You must have an old-style LCD. The VIZIO VW32L I once considered uses a much more reasonable 104 watts.
http://www.newegg.com/Product/Product.aspx?Item=N82E16889197003
Listed at 180 watts (720p) (I got it cheaper elsewhere)
There might be little fans in there for cooling. You would be surprised. This adds to wattage. A cruder hotter board and LCD lamps but maybe more reliable