If we go back about 4 years then
monitors drew about 70 watts, boat specific pc's drew about 70 watts, laptops drew about 70 watts.
If you had a seperate flat screen
TV then this took about 50 watts.
Then came netbooks which drew about 25-30 watts but lacked some performance, but were a big step forward in energy reduction.
Now in 2014 the energy star TV performance and functionality has taken a step forward so you can save even more watts.
So now it is possible to have a very functional fanless PC that draws around 8 watts and a combined monitor/tv that draws around 8 watts.
fuctionality allows tft, hdmi connections and usb movies.
This means that for around 20 watts, 1.5a at 12v, 0.8a at 24v, you can have a fully functioning PC system.