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How the UFO Power Center saves 50% of energy in my home entertainment system

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It is well known that home electronics appliances also use energy when they are not in use because of “standby” power. When we turn them off, they are actually still operating even if not performing their main function and are in standby. In standby mode an appliance reduces its power consumption and it’s ready to be turned “on” to perform its main function. Modern electronics have mitigated this problem, but a new one has emerged, particularly with set-top boxes and media centers that are never completely off and are always performing some function. This kind of “active” standby power is even more wasteful than that of older appliances and “wall warts”.

As I show in this post using a real life example, the UFO Power Center provides an elegant and effective solution to mitigate the passive and active standby power problem. I have cut energy usage in my home entertainment system by more than 50%, without changing any viewing habits or having to perform daily on/off operations manually. Other devices, such as “green” power strips or timers alone, can only partially address the active standby power, and in any case are not easy to understand or to override, and it is not possible to measure their effectiveness. The automation element provided by the UFO Power Center, together with the ability to know with certainty the effect that automation has on energy consumption, are the key elements that make the UFO really stand out.

Obtaining a baseline

My home entertainment system is composed of the typical audiovisual components of a technophile home. Those include a plasma TV, an AV Receiver/Mixer, a TiVo, the Sling and Roku boxes. I mainly use it for watching TV, movies and streaming audio and video, typically three to five hours a day.

To have a baseline to compare against, I used the UFO itself to measure consumption over a week without enabling any saving measures. The Sling and Roku boxes have been combined together with a dual plug. The setting is perfectly safe as the total power used by all appliances is well below the 1650 Watts limit of the UFO.

The baseline was obtained over a week of normal watching pattern, including an evening out, without any automation settings in the UFO. After one week, the average daily consumption was of 4.18 kWhr or $0.75 (at $0.18 per kWhr).

Baseline typical daily energy consumption

Baseline typical daily energy cost

Baseline weekly energy cost

The realization that the home entertainment appliances use in excess of 120 kWhr or more than $20 a month is astonishing. Particularly because these are all modern appliances, made in the last year or two. The issue is that the TiVo, Roku and Sling boxes are all using active standby power.

The TiVo spins its hard disk continuously and its CPU crunches a lot of cycles, even when there is no recording or viewing. The Sling does not even have a standby mode, and the Roku is using basically the same amount of power whether it is on or off.

Another big offender is the AV Receiver/Mixer, a necessary piece of equipment in my setup where there are several independent sources of audio and video and one display and one set of speakers.

Using Automation

The measures taken to drastically cut energy consumption involve the simple observation that there is no reason to keep the appliances turned on when there is nobody at home. This is a function that the UFO can perform very easily, by setting a Schedule for every socket that needs to be on only during determined hours of the day. However, since there is a TiVo, the schedule has been set around the evening times of prime television rather than strict home occupancy.

The first thing was then to set a Schedule for the TiVo, the Roku and the Sling sockets to be powered on only from 6pm to 11pm. The only time this does not really work for me is when there is a motorsports or soccer event from Europe I would like to record, early in the morning Pacific Time on a Sunday. In these cases, I would setup a One-time Timer to turn on the TiVo at the time of the event I want the TiVo to record, before going to bed on Saturday evening.

The second saving measure is about reducing the time the AV Receiver/Mixer and the TV stay powered on. Unlike the TiVo, there is no reason to turn on either one unless somebody is watching. Looking at the consumption when all the appliances are in standby, it was easy to see that the TV is really using no power in standby and the AV Mixer uses constantly at least 60 Watts. This makes the two perfect to use in sockets with Roles. I set the socket TV as Master with a low threshold of 2 Watts, and the AV Mixer as Slave.

Power used in standby

Calculating the savings

After adding the simple automation settings described above, I used the home entertainment system for another week and then checked the weekly consumption again. The average daily energy consumption is now of 2.1 kWhr a day or $0.37 (at $0.18 per kWhr) which is 50% of the energy used without a UFO.

New typical day energy cost

The consumption during non watching hours is now reduced to the amount used by the Tivo, the Roku and Sling boxes while turned on during prime time. For the remaining of the day the consumption is zero.

New weekly energy cost

The UFO’s socket Schedules and Roles are really addressing different needs and are not overlapping functions. A Master/Slave Role setting alone, as used by some simplistic “green” power strips, does not work with set-top boxes and DVR appliances as they really need to be on at times no other appliance is on. On the other hand, using the Schedule alone in a case like my AV Mixer, would still waste a considerable amount of standby power. Finally, the One-time Timer allows to deal with overriding the daily settings to work around default schedules.

To be accurate, in the calculation I need to consider the additional 2 Watts of power (max) used by the UFO, that corresponds to 1.5 kWhr or $0.27 a month. This is much less of the amount of power used by a night lamp.

In conclusion, it is really the reach mix of automation features provided by the UFO that allows for the significant reduction of consumption described, without affecting the viewing and listening experience or performing any manual switching.


Written by Marco G.

June 16, 2011 at 4:26 pm

Posted in Uncategorized

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