Home Page | About Me | Home Entertainment | Home Entertainment Blog | Politics | Australian Libertarian Society Blog | Disclosures

Know It All: TV Power Consumption -- Standby Standoff

Published in Geare magazine, Issue #47, 2008

A couple of months ago I received a concerned communication from a friend about whether she should follow advice from environmentalists. Specifically, should she clamber under her entertainment unit a couple of times every day to switch on and off the power point into which her TV was plugged, so as to avoid a wastage of energy in the TV's standby condition. And, of course, the carbon dioxide that the production of this 'wasted' energy would pump into the atmosphere.

My gut feeling was that such a thing was pointless, but I thought I'd better run the figures to be sure. In fact, is it worth your while in doing this kind of thing at all?

Her TV was a new LCD model and was specified to use half a watt of power during standby. Let us use one watt, though, so that you can easily apply these figures to any devices you are using. I shall avoid all the boring calculations here -- these would be guaranteed to make this page unreadable -- but it doesn't require a degree in rocket science to replicate them for yourself.

So, let's assume you've got a TV plugged into the wall, it's on standby, and it spends a whole year like that. That TV will consume around 8.8 kilowatt hours of electricity. To put that in context, that's about the same as running a small bar radiator for eight or nine hours.

Where I am in Australia, that would cost me a little over a dollar a year, and on the latest Australian greenhouse gas emissions data I have been able to locate (1.068kg per kWh), it causes about 9.4 kilograms of carbon dioxide to be emitted.

So, let me ask you, is it worth the trouble to switch off your TV at the power point whenever you've finished watching? Let's say that you watch your TV once daily. That means, over the course of a year, you will have to go over to the power point and switch it on, and switch it off again later, 365 times. If the whole on/off process takes you one minute per time, then you will be spending about six hours per year doing it. That works out to savings of about 17 cents per hour of your time.

So, is it worth the trouble?

Let's put this another way. Do you drink tea or coffee? Use an electric jug or stove-top kettle to boil your water? Every time you boil one cup of water more than you actually need for your next cup of tea (assuming the water starts at room temperature), you are wasting as much energy -- and generating as much green house gas -- as leaving a TV on standby for a whole 24 hours. If you're planning to switch off your TV at the power point, then perhaps you'd better think about putting a measuring jug next to your kettle.

I've just measured the standby power usage of a couple of current model major brand TVs, and it turns out that they use the same power as my Nokia mobile phone charger ... when the phone isn't plugged in. That's just the residual power that leaks through its circuits. Sounds to me like it would easier to switch those off when not in use (since you only plug in your phone every few days).

But if you really want to save power and greenhouse gas emissions from your TV, there is a far easier one-off strategy that you can employ. Switch it on and bring up the 'Picture' menu. What do you see there, right on the top line? For most people, this setting will not have been changed since the TV was taken out of the box, and it will say 'Dynamic' or 'Vivid' or some such.

That is the default setting for most TVs because it produces the brightest picture, all the better to compete in the showroom with all the other TVs, all of them producing their own brightest pictures.

Unfortunately, this also tends to be the least accurate picture. Ideally you should calibrate your TV using the THX Optimizer section of some DVDs. But short of that, change from 'Dynamic' to 'Standard' or 'Normal'. If you're watching at night with the lights down, change it to 'Cinema'.

Initially this may seem to produce a dull picture, but over time it is far more satisfying because it is far more realistic.

And it can significantly reduce power consumption.

A big brand fifty inch plasma I've just tested with a standard DVD test clip uses 550 watts in 'Dynamic' mode, 495 watts in 'Normal', and just 328 watts in 'Cinema'. With this TV, if you switch from 'Dynamic' to 'Normal' and watch TV two hours every day, in one year you will save more power than a decade of assiduous power point switching.

If you're really enthusiastic, you can also change your viewing habits. I measured the power consumption of the TV while showing Alex Proyas' appropriately named Dark City, and it averaged 286 watts. For the very bright Vincenzo Natali movie Nothing, which has large sections set on an entirely white background, it averaged 520 watts. Just remember, when you're watching the next season of '24', your viewing is emitting a lot more carbon dioxide during the daylight episodes.

LCD TVs don't vary as much as plasmas, some hardly at all. But an increasing number have a setting for the intensity of the backlight, so you can reduce their operational power consumption. The 'Standard' and 'Cinema' picture settings usually reduce the backlight brightness somewhat, and so reduce power consumption.

The world, it seems, is embarking on a period where a great deal of attention will be paid to the energy consumption of all manner of appliances. No doubt government regulations will be gradually brought to bear on which appliances we should -- or indeed, can -- buy. We will continue to be hectored by those who think that switching off a TV at the power point will save the world.

What we won't see for the most part are the actual figures that will allow the numerically literate to make their own informed decisions.

© 2002-2009, Stephen Dawson