HTPC Upgrade

My Ubuntu Linux Mythtv Home Theater PC (HTPC)

Hey folks-

So I finally was able to get my Dad (aka...someone with Linux experience) to help me set up my HTPC for maximum power savings.   So what's a HTPC or Home Theater PC?  Think of a Tivo or Digital Video Reorder (DVR) that your cable company makes you pay for.  Except this is homemade, stores significantly more than just TV recordings, but also my movies, music, and pictures.  Well...it will eventually...in my last upgrade I still have slacked in moving my pictures and music back over to it. 

OK...so after my last upgrade, I was able to reduce my overall power usage from 120W to 95W.  I use the term "overall" because the power usage is not just the PC itself. I have the following additional equipment:
1)  Network switch for multiple ethernet using devices
2)  HDPVR to record TV off the cable box
3)  Crappy Cable Box from Time Warner Cable
4)  Signal Booster because I have to split the Cable TV signal 4x
5)  HDHomerun tuner to record my local QAM TV

I also have a remote frontend unit (think mini-computer) that allows me to stream everything from the main HTPC to the downstairs TV.  That unit is small and only uses 19W.   I had already setup this frontend to 'sleep' when I shut off.

Well...of course, for me, 95W running 24x7 was not acceptable.  So I emarked on the next level of upgrade.  Luckily, this was a software upgade, not hardware.  With significant help from my Dad, we setup the HTPC to shut down between recordings.  So, once a recording is finished and it's been commercial flagged, the system reviews when the next recording is upcoming.  If its a long enough time (20 mintues), it will shut down the PC.  It will not shutdown the PC if (a) someone is logged in (such as when I'm using it) or (b) if the downstairs frontend is running.  So it's not going to shut down right in middle of someone watching a recording. 

It took a lot of tweaks to get everything operating right, but it seems to be running well. I have since grabbed a smart power strip to shut down as many accessories as I can when the PC shuts down.  This is mainly the HDHomeRun and the HDPVR.  I tried to use the signal booster, but I found out that if the Cable Box reboots, then it can't connect/fully reboot until the signal booster is on.  And it takes frickin' 8 minutes to boot!  So if I want to start recording something right away, I can't do it because I have to wait for the box to finish booting. 

So, what has this done for me?  Well, I just plugged in the Kill-a-watt meter and I've gotten some preliminary results.  They are as follows:

HTPC Running with all accessories:  95W
HTPC Off with all accessories:  41W
HTPC Off with some accessories off:  29W

Accessory Power Usage:
Signal Booster:  3W
Network Switch:  3W
Cable Box:  23W

Before I go on a rant about my #$*&# cable box, this is showing a 67% reduction in "always on" power usage.  More than likely this will end up being bigger when we factor in operational time and start talking killowatt-hours.  I just started collecting data so I don't have official results...but let's talk about some theorectical values (not counting the frontend since its the same usage regardless):

Before (Operating 24x7):
95W x 24 hrs/day * 1 kWh/1000W = 2.28 kWh/day

After (Assumes used 4 hrs/day:
95W x 4 hrs/day * 1 kWh/1000W + 29W * 20 hrs/day * 1 kWh/1000W = 0.96 kWh/day. (58% Energy Savings)

What did this cost me?  Well...i did have to buy a new solid state hard drive (SSD) for my frontend so I the system could shutdown instead of 'sleep'.  This also significanly sped up the reboot to something like 10seconds and allowed me to write some code that when the frontend turns on, it 'pings' the HTPC to turn it on.  After it waits for the HTPC to boot (that takes 10seconds), then it connects and starts Mythtv. That cost me $57. 

1.32 kWh/day savings * $0.10/kwh * 365 = $48.18/yr.  So my ROI is 1.18 years.  Yeah, I'll take that. 

Now for that &*#$& cable box.  I can't believe it uses 23W!  And the sad thing is that when you 'turn it off', it doesn't save any energy.  Seriously!!!! I checked it with the kill-a-watt meter!  Not even 1W.  Why is this device sucking down this much energy?!? And to top it off...why the heck does it take 8 minutes to boot?  I TIMED THIS!  In the age of superfast computers that use little energy this is ridiculous!!!  My frontend computer uses less energy (19W) and is equipped with a 30GB SSD, a dual core 1.8 GHZ processor, and boots in 10 seconds.  And it probably decodes HD TV faster.  It certainly makes you wonder what the heck is going on with these companies.  I know my TWC service blows and I'm just waiting for the day that there is sufficient competition in NC so they will come out of the dark ages.  My only real alternative is AT&T and their "digital" internet service is nearly half the speed of TWCs.

OK...*pant pant*...calm down boy....off the soap box.

The long story short...this was a fairly painless upgrade that'll knock off some kWh's.  With my new fridge knocking off about 0.5 kWh/day, I'm reduced my baseload usage by ~1.8 kWh/day.  My 'always on' energy usage is down to about 165W (3.96 kWh/day).  There's a couple things I can do to get this down a little futher, but not much.   At least 85W of this power is the upstairs and downstair geothermal systems on standby (~30W each) and then the frickin' cable box (23W).  Then there's things like the alarm clocks, the internet cable modem, and the router.  Yeah...these are staying on.  However, it would only take 500W of solar capacity to completely negate this energy usage.  We'll see when that happens....

Energy/Cost Savings...What to do next?

Ok...I Friday and yesterday I spent countless hours trying to get my HTPC to shutdown and wakeup automatically.  When I manually told it to turn on in 5 minutes and shut it down manually, it worked fine, turning on automatically.  When I let it automatically turn off, it did just fine, but then it wouldn't turn back on.  It appears that I just can't get the system to pass the correct date/time in there.  Not sure why...Long story short...I'm fed up with it.  I'm no linux computer expert and I spent most of my time on Google trying to figure out commands.  I know enough to get by, but that's it.

So, I thought the next most logical step was to finally start looking at an upgrade to reduce power usage since this is on 24/7.  Well...a question arose...are there better investments?  Let's take a look...

I measured all my HTPC components with a Killawatt meter and the total usage is 120W when idle.  The computer itself uses 92W.  Reading online, a nice Intel Core i3 system (with all the accessories) uses around 40W when idle.  So that would save me 52W.  On a daily basis thats 1.2kWh which would save me $0.106/day = $3.23/mo = $38.72/yr.  Generally I would invest about $300 into this which gives me a simple return on investment (ROI) of 7.75 years.  Not all that great, right?

Well...looking at my TED, it's pretty obvious the one thing that is using the most power in my home is the hot water heater (see large single spikes).  The graph above shows last weeks worth of hourly energy usage.  The block on the first day (Sunday) is from doing laundry so that's a mix of hot water and dryer usage.  Overall, It's that time of the year when I don't need heating or cooling, so my geothermal is turned off (House stays between 67 and 75...comfy!).  With the system off, my desuperheater isn't heating my hot water.  So...does it make sense to upgrade my hot water heater?

Well, one of those GE hybrid hot water systems costs about $1400 from Lowe's (I'm not including the tax credit because I can't buy it this year).  If my current hot water heater (4.8kW) is on, say for 2 hrs/day (only 1 hr shown above, but let's factor in winter), then that I'd use 9.6kWh/d which is $0.82/day = $24.8/mo = $298/yr.  A hybrid hot water heater (according to the website) would save me 62%.  So, without factoring in the desuperheater, my ROI is 7.6 years.  With the desuperheater reducing hot water by 40% (a conservative value) then the ROI rises to 12.64 years.  Overall, I'd say this fix isn't worth it unless my hot water heater decides to break.

Out of curiosity, how about solar hot water?  Well...first, I'm not sure if my desuperheater and solar hot water can work together...but let's assume they can.  A solar hot water system (which is not a do-it-yourself job for me given my roof is so steep) would probably cost about $5000 installed.  This is just a guess looking online for similar systems.  What's the ROI?  16.8 years...so yeah, that's out of the question.

Out of these 3, upgrading the computer has the best ROI, albeit the overall savings are small.

However, I think my best bet is going to be contacting my geothermal MFR to see if there's a way for my desuperheater system to heat my hot water.  All the parts are there...there just needs to be some way for the hot water tank to contact the geothermal system to turn on.  And in hot water only mode, then the geothermal system would not turn on the fan.

Always on Electrical Usage

Hmmm...I think its time to tackle the always on Electrical usage. Above is a screenshot from my Google Powermeter.  Notice that my average "always on" power usage is roughly a third of my total power usage.  On some days, that power usage is over a half of my daily power usage!

Really, if you look at my power usage in my previous blog (Phantom Power Usage), by far most of my always on power usage is from my HTPC.  Looking at my schedules, my HTPC really only needs to run for at most 4-5 hrs/day.  So, why is it running 24 hrs/day?

So this weekend, I'm going to look into this.  I've played with this concept before...which works setting it manually, now I just need to get it to work automatically.

I'll keep you posted.