power consumption on plasma & LCD tvs

[Marc]

A report being prepared for the Australian government could lead the the banning of the sale of many plasma and LCD tvs in this country on the grounds of their high power consumption.

Now keeping the politics out of, does the technology actually use that much power (esp. compared to a CRT) or is the becasue we're people buying the huge models that take up half you wall which do use more power compared to on half the size?

 

[Arrqh]

According to some random numbers I looked up, the average LCD TV consumes about 30% more power then a CRT. And the average plasma is over 100% more.

Put if you look at their chart, the 34" CRT uses about the same amount of power that some of the 42" LCDs use. The numbers suggest that LCD's are in fact somewhat more power conservative, but the larger screen sizes they're available in offset that. As I understand the technology correctly, the largest power consumption comes from the backlight.

It'll be great in a few years once we start getting OLED displays that don't require the backlight that Plasma's and LCDs do. Banning them because of their high power consumption seems going a bit too far though, especially considering the other environmental drawbacks CRT's have (especially when you're talking about proper disposal).

 

[Marc]

Arrghman said:

Put if you look at their chart, the 34" CRT uses about the same amount of power that some of the 42" LCDs use. The numbers suggest that LCD's are in fact somewhat more power conservative, but the larger screen sizes they're available in offset that. As I understand the technology correctly, the largest power consumption comes from the backlight.

In the middle they have the figures for the power consumption on a watt per square inch basis and the plasma comes in a the same as the CRT (both .32 watts per square inch) and the LCDs are a tad lower.

Something tells me as the story gets covered that the difference in power consumption is based on the large size might not get mentioned.

But yes you're correct - the backlight is the major source of power consumption in a LCD display - which is why power saving on a laptop always includes turning down the backlight.

 

[farmkid]

Some LCD displays are starting to use LEDs as the backlight, though I think so far it only applies to laptops and computer monitors. Once LED backlights are used in LCd TVs, we can probably expect to see a dramatic drop in the power usage of LCD TVs.

I am surprised at the numbers reported here. A couple of years ago when I replaced my 17" CRT monitor with a 19" LCD, I looked up the power usage of my monitor and some of the LCDs I was considering. My Sony Trinitron used something like 175 watts and the LCDs I looked at were all around 40 watts. That's a much greater difference than the differences we are seeing in these TVs.

 

[JustAFriend]

The thing that worries me the most about plasma TVs is the massive amount of heat they put out.

Put your hand along the top of one sometime.

On many of the larger ones if you're going to mount them directly to the wall, you are required to put a metal heat shield up on the surface of the wall.

So its not just the power required to run one, but the extra air conditioning too!

 

[Marc]

JustAFriend said:
The thing that worries me the most about plasma TVs is the massive amount of heat they put out.

Put your hand along the top of one sometime.

On many of the larger ones if you're going to mount them directly to the wall, you are required to put a metal heat shield up on the surface of the wall.

So its not just the power required to run one, but the extra air conditioning too!

Oh great. The electricity compnay in South Australia is complaining about a particular new development north of Adelaide because of it's power consumption with the large poorly designed houses requiring industrial strength a/c units. So it's not just the design of the houses - it's their plasma tv's too...

 

[Sledder]

JustAFriend said:
The thing that worries me the most about plasma TVs is the massive amount of heat they put out.

Put your hand along the top of one sometime.

On many of the larger ones if you're going to mount them directly to the wall, you are required to put a metal heat shield up on the surface of the wall.

I've really got to wonder about that last part, got any links that show this is actually the case?

 

[JustAFriend]

Will have to look for links...

My wife's company is building ultra-high-end condos and equiping them with giant plasmas. They are having to put heat shields on the wall per the manufacturers instructions... I'll try to get more info out of her.

 

[Borjis]

Plasma TV's don't have back lighting. They are individual pixels and look very much like a crt pixel if you look up close.

I own a Panasonic plasma, its rated at 387 watts.