A sd stb without a dvr consumes about 18 watts of power which if left on for 24 hours can consume about 105 units in a year. Stb with sd dvr as well as stb with hd only consume about 30 watts of power which if left on do 24 hours can consume about 270 units in year. A hd stb with dvr consumer about 50 watts of power which is about 438 units hd left on for 24 hours all through the year 