3DTVs Like Power
Tests of four models, including both plasma and LED-backlit LCD TVs, found 62 and 101 percent greater power draw in plasma sets and 29 percent more in one of the LED sets. In addition, the other LED set used more power in 2D mode than in 3D mode.
There are two reasons for the increased power usage. 3D requires a brighter image because each side of the active shutter glasses is blocked part of the time. In addition, the tint of the glasses causes further light loss, for which the set must compensate with higher brightness.
See c|net. (Pic courtesy of Secretlondon via Wikimedia Commons.)