No they do not turn off. LNBs take a bit of time to heat up and stabilize when cold. If the HD spun down, when you turned it on to watch TV it could take 15 seconds of more for it to spin up and everything settle it.
Boy you differently don't live in NY.gentleman in this day and age where tech is the only way to go you pay for what you buy. i have five hdtv and four 612 dvrs, 4 laptops and 2 desk tops which are always on. our microwave and toaster oven uses more power than all the others combined. i only pay 225.00 per month to fpl. and i have gas for cooking heating generator and dryer for 30.00 a month. to lower your bill u need to have gas and electric or your goning to pay a lot more. that is my two cents. alswo my air is on 24/7 even in the winter.