Energy Efficiency - Fact or Fiction?
August 14, 2009
New York Times
NEW YORK (AP) -- You're a savvy consumer and you know how to cut corners when it comes to energy. You've given your dishwasher a rest and picked up a soapy sponge again. You even make sure never to fill your gas tank more than half way because you get more miles to the gallon
Or wait, is it the other way around? Is it better to leave the computer on all day or shut it off when not in use? Does my refrigerator use less energy when it's empty or full?
We spoke with people in the know at the Department of Energy, Edison Electric Institute, AAA and General Electric Co. to find out once and for all what is fact and what is fiction when it comes to powering down.
COMPUTERS AND ELECTRONICS
Screen savers save energy
FICTION -- Those hypnotizing screen savers give the illusion that your computer is on some energy-saving standby mode, but in reality, electricity is still pumping to keep your computer and monitor running. In fact, screen savers may even prevent the operation of your computer's power-down feature - which actually will cut down on energy use. Screen savers may even use more energy than a basic blank screen.
Your computer stops using energy when it's in sleep mode
FICTION -- Computers still use energy when in sleep mode. However, the electricity drawn in sleep mode is about 70 percent less that what is used when a computer is awake.
You waste more energy restarting a computer repeatedly than letting it run all day
FICTION -- Even though a small surge of energy is required to start up a computer, this amount is less than the energy consumed when a computer runs for long periods of time. If you plan to leave your computer for 20 minutes, trim some costs by switching off the monitor. For an absence longer than 2 hours, shut it down!
No energy is used after you turn appliances and electronics off
FICTION -- A plasma TV or stereo system when turned off still slowly drains electricity, a phenomenon called ''phantom load.'' Solve this unnecessary waste by unplugging appliances or using a power strip that, when switched off, will cut off power to the device. There are even power strips now that you don't have to switch off. They do it for you and turn back on with the click of a TV remote.
It's more efficient to keep your refrigerator full than half full
FACT -- The larger the mass of cold items in a refrigerator or freezer, the less work is required to maintain the appliance's chilly temperature. You don't need to stuff the case to its limits, but simply keep the space respectfully occupied with food and liquids -- a gallon of water if you have it -- as these items retain the cold.
Hand-washing dishes is more energy efficient than a dishwasher
FICTION -- Dish washing by hand seems like less wasteful option, but it actually consumes more water and energy. People typically leave the hot water running, using up to 14 gallons of water on average. Heating that many gallons of water is far more costly than energy-efficient dishwashers, many of which have a booster heater, a localized heater that raises water temperature for just 5 to 10 minutes. New dishwashers typically use up to 7 gallons of water per cycle. GE Appliances' Paul Riley says to get the most out of an energy-efficient dishwasher, make sure it is fully loaded with food scraped off the plates. No need to waste more water with a pre-rinse. Scraping is sufficient as dish detergent actually needs something to clean, otherwise it will work at the finish on your plates.
Wash clothing with hot water for a truly effective wash.
FICTION -- Heating the water for laundry makes up about 90 percent of the energy used for washing clothes in a conventional top-load washer. Older washing machines heat up to 40 gallons of water, a major drain on energy. Cut out the hot water and you've got yourself some major savings. Using warm and cold water can be just as effective and can slash your energy use in half or more. Other ways to save: wash only full loads and switch to an energy-efficient front-loading washer.
CARS AND FUEL
It's better to fill your gas tank halfway than full because the full tank weighs down the car and is less fuel efficient
FACT -- The lighter your car, the better the fuel economy; which is why a half-full tank of gasoline makes your car run more efficiently. But according to AAA, the degree of savings is negligible. But, if you are a pack rat, you might actually see more savings if you ditched all the junk in the trunk, like your golf clubs, camping equipment, and other random pile ups.
If you live in a warm climate, buy a light-colored car.
FACT -- ''It's one of those esoteric gas saving tips,'' said Robert Sinclair Jr. of AAA. It has the same cooling effect as wearing light colored clothing in hot weather. The lighter colors reflect the heat, whereas dark vehicles absorb heat and require more air conditioning to cool down.
AROUND THE HOUSE
If you live in a warm climate, paint your house a light color
FICTION -- While the light-color theory applies to cars, it does not entirely work for houses. A light-colored roof helps dial back the temperature in a home's attic by reflecting sunlight, but insulation is the key factor when it comes to energy savings. The paint color chosen for the sides of the house don't make much of a difference. To really cool down your digs, focus on proper insulation and planting thicker foliage to block the sun's rays.
Shut the door and vents in unused rooms
FACT -- This works only if you close the doors and vents in multiple rooms. If you only apply this strategy to one room, you won't reap a whole lot of savings.
Leave the heating or cooling system on all day. If you shut it down when you're away, the system needs a surge of energy to reach the desired temperature.
FICTION -- Switching the thermostat off when you go to sleep or leave for the day will boost energy savings. Sure, it will suck up a little more energy as it works to bring the temperature back to your desired level, but less energy is used during the down times.
The longer you sweat out those hot summer days or bundle up in the winter while your thermostat is switched off, the more you can shave away at your energy bill. When the system in action, the Edison Institute recommends holding back a degree or two, as you will realize a 2 percent savings on your bill for every degree you cut back. Of course, this only works if you are doing that on a consistent basis.