Tuesday, October 31, 2006

MythTV energy costs

...between £165-£330 per year!

I'm increasingly disturbed by the energy consumption within my home and some time ago, bought a little plug-in power monitor to see where all of those KWh were going. The monitor plugs in to a wall socket and the kit plugs in to the monitor, either directly or indirectly via a PDU.

It was quite useful in showing me that my cable-box consumed 100% power while on standby and my MythTV server and slave frontend consumed around 150W.

I have a lot of kit that currently runs 24x7. Different parts of it are needed for recording shows, for watching shows, for when people are in the house or for remote access. There's a Venn diagram in there somewhere but here's the list:
  • MythTV Slave/frontend inc. ATA disk, PVR350, USB-serial convertor, homebrew serial-IR sender
  • MythTV backend inc. 2x ATA disk, DVB-T card, USB2 card
  • External USB2-ATA enclosure and disk
  • USB2 media card reader
  • USB2 webcam (currently off)
  • NTL cable-TV box
  • RGB-SVideo convertor
  • 100Mb switch
  • Airport Express
  • Broadband router
  • NTL cable-broadband box
  • Subwoofer (in auto-standby mode)
  • AV amp (in standby)
The rest of my AV kit (DVD player, Plasma screen, VCR) is controlled indirectly by my AV Amp via a special relay-controlled PDU. If the Amp is off or in standby, the PDU cuts power to the AV kit.

A lot has changed since I first looked at the power consumption of my Myth setup. Due to varying size/noise/location requirements, it used to be spread out around the house but now almost everything resides in the same location, in the cupboard under the stairs. This should make consolidation and power control somewhat easier & cheaper.

I now have an Electrisave. It's a device that can monitor the power consumption of individual power-circuits or an entire home by electromagnetic current sensing. Mine is clamped on my house feed and reads a steady 0.25Kw when the house is quiescent, ie. with no heating, cooling, lighting or domestic appliances running. That's 2190 KWh, 2 Tons of CO2 or about £250 per annum.

Not all of this is down to the PVR subsystem. I have a bunch of devices on standby; clock-radios, a stereo and the microwave. There are also a handful of other devices drawing power such as a wireless phone base-station/holder and electric toothbrush charger.

I'm determined to get to the bottom of this 250W; my short-term goal is to halve it and this will definitely need me to completely re-think my current MythTV setup...