I found this old(?) but interesting comparison of TVs, and TV technology power usage comparison of TVs, and TV technology power usage.

Most interesting was the average power consumptions;
Microdisplay rear projector TV: 0.14 watt per square inch,
LCD: 0.29 watt per square inch,
Plasma: 0.34 watt per square inch,
CRT: 0.34 watt per square inch.

I'll have to keep that in mind , and pay particular attention to the power consumption, when I'm next looking at purchasing a TV, but to be honest I'll only be looking at LCD vs. Plasma.