A study by environmental activist group Natural Resources Defense Council claims that US set-top boxes use more power than the average refridgerator.
Among the key findings of the NRDC's Energy Facts report (pdf) is that the current generation of set-top boxes operate at 'near full power' even when the user is not watching or recording a television programme. The report cited the extremely wide penetration of such equipment in American households, more than 80 per cent, concluding that 27 billion kilowatt-hours of electricity were collectively consumed by the devices.
The figure is equivalent to the output of nine entire 500MW coal-fired power plants, they claimed. Two thirds of this was used by the devices when they were not 'in use', said the report, which costed consumers collectively a billion dollars a year and resulted in the emission of 5 million metric tons of CO2 every year.
Providing a typical chart of electricity consumption, a recent model HD set-top box was said to consume 171kWh/year while a model with a PVR functionality, Eg. a hard drive, raised the figure to 275kWh. A 'typical' household configuration of one HD set-top box and an additional HD DVR capable unit would be 446kWh combined, more than a 21 cubic feet household fridge at 415kWh.
However the UK's Sky Broadcasting came in for praise with the broadcaster's 'highly featured' HD-DVR drawing 23W in 'On mode' and 13W when the box is in sleep. The environmental activist group was particular impressed with the default 1W 'deep sleep' state that is triggered at 11pm every evening, only waking every half hour to check for events.