This article was originally published in the July/August 1997 issue of Home Energy Magazine. Some formatting inconsistencies may be evident in older archive content.


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Home Energy Magazine Online July/August 1997


Pulling the Plug on Leaking Electricity

Figure 1. Comparison of operating and standby energy use of various compact audio systems.
Electronics manufacturers have been producing an increasing number of products, such as TVs, VCRs, and compact audio systems, that do not have a true off switch. These devices stay in a standby mode ready to be switched on by a remote control. Although they appear off, they are actually drawing energy (see Leaking Electricity, HE Nov/Dec '93, p. 33, and Off Is a Three-Letter Word, HE July/Aug '96, p. 42).

How much electricity leaks in these new electronics? Recent measurements of several different devices by researchers at the Lawrence Berkeley National Laboratory revealed some surprising results.

The standby power of different appliances and of different brands of the same appliance varies considerably. As Figure 1 shows, the operating power of four different compact audio systems consumes between 8 and 26 watts. The standby power varies from 5 to 14 watts for these systems. If a compact audio system plays for one hour per day (average use), and consumes 25 watts while turned on and 12 watts in the standby mode, its overall electricity use is more than 10 times what it would be if it were truly off.

The measurements also revealed that the size of the appliance does not necessarily correspond to the amount of leaking energy. For example, the new generation of projection TVs with 46- to 60-inch screens are among the less thirsty standby guzzlers. Switched on, they consume between 130 and 190 watts. On standby they use between 1 and 4 watts. This standby performance is better than that of a standard-size screen TV (7 watts).

Other TV features, such as electronic program guides (EPGs) demand higher standby power. When using EPGs, such as Starsight, certain components of a TV--that is, the tuner, amplifiers, filters, demodulator, and the Starsight module--must stay on 24 hours per day in order to receive the needed data.

Standby energy gets used in various ways. About 25% of standby power is due to transformer losses. This is because the transformer is designed for nominal output and is poorly utilized in the partial load range. The other 75% is channeled into components of the electronic device such as the clock, which generally uses 10% of standby power.

These hidden juice guzzlers can add up; they typically consume about half the energy used by a new energy-efficient refrigerator. The best way to avoid this waste of energy (and money) is to identify the losses and to raise consumer awareness so that buyers can make more informed decisions when choosing an appliance.

Because the market for TVs is very competitive, features like energy efficiency may play a bigger role in the future. Consumers have not yet taken an interest in the standby energy performance of appliances, and little information on this feature is currently available. The U.S. Environmental Protection Agency's Energy Star Program on TVs and VCRs will be launched January 1, 1998. The program should begin to change this situation by drawing more attention to an appliance's standby and overall energy performance.

Although you can't plug up leaky appliances, you can unplug them. Read the energy consumption labels and disconnect these appliances when you are going to be away for a long time.

--Wolfgang Huber
Wolfgang Huber is a visiting researcher at Lawrence Berkeley National Laboratory.


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