cableTVI have become my dad.  I can recall countless times during my youth, that I heard my father say, "Turn off that light, no one has been in that room for half an hour!"  Or, close that door, I'm not air conditioning Overland Park!"  He had many other sayings related to the same subject, which was the conservation of our energy use.  My kids are now the recipients of this banter, and I imagine that the reaction I often receive is similar to those of myself and my siblings.  These days, it is not so simple as turning off a light in an unoccupied room or closing a door.  We have so many gadgets plugged in now that most of us would be hard pressed to put a number to them without walking throughout our homes.  More often than not, I'm now asking that they unplug unused power supplies, or to turn off the game console.

I've read a lot lately about various devices around our homes and the amount of power they use, even when they are not in use or turned off.  There have been many terms coined to describe this usage, such as "energy vampires".  This refers to devices that continue to draw power even when the device is turned off, or the device being charged is no longer connected.  The examples most cited are mobile phone or tablet chargers, or cable set top boxes.  I started wondering just how much energy does go to waste for devices not in use.  Since our televisions in my home all have working "on" switches, but apparently have defective "off" switches, I thought I would start with the humble cable Set Top Box (STB).  For some reason, the TV gets left on and the cable box gets turned off or eventually times out due to inactivity, and goes into "standby mode.  My initial intent was to determine how much one could save by making sure the cable box was turned off when not in use.  I was also curious to see how much power the set top box used while 'powered down'.  

 

What was tested

I'm a Verizon FIOS customer, and have been for a number of years.  My original setup was one HD DVR STB, and one non-HD STB for an older TV.  Since my original install, my original DVR died, and I now have a newer model with greater capacity.  I've also upgraded my TVs to newer HD models and gained one additional TV, for a total of three.  This required the addition of one new HD STB.  Verizon offers multi-room DVR access, so there is no need to have a second or third one for the additional TVs.  What this leaves for me to test is a newer model HD DVR STB, an older HD STB, and one newer HD STB.  Here is the line-up:  

 

 QIP7100 1 HD

This is a basic High Definition Set Top Box, the original older model I started with.  It is a larger form factor, and has a LED clock display on the front, which is always on, even when the set top box is powered off.

QIP7100

 

 QIP7100 2 HD

This is the newest HD Set Top Box Model model availble at the time of this writing.  It is not a DVR model, and just acts as a standard cable box.  It is advertised as a low energy model, It has a relatively small form factor, has only a small white LED on the front to indicate it is powered up.

QIP7100 2

 QIP7232 2

This is the replacement DVR, the newest available at the time of this writing.  While the fom factor is slightly smaller than the model it replaced, it is still a near full sized Set Top Box.  It has a white LED clock display that remains on regardless of the power status of the box.

QIP7232 2

 QIP7200

This is the original HD DVR Set Top Box (HD) that I started with.  I'm including it for comparative purposes only; since I traded it in for a newer model, I no longer have it available for test.  It is similar to the 7100 model in form factor, and has an amber LED clock display that stays on all the time.

QIP7200

 

 

How the testing took place.

For measurement purposes, I used a P3 Kill A Watt model P4400 Electricity Usage Monitor.  I have other test gear that works great for instantaneous readings, but I always find myself going back to the Kill A Watt for one reason; it monitors that actual usage over an extended time period.  It is easy to use, and it gives your various readings as of the moment as well.  The way it works is you just plug it in, then plug in the device you want to measure into the Kill A Watt meter,  Leave the device under test plugged in for about a day, then come back and read the hours and minutes under test, and the kWh used during that time period.

For each STB tested, I ran it for about a day in each mode (both powered up and in standby/off mode).  I then calculated the devices kWh per hour.  Once I had that, I determined how much that cost at my electric companies rates to get an hourly cost for the device.  My electricity provider charges one rate for the first 1000 kWh, and a second, higher rate for usage above 1000 kWh.  For this test, I averaged the two rates.

 

Results.

 For the results, I expected a little more data than this.  The reason there is only one line of data per model is that each of these STB's use the exact same amount of power whether they are powered up or "turned off".  See the chart for the power usage by model, and the annualized cost for my electric company whose blended rate is $0.10187 per kWh.

 

Model

Power Req.

Hrs

Kwh

Usage rate/hour

Cost/hour

Cost/year

QIP7100 1

21W

21.15

0.46

.021647

.0022051

$19.32

QIP7100 2

16W

23.766

0.38

.0159892

.0016288

$14.27

QIP7200

30W

       

$25.40*

QIP7232 2

24W

39.083

0.89

.022772

.0023197

$20.32

*The QIP7200 results were estimated based upon a comparison of the listed power rating to the other STBs tested.

All of the boxes tested have a time-out feature that either blanks the screen or displays a bouncing logo.  This may save some power on some televisions depending upon the technology used to light pixels, but it does not save even the tiniest amount of power used by the STB.  Some televisions have the ability to detect the lack of a video signal, and go into sleep mode, which uses less power. A little research turns up the purpose behind keeping the box completely active and powered up despite the outward appearance.  Keeping the box up and running allows cable companies to perform updates and other maintenance at any time.  Also, if the STP is a DVR model, and it is accepting and acting on program recording instructions, it must stay active to do so.  If it is set up to act as a multi-room DVR, it also must act on other remote instructions.  Despite all this, for some reason I still have to wait for the STB to update itself if I turn it on after it has been unused for a few days.

These result are based only on these particular STB models as configured by my cable provider.  Other providers and equipment are likely to have different results. 

 

Conclusions.

Although I did not get some of the results I thought I might, there are still some take-aways to consider:

  • Getting the latest model of cable box can save you about $5 a year in electricity, but unless you are already heading to the cable company's store, you would be lucky to recover your gas money.  If you have three, like I do, it might be worth it to save the $15 a year.
  • If the television attached to the STB is an old CRT based model, or a plasma based display, configure the time-out feature to blank the screen instead of using the bouncing logo.  These type of TVs actually use less power if the screen is black, or blank.  LCD TVs use the same amount of power regardless of what is displayed.  Also, setting it to blank the dislay may actually trigger the TV's sleep mode.
  • Some STB's have a power plug feature that allows the user to plug the TV directly into the STB, which will cut power to the TV when the STB is powered down, or goes into sleep mode.  This can save some power.
  • It is unlikely that cutting power by unplugging or by a power strip to the STB box would be a tremendous benefit. Even with the highest usage STB, the DVR model, the annual cost is only about $20.  All three of mine together come to about $61.

Lastly, if none of the above points apply to your particular use, don't worry about occasionally leaving your STB on, it certainly doesn't cost you any more.

 

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