Not a big problem
Originally Posted by ScottXe
If there is no power off button, the Chromecast will operate as long as the AC adapter is connected. It wastes the power when you do not use it and is an environmental issue. How come does it have such design flaw? Looking at the spec, it is CEC compatible but not every old TVs are CEC compatible. Google must fix it to save the energy as you know now energy saving is very heated subject.
Tested with a kill-a-watt meter it consumes 730 watts a year idle, that's like $0.27 a year. That's really low for any type of media player or set top box. So it shouldn't be a problem.