The newer TVs consume less than half of that so I would assume there would be a difference in heat production.
We have 3 Pan plasmas: 42", 50", and 60" - Smallest to Largest, but also Oldest to Newest.
"Heat output per square inch of panel area" has undoubtedly declined (presumably = Improved) with each newer panel - but (AS A GUESS) the sheer size differential between the 60" and (at least) the 42" offsets the improved efficiency.
One thing to keep in mind is HOW the power consumption is determined. For example:on the two older panels, "Standard Mode" is BRIGHTER than Cinema, whereas with the newer set (a 60ST50) "Standard" is the Least Bright picture mode (given all are at their Default settings).
IF Panasonic measured all three panels at Default Standard Mode Settings, the "Improved Efficiency" of the 60" would likely be overstated for MOST users.
That is, WE run the 60" in Cinema most of the time, moving to Custom for some viewing (particularly for day time / bright room viewing - & notably for Sports broadcasts).
The various "picture settings" posts on the board suggest that MOST users also do NOT routinely use Standard, thus foregoing Energy Efficiency in favor of Improved PQ.