S. had one of these frames displaying around the clock, though, it would take five power plants alone to power them all, the Electric Power Research Institute estimates.
The high-level graphics processing that creates the visually stunning games on these devices also requires a lot of energy. And a lack of energy-efficiency standards for consoles, like the Xbox 360 and PlayStation 3, doesn't help. The Natural Resources Defense Council estimates that consoles in the U.S. collectively consume around 16 billion kilowatt-hours per year, roughly the same energy usage as the city of San Diego.
Set-top boxes like cable and converter boxes seem like relatively innocent appliances: They typically only draw about 30 watts of energy. But because these boxes are always on, one box over the course of a year can use up to 265 kilowatt-hours, equivalent to the annual energy consumption of a 28-inch CRT television.
Individually chargers for mobile devices like cellphones and PDAs are small energy consumers, only using 7 to 10 watts. But if they are left plugged in to electric outlets even when the charged device is not connected, they continue to draw power. Today most U.S. homes use more than one charger. Add them all up across the country, and they could consume the energy output of several power plants