It’s nice to be right sometimes

The next issue of Sound and Image should contain my review of the Panasonic 50 inch 3DTV. In that review I wrote:

The very first TV for which I formally measured the power consumption using the international standards was the Panasonic Viera TH-50PZ700A in October 2007. That fifty inch model’s default startup mode was with a horrible ‘Dynamic’ picture setting that sucked up 550 watts. Switched to the rather better ‘Normal’ picture mode, it still used 495 watts. On today’s power usage labels that would have earned it negative 0.5 stars!

Today’s Viera TH-P50VT20A Plasma TV defaults to ‘Normal’ and uses only 181 watts by my measurement. That confirms Panasonic’s rating of four stars. On my figures, the annual power consumption would be 664kWh per year, rather than the label’s 705.

In normal viewing, as far as memory permits, I couldn’t say that it is visually any less bright for the reduced power consumption. So where has the saving been made?

Primarily in heat is my guess. The ‘neo-PDP’ technology is more efficient, so for a given brightness not as much power need be applied. In addition, it allows the cells to go darker with reasonable linearity than the technology of three years ago, so blacks don’t have to be deepened by dark glass over the face of the TV. The TV, therefore, doesn’t have to be overpowered to produce adequate brightness through the dark glass.

As a result, this TV runs mildly warm, whereas the TV from three years ago pumped great quantities of heat into the room.

I was in Myers today and was admiring the non-3D Panasonic VIErA TH-P50V20A. This is sort of a 2D version of the VT20A. However the 3D TV has had its power efficiency compromised, most likely, by the need to make certain plasma timing adjustments for 3D compatibility, so the V20A actually gets an even higher star rating: 5 stars.

I put my hand on the top, and it was noticably warm. I mean noticably literally, not euphemistically. I could feel that it was warm, but the warmth was gentle. Noticable, but not obtrusive.

So I went over to another TV they had there, last year’s 2 star rated Panasonic VIErA TH-P50V10A. Same picture (there was a whole bunch of Panasonic TVs running Toy Story in parallel.). Same apparent brightness. Put my hand on top, and it was positively blasting off the heat. I’m not sure I would have wanted to leave my hand there very long at all.

So I figure my impression and guess, mentioned above, were right.

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1 Response to It’s nice to be right sometimes

  1. Simon Reidy says:

    I’ll have to check out the power ratings for my PZ50800A given it’s the model in-between the examples you gave. Mind you mine is the last series before they move to the new NeoPDP panels so it’s energy consumption is probably very similar to the preceding 700A.

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