April 24, 2001
Berkeley Lab Science Beat

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The energy crisis has given rise to a growing set of energy myths. In this article, researcher Evan Mills of Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division reviews the myths and then lay out the facts.

Myth: When my appliance is turned off, it’s off.

Fact: We’ve found that most devices continue to consume power when they’re switched off, sometimes as much power as when they’re on! A surprisingly large number of electrical products -- from air conditioners to VCRs -- cannot be switched completely off without unplugging the device. These products draw power 24 hours a day, often without the knowledge of the consumer. We call this power consumption "standby power."

Myth: Fluorescent lighting is unhealthy.

Fact: Fluorescent lighting has changed dramatically in the last few years. Today’s fluorescents have greatly improved color quality. And the annoying  flicker and hum has been eliminated from fluorescents that use electronic ballasts. Of course, fluorescents are more efficient than standard incandescent lighting. Because they require less electricity, fluorescents generate less power plant pollution, emissions which have many known health effects. Flourescent lights also contain small amounts of mercury, and should be disposed of properly. However, even more mercury releases are avoided thanks to reduced use of the mercury-containing fossil fuels used to generate electricity. If it’s been awhile since you tried fluorescent lights, you might give them another chance.

Myth: Halogen lighting is super-efficient.

Fact: It’s true that halogen lights use less energy than standard incandescent bulbs. However, compact fluorescent lights are nearly three-times as efficient as halogen and don’t have the energy-hogging transformers. Also, halogens require transformers that can use extra energy, even when the light is off.

Myth: Cleaning refrigerator coils improves efficiency.

Fact: While this seems intuitively logical, and very small savings may indeed arise, efforts to actually measure this effect on residential refrigerators have typically come up empty-handed.

Myth: Leaving lights, computers, and other appliances on uses less energy than turning them off and also makes them last longer.

Fact: The small surge of power created when some devices are turned on is vastly smaller than the energy used by running the device when it is not needed. While it used to be the case that cycling appliances and lighting on and off drastically reduced their useful lifetimes, these problems have been largely overcome through better design.

Myth: Energy efficiency products increase the initial cost of houses.

Fact: While efficient products usually cost more, in some cases there is no, or even less initial cost. Most efficient products are also premium products (in terms of features, warranty, etc.), so it's difficult to say what you are paying for the efficiency. In some instances, efficiency can even reduce first cost as in the case where smaller "down-sized" heating and cooling systems can be installed if they’re highly efficient. Smaller units with high efficiency generate as much heating or cooling benefit as large, inefficient ones.

Myth: Insulating the ceiling will just cause more heat to leak out of the windows.

Fact: Adding insulation to one part of a home won’t increase the "pressure" on heat losses through other parts. However, it is certainly true that poorly insulated areas will be the major loser of heat and they often merit attention before improving already well-insulated parts of the home.

Myth: Switching to electric room heaters will reduce your energy bill.

Fact: This is true only under some circumstances. If you have central electric heating, then using room heaters will most likely save you money. But, if you have central gas heating (which is far cheaper per unit of useful heat), you can easily match or even exceed your heating bill by switching to electrical units. Further details online.

Myth: Electric heating is more efficient than fuel-based heating.

Fact: It’s true that all, or almost all, of the electricity that goes into an electric heater is transformed to useful heat in your home. However, making electricity is an inefficient process, with as much as two-thirds of the input energy (coal, natural gas, etc.) being lost in the process. This is why electricity is so much more expensive for the consumer than direct fuels.

Myth: Buying an efficient air conditioner or furnace will automatically reduce my utility bill.

Fact: This is true to some extent, but you won't realize all the possible savings if the equipment is not sized or installed properly. Studies have shown that typical air conditioner and duct systems are improperly installed, wasting one third or more of the energy used by the air conditioner. New and replacement equipment (and ducts) need to be properly designed and installed to realize all the possible savings. The same caveats about proper installation hold true for insulation, windows and many other energy-efficiency upgrades.

Myth: Installing foam gaskets in electrical outlets will significantly reduce air leakage.

Fact: Measurements have shown that less than one percent of a home’s air leakage is due to electrical outlets.

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