Power Consumption for LCD vs. Plasma: Has it Changed Much Recently?

[hoodlum]

The easiest way to save energy is to buy a smaller TV and move the furniture closer to it. At one time 20" was the standard. If anyone is so concerned about the environment then they shouldn't even be looking at a 42"+ TV.

[Deckster]

There was a whole thread a few days ago about power consumption of electronic devices and the only time to be concerned with the current draw is during the summer. In the winter 100% of the power is contributing to the overall heating of your house at 100% efficiency.

If you're THAT concerned with the environment then you wouldn't use A/C so you wouldn't be paying to remove that extra heat anyways.

[Alan Toronto]

In the winter 100% of the power is contributing to the overall heating of your house at 100% efficiency.

This is not true. While it is true that electricity is converted to heat at 100% efficiency, the creation of that electricity is at nowhere near 100% efficiency. Since a large chuni of American and Canadian electricity is produced from coal, it is very inefficient and unclean. It is important to conserve electricity at all times of the year, not just in summer.

[rsambuca]

And we can all give up everything and go live in caves. I think we are getting a little off-topic here!

[SIYW]

We got this plasma unit (TH-C46FD18) in December 2008. It is our second HDTV; the other one is a 32-in Sharp LCD purchased in late 2006. With HD signal (paid service), this TV is simply amazing. Its picture quality is far superior than that of the LCD set, especially when handling dark/shady images. I will concentrate my remaining comments on energy consumption, which has rarely been addressed.

With the power rating of 628W, we had a long pause before buying it. The worry turned out to be largely unwarranted. Unlike LCD TV, which consumes energy at a constant level (the 32-in LCD run at 134W regardless), power consumption of plasma TV is dependent on (1) the type of program one is watching and (2) how bright the screen is set. The actual power consumption is usually way below the rated value unless one is watching nothing but a bright white screen. The power consumption of this TV is affected most by the settings of “picture mode” (standard-cinema-game-vivid, etc) and “picture” adjustment (range 0-100, actually controls brightness). Both are accessible by pressing the menu button (on remote control) followed by selecting the “picture” icon (on screen). Other settings, such as brightness and color temperature, will also affect power consumption but the difference is rather small. By feeding steady Wii Sport startup page (mostly white background), we measured the power consumption in different picture modes and adjustments using the “Kill a Watt” from P3 International (brightness and color temperature were set at +50 and normal, respectively, throughout):

(Table 1)
------------------Standard Mode (W) ------- Cinema Mode (W)
Picture Adj.
+30------------------not done------------------------374
+40------------------not done------------------------440
+50---------------------353---------------------------508
+60---------------------401---------------------------508
+70---------------------468---------------------------509
+80---------------------501---------------------------508
+90---------------------501---------------------------509

After numerous trials, we settled on the “standard mode” with “+60” picture adjustment for routine use. These settings provide enjoyable watching experience during the daytime in a room with partially open window blind (no direct sunlight). We then took several real world power consumption measurements.

(Table 2)
Program Watched ------Duration (Hour)------Total (KWH)------KW
Syriana--------------------------2.16--------------------0.44-----------0.20
Shawshank Redemption -------2.40--------------------0.46-----------0.19
Golden Compass----------------1.90--------------------0.35-----------0.18
CNN------------------------------1.00 -------------------0.22-----------0.22
Science Channel-----------------1.00-------------------0.26-----------0.26
NBA------------------------------1.40--------------------0.35-----------0.25
Nat. Geography-----------------1.55--------------------0.39-----------0.25
Wii Bowling----------------------1.00--------------------0.31-----------0.31

With the stated settings, this TV uses power ranging from 190W to 310W under several different testing conditions. None of them comes close to the rated value. Our measurements also show that, except for playing video games, this plasma TV regularly consumes less energy than the 32-in LCD TV on the basis of per unit screen area (The screen area of 46-in TV is 2.06x as large as that of 32-in TV; therefore, the 32-in LCD TV is projected to consume 0.27 KW with the equivalent of 46-in screen). Big screen TV is an energy hog, but at least the impact can be managed somewhat with plasma TV. This is a long post, thank you for your patience.

[Alan Toronto]

Gee, that is a lot of electricity consumed.

As for LCD, perhaps your unit is less sophisticated than current models. My Samsung LCD's power consumption does indeed vary depending upon settings and program content displayed.

[57]

I believe that LCD power consumption varies with the backlight setting, but doesn't vary (significantly) with the programming shown, like it does on Plasma (& CRT) - for example, the brighter the picture/programme, the higher the power consumption.

[Alan Toronto]

My watt meter shows a decrease in power consumption when, for example, programming switches from HD to SD with black bars.

[57]

It's possible that you have one of the "auto" settings on, which varies the backlight.

Of course, some of the new LED LCDs have local dimming, so that would also account for variable power consumption on those (LED) LCDs.

[David Susilo]

The problem with "sit closer to the tv" argument, for a 20" 4:3 TV and to get an image impact equivalent to what I'm currently using, I have to sit about 12" away from the TV when I'm watcjing a 21:9 movies

[cfraser]

Interestingly, I was reading about power consumption of TV types recently. Unfortunately I tossed the mag already. California, as usual, is planning to implement new *requirements* (not suggestions) for energy efficiency for all TVs sold in the state. They can really afford something like this right now, but anyway... They typically set the North American standards for crap like this due to their large market etc. Naturally manufacturers are fighting it, like they do for all "standards" that they don't invent themselves.

Their findings are: CRT-based are most efficient by far, then plasmas, then LCDs (other types weren't mentioned much). On average, etc. etc. LCDs and plasmas were not even that close, nor were CRTs and plasmas. Surprised? Well here's how they determined efficiency, and in some ways it's quite a fair way: they based efficiency on power consumed by square inch of viewing area. And that's how they plan to implement the law, which if/when implemented will no doubt affect us to some extent.

I sure was surprised, it was exactly the opposite order that (internet) legend would have it.

[dogpatchkid]

Its making a comeback, and powerconsumption is better than other technologies. The Mitsubishi Diamond View (54" & 70")laser DLP is advertised as 30% less than LED, with a picture nothing short of OELD can match.

At this point in time anyone buying a plasma is making a statement about conspicious consumption. The sacrifice of LCD, is it realy that bad? The cumulative effect of millions of Plasma is significant. Especially because Plasma buyers tend to start at 50".

I admit with my 37' LCD its hard to get the family of 4 on axis.

[videobruce]

1. Mits isn't sold in Canada,
2. The price is ridiculus ($7k US),
3. It's LaserVue. DiamondView are their other lines,
4. There is only one model and it's 65".

[scampbell]

California, as usual, is planning to implement new *requirements* (not suggestions) for energy efficiency for all TVs sold in the state.

I expect that will be very good for TV retailers in Nevada.

[cfraser]

Some people have a very false assumption about current plasma displays' power consumption, in general (one guy says he can use his as a heater...). I really don't know which ones they're talking about, but certainly not the ones *I* looked at, nor the ones CA used in their measurements. Nor the one I have (which runs "cold" i.e. you can't feel it above room temp anywhere on its surface front or back). It's true they are not efficient when small, but then 50" wasn't "large" even 10 years ago. And guess what: the cheap ones do suck more power. But we shouldn't compare the worst of one tech with the best of another.

Do not compare by the manufacturers' max power consumption spec. Especially for plasmas, it's not continuous and varies as the pic, unlike for LCD etc. which continually draws roughly the same power. From what I've seen, most people watch plasmas in a torch mode, and that's why they bought them. Power consumpton goes up noticeably then.

Measure the ACTUAL total power consumption on similar-sized LCD/plasma screens of good/comparable quality, while watching the same program material, and you'll probably get the same results as the CA efficiency researchers did.

Anyway, since when did "efficiency" have anything to do with luxury goods, "luxury" in the sense they're not necessities or needed to earn a living etc. for the vast majority? A 60" display of any tech isn't even close to "conspicuous consumption" these days, hardly the Hummer of displays. I'd say 110" plasma is though, mainly because they're $80k or something.

Edit: totally OT, but get one of those little power measuring meters for ~$18 from CT on sale. Watch how much your plasma power consumption changes depending on what's displayed...if such things amuse you.