Although I’ve set my MythTV box to shutdown when not in use, we still have a constant power drain of 34 watts even when the system is turned off due to various peripherals and parasitic power drains.
- The UPS & Computer, even when turned off, takes 9 watts (Mostly the UPS keeping its battery charged).
- The external USB Hard Drive takes 7 watts.
- The printer takes 6 watts when in standby mode.
- The DVD/Amplifier, even when turned off (in standby mode) takes 5 watts of power.
- The HDTuner (Silicon Dust HDHomerun) takes 4 watts of power even when idle.
- Various other items (PDA charger, External Antenna pre-amp power injector, TV when off) take around 3 watts.
I purchased a “Smart-Strip” LGC5 surge protector. I purchased the LGC5 instead of the APC P7GT because it had more “controlled” outlets and a built in surge suppressor for the antenna (coax) cable, plus it was a few dollars cheaper. It has two “hot” always-on outlets, and one “master” outlet that controls 4 other switched or “slave” outlets. I plugged my computer into the master outlet, and the printer, external USB hard drive, HDHomeRun, and PalmPilot charger into the slave outlets. This saves 17 watts of power when the computer is turned off. (Lowering our idle consumption from 34 watts to 17 watts, or a 50% reduction).
Assuming the computer is idle 20 hours a day (which is a conservative estimate) I am saving 124 kWh of electricity a year, or $12.40 (at 0.10/kWh) a year. The $25 smart-strip will pay for itself in around 2 years.
I decided to not switch the antenna preamplifier or DVD/Receiver via the computer so that we could watch TV using the TV Tuner, or watch DVD’s using the DVD player without turning on the computer. The TV is relatively efficient (when in standby mode) taking less than 1 watt when in standby. Currently, the only reasonable things that I could do to reduce idle power usage further is to purchase a more efficient UPS or replace the DVD player, which takes 5 watts even when in standby mode. (Because both of these items are relatively expensive to replace, doing so only for a few watts of energy gains is not cost effective. But, when I do need to replace them, I will be sure to buy Energy Star compliant models.)