Lean Computing: Lowering power consumption without sacrificing utility

[2twisty]

I'm starting this thread here since I think that many Pi users will be of similar mind, and many of us use XBIAN for a media center.

I'm starting this as a place to report things that I do/explore as I try to make my media center functional but use as little power as possible.

Some background:

My wife and I plan to go off-grid within the next 5 years. We want to preserve as much ouf our technological lifestyle as possible. One place that we will have to make major changes is in power use. The Pi is one step toward that.

I've run (and still have) some very serious hardware at my disposal. I have an Asus KGPE-D16 Dual Opteron board with 2 Opteron 6128 8-core CPUs (2GHz) and 24GB of RAM and a RAID5 array. At one time, I had my array up to 20TB.

I had a separate 6-core AMD that ran my Windows Media Center.

Then, my priorities changed. Then I got the Pi. I replaced my 46" TV that pulled 340W with a 39" that pulls 130W. That's still a lot of power when you're talking about an off-grid situation.

I've been fighting with my TV to find a way to make it go into standby using CEC codes, but apparently the HDMI Spec (My TV is 1.4) doesn't yet REQUIRE support for the standby command, and the manufacturer (Insignia, house brand of Best Buy stores) flatly REFUSED to give me any info about the vendor-specific codes that can be used to control the set. They claim it's "proprietary."

Asshats.

Anyway, I've got a better idea anyway: I'm going to create (or buy, haven't decided yet) a relay board controlled by GPIO to cut the power to the TV. This will use even LESS power than running on Standby. My initial testing (by unplugging the TV while the Pi is running) has been encouraging.

If there is a video playing I get an "unsupported mode" error. However, if it's just sitting there at the menu, it seems to come back ok. So, in a "screen saver" situation, it likely would work out.

I will keep this thread updated with the results of any testing and modifications. I'll have to write a special screen saver add-in for XBMC for the Pi to control the GPIO port, but I'm hoping that won't be too difficult.

If you guys are doing anything special to reduce power consumption, please add it to this thread. If any of you are already using a relay board to switch 110V AC, please provide links to purchase or designs. No need to reinvent the wheel.