Cnet monitored the number of watts used from four different 3D TV models and studied how they changed when toggled between 2D and 3D content.
The two Panasonic plasma models saw a dramatic uptick in power usage, while the Samsung LED model also jumped by more than 20%. However, the Sony LED model actually saved more power when it was put on 3D mode.
Panasonic's TC-P50VT25 50-inch plasma used 160.91 watts in 2D mode and 260.53 watts in 3D mode, an increase of 38.24%.
Panasonic's TC-P65VT25 65-inch plasma used 176.84 watts in 2D mode and 354.71 watts in 3D mode, an increase of 50.15%.
Samsung's UN55C8000 55-inch LED used 118.73 watts in 2D mode and 152.89 watts in 3D mode, an increase of 22.34%.
The abnormal one was Sony's XBR-HX909 LED TV, which used less power than any of the other TVs in any mode, only clocked in at 106.66 watts in 2D mode and 104.65 watts in 3D mode, a decrease of 1.92%.
Cnet could not say for certain what caused the change in power, but guessed that it was because of the extra brightness required to display a 3D image. This was the most noticeable in the Panasonic models, while the Sony one actually seemed to dim a bit when switched to 3D.