Cable boxes guzzle energy while nobody's looking

Cable boxes guzzle energy while nobody's looking

Vampires are enjoying a renaissance in popular culture these days, but you may not realize there's an especially thirsty one hiding in your living room. It's the small box that hooks your TV to cable signals and digital video recording (DVR) functions. Officially called set-top boxes, roughly 160 million of these devices are installed across the country, greedily sucking electricity even when they're not being used to watch TV or record a show.

Some of these boxes consume more energy than central air conditioners and large refrigerators. Worse yet, many homes have multiple boxes — perhaps a basic cable box in one room, plus one or more devices with an add-on DVR that eats 40% more power than the basic model. For example, one high-definition (HD) DVR plus an HD cable box consumes an average of 446 kWh annually, significantly more than a 21-ft3 refrigerator.

Set-top box energy consumption made headlines recently when the Natural Resources Defense Council, funded by a grant from the EPA, released a study on the subject. The report finds that in 2010 alone, U.S. set-top boxes consumed 27 billion kWh — equivalent to the yearly output of nine 500-MW, coal-fired power plants — and cost consumers more than $3 billion. However, the report also found numerous opportunities for manufacturers to make these devices more energy efficient.

Today's boxes operate at almost full power even when not in use — consuming $2 billion worth of power while doing nothing. So device improvements, such as adding light sleep and deep-sleep modes, could make a huge dent in energy consumption. The study says the greatest opportunities for energy savings include shifting to whole-house setups with one main box and additional “thin client” boxes, and having boxes automatically shift to very low power levels when idle. Standards that eliminate the need for thin clients altogether - using special TVs instead — could further reduce power draw.

A few statistics show why energy conservation should be at the top of the to-do list for set-top box makers. A typical new HD-DVR box consumes more energy than the average flat-screen television it's connected to. What's more, service providers just recently offered promotions that include free installation of up to four DVR boxes per home, significantly upping overall household (and national) energy consumption. As of 2007, the percentage of boxes with DVR features has mushroomed from 10% to 35%.

These figures might make you think set-top boxes are a prime candidate for Energy Star incentives to promote better energy efficiency. In fact, there have been Energy Star specifications in place for set-top boxes since 2001 and the most recent version kicked in on Jan. 1, 2009. One problem, though, is that cable TV providers pick their set-top box vendors. So consumers don't have the opportunity to pick an Energy Star-labeled set-top box over a less efficient model.

Despite the troubling statistics on set-top energy consumption, Energy Star-qualified set-top boxes are still at least 40% more efficient than conventional models. If all set-top boxes in the U.S. met Energy Star requirements, consumers would save about $1.8 billion annually in energy costs, according to the EPA.

Version 3.0 Energy Star Set-top box (STB) specifications take effect on September 1, 2011, while version 4. 0 begins July 1, 2013. “Savings are expected to be even better in boxes that offer a deep sleep capability. Household energy savings will be better still if the home's boxes are configured using a multi-room arrangement,” notes Katharine Kaplan of the EPA's Energy Star program.

Boxes with better power management designs, including light and deep sleep modes, are already making headway in Europe, where electricity rates are often twice that of the U.S. (And Europe has its own energy efficiency standards for set-top boxes, known as the European Union Code of Conduct for Digital TV Services.) For example, Sky Broadcasting offers a full-featured HD-DVR that uses 23 W when on, 13 W in user-selected light sleep mode, and just 1 W during deep sleep that automatically begins at 11 p.m. unless disabled by the user. Boxes wake periodically to check for new programming requests and provide updates, then go back to sleep.

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The main penalty European TV watchers pay for energy efficient cable is in instant gratification. When users press the power button, the box takes 90 seconds to wake up. This is an issue that American providers say their customers won't want to contend with.

Time Warner Cable is one provider working with the EPA on improving the energy efficiency of its equipment. Justin Venech, a company spokesman, says that all set-top boxes purchased by Time Warner meet or exceed the consumption levels of the tier-one Energy Star specification. However, popular features such as updated programming guides, the ability to quickly power on the box, change the channel, and have instant access to all channels are features that require power consumption even when the box is off.

To cut down on energy use, Venech says the company is continually upgrading its networks, services, and equipment, and implementing new business strategies that result in greater energy efficiency and less overall reliance on the set-top box.

“These efforts include an automatic powering down of DVR boxes after four hours of inactivity, more capable chip sets, more efficient hard drives, and moving more functions out of the box and into the ‘cloud.’ We're also working with consumer electronics companies and embracing new Smart TVs, which will have the intelligence to display our digital cable services and provide a user- friendly interface without a set-top box,” explains Venech.

All figures expressed in kWh per year.

About the NRDC study

In 2010, NRDC analyzed the power usage of 58 pay-TV boxes across the U.S., a few boxes in Europe, and a few video streaming boxes, such as Apple TV. Here's what they found:

  • Energy consumption of set-top boxes is holding steady: Efficiency gains at the component level are being offset by increased energy needs for advanced features, such as DVR. One HD-DVR plus an HD cable box consumes an average of 446 kWh per year, more than a 21-ft3 refrigerator.

  • Internet Protocol TV (IPTV) is gaining share over cable and satellite, enabling the use of more efficient boxes: AT&T's IPTV boxes consume just 18 W when on and 12 W in light sleep mode. Another option is a broadband video streaming service, such as Apple TV, which draws just 3 W when on, and less than 1 W in during sleep mode. Note: Today's streaming devices are often used in addition to set-top boxes.

  • The report calls on manufacturers to design products that meet Energy Star 4.0 requirements as soon as possible, with future boxes entering a low-power state when not in use and waking quickly when needed. Service providers should also deploy new boxes more quickly to users. Consumers can call providers and ask for a more efficient box, if available.

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