When Off Is Not Really Off

July 28, 2008

It is also amazing how many products, such as microwave ovens, regular ovens, televisions, and stereos, still are consuming power when they are assumed to be "turned off." Many of the manufacturers of these products claim that the consumption of these "phantom loads" is negligible, but this isn't true if this consumption is 24 hours a day, 365 days a year.

For example, my microwave oven is plugged into a switched multi-outlet power strip so that I can turn it on only when I want to use it. If it weren't, I calculate that it would consume, over a year's time, twice as much energy when it is "off" than when it is in use.

When was the last time you saw a television set that had an on/off switch (other than battery powered sets)? Most all TVs these days use remote controls to operate them. There has to be a receiver running in the TV at all times looking for a signal from the remote in order to turn "on or off," which is not really "on or off," but really "active or idle."

Also, remember back in the 1960s when it took 30 to 60 seconds after you turned on a TV before you got a picture? Most TVs these days still use picture tubes, which are vacuum tubes, which need to warm up. Why do they turn on so fast today? Because their picture tube heaters are on all the time the TV is plugged into an active wall outlet.

Other examples of "off" not really being off:

The controls for your central heat and air conditioning systems, which usually run on 24 VAC in the US, are on all the time, unless you turn off the breaker or remove the fuses.
The power transformer for your doorbell is drawing about 5 to 10 W (or more correctly, Volt-Amps) all the time, whether the doorbell is pressed or not.
Most battery chargers for cell phones, pagers, battery powered tools, etc., are drawing power whenever they are plugged in, whether they are charging or not.
Many computers and their accessories, such as monitors, printers, scanners, speakers, etc., also are drawing power whenever they are plugged in, whether the computer is in use or not.

If you touch an item and it is warm somewhere, you can bet that it is drawing power. This power is heating up homes, which then, here in Florida, require us to use more air conditioning to cool them.

What can we do about this?

One simple, low cost way for manufacturers to help the cause of energy conservation is to simply include the power consumption of the product, both in use and when idle, on the product packaging. This would help those of us who really do care in making our product choices. Of course, the manufacturers of inefficient products would probably resist this, which in itself helps us make a choice. Another is to include a power switch on those products that have phantom loads so that those of us who don't need the features that this idle current supports can completely turn off the product.

But we don't have to wait for manufacturers to change their ways. We can just unplug items when not in use. Or, for frequently used items, we can plug them into switched multi-outlet power strips and switch these strips off when we aren't using the items. That is what I do with my computer gear, my music electronics, and my microwave oven, as discussed earlier. That is one of many reasons that my electric bills are so low (typically less than $20/month).

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