Good article discussing one of the areas of power use in the home that hasn't been subject to the same progress in savings as other household appliances. No doubt this is partly due to the fact that most of these boxes are supplied by the content provider and thus aren't subject to the same consumer buying pressures.
Atop TV Sets, a Power Drain That Runs Nonstop
Apparently set-top boxes account for 3 billion dollars in power consumption in the US each year and consume more power (annualized) than the average fridge and much more than the TV that shows the pictures.
In the case of our MySky HDi it consumes about 30w on and 23w in low power mode, probably about 220-250 kwhr per year or around 1/2 a fridge and 50 dollars on the annual power bill.
I use an x10 control to switch mine off while not in use. It takes a couple of minutes to boot back up each time which is not an issue for me.
It is to be hoped that suppliers really look to improve on this area in their next product cycles, both running power and standby.