Ultra-low-power Web server

[zeusmorg]

 I looked into that,, unfortunately sheevaplug will not install XP.. and with my voip setup(magicjack) XP is required.

[Bruce S]

Ahh; I understand now. The bummer part of the Dell's, is that they don't use standard PS otherwise you could grab a lower rated PS and use it instead.

Bruce S

 

[DamonHD]

Ah ha! Next step towards world domination!

I now have my little SheevaPlug Linux box running from my off-grid solar PV system, and it's drawing a whole 3W. I don't think that it'll draw more than 6W maxed out the way I intend to have it set up. At 5W it could run off my small solar battery (12V, 40Ah) for a couple of days without a ray of sunshine to 50% DoD...

(Note that just about 1W is taken up just running its Ethernet connection.  The ADSL/modem/WiFi takes ~8W from the mains.)

Rgds

Damon

[DamonHD]

It's actually now running the beefiest application that it has to, my Java-based Gallery, that also runs on a 24-CPU box in co-lo and a couple of other servers round the world.

It's still a tad slow though acceptable for my purposes, and various tuning and other services need to go in, but it lives!  And entirely solar powered off-grid, with my meter saying 3.1W.  B^>

Rgds

Damon

PS. Can't remember if I posted my set-up page, apologies if I did: http://www.earth.org.uk/note-on-SheevaPlug-setup.html

[DamonHD]

I've beefed up the SD card to 32GB and I have ordered a 128GB USB flash drive for bulk storage.  Within a week or so I hope to power down my current Linux laptop/server and be using the SheevaPlug instead entirely off-grid.

(The ADSL modem has to remain on-line for the moment, but I'm working on that.)

So basically I need to move my mail and SVN and remaining Web services (and data) across and I should be done.

The biggest problem I have is the DC power from my 5V regulator which seems to be dodgy!

Rgds

Damon

PS. Separately my MPPT solar regulator should help ensure that there is enough solar power in winter...

PPS. This 'sabbatical' thing seems to involve rather less income and rather more spending than might have been hoped!

[DamonHD]

Hurrah!  Got there in the end!  A 3-month project roughly...

I have just moved the last of my services, mail, to my SheevaPlug.

So everything is now off the previous laptop/server and it is powered down.

Services include Web (static and Java-based), DNS, mail, NTP.

(I'm sure that there'll be the odd glitch and I may well use that laptop for other things...)

The battery got as slow as 'yellow' (part-full) status on my solar controller, so I spent a lot of today fixing various software issues to reduce consumption.

Rgds

Damon

[DamonHD]

Hi,

Did you see the fit-PC?  About 6W consumption and runs XP...

http://www.fit-pc.com/fit-pc1/

Rgds

Damon

[DamonHD]

I'd been down to 'red' for 3 days (hovering at 11.5V) after mid-December levels of (lack of) light, which has probably not done my 2-year-old gel battery any good.

(I had to switch back to mains for a day or so to let the battery recover.)

I added another 12Wp (~10%) to my off-grid panels, switched to a more-efficient DC-to-DC converter, and tuned various parts of the software again to further reduce consumption and 'idle' more when the battery is low.

All in, including the converter, consumption is usually under 4W (difficult to tell exactly given the granularity of my power meter in 100mA increments).

Rgds

Damon

[DamonHD]

My other half is not best pleased about the 60Wp of TopRay solar panels that I bought today from Maplin to supplement my little off-grid system that has been struggling to power my SheevaPlug when we've had a run of cloudy days: basically I want to end every day on the controller's green/full indicator unless we've had a couple of really dreadful days.

I now have a little under 200Wp with about 120Wp facing due south and steeply (~70degrees) inclined to optimise winter collection.  The 120Wp and my MPPT should really cover the below-5W 'quiet' power consumption of the plug.

I did bargain the manager down to their 'offer' price (it's not currently on offer) which is about 1/3rd off the ticket price, so at a little over £3/Wp they are about the cheapest per Wp that I can lay my hands on and I'm happy with other TopRay/Maplin panels that I have.

I expect to put these new panels away in summer when I have lots of other generation and kids romping on the grass given that they are at ground level and contain glass.  And I'll have to move them at least once to mow the grass this week.

I also found evidence of an overheated junction/terminal so I'm probably going to put in some quality rewiring time tomorrow afternoon if possible when I get back from being on a panel discussion where someone has mistaken me for an expert on something!  B^>

Rgds

Damon

[TomW]

HD;

Reality sure bites doesn't it! Between pie in the sky industry ratings and low sun days solar can be downright disappointing. However, when it works it just works which is good.

Tom

[DamonHD]

Well now I've got enough actually facing south I think I should be OK.

Being in a dip and in a leafy suburb doesn't help right now with the trees stubbornly refusing to drop their leaves.  You should see the effect on my roof panels in the morning this month: enough to make you weep even if it is already factored in...

Rgds

Damon

[DamonHD]

Pah!!!

A few very gloomy days and taking the battery right down to 11.4V and no recovery even keeping to switched off for a day or so and I've had to revert to mains power (albeit only 4W!).  I feel dirty.  B^>

Rgds

Damon

[DamonHD]

Finally back into 'green' territory on the Morningstar MPPT display (~12.2V resting) so I'm back on using it for my 3W LED work light at least.

And we're due 80mph (129km/h) winds over the next day, which even in my stupid location should hopefully push the odd Joule in...

Rgds

Damon

[DamonHD]

http://news.bbc.co.uk/1/hi/uk/8358530.stm

[DamonHD]

I gave my batteries a break for a few days and got them fully charged and (so far as I know) happy, and put the SheevaPlug back on solar.

But today I also put in a little DPPT toggle switch so that if the batteries run low I (or someone else with instruction) can flip to the original switch-mode mains supply and have the SheevaPlug run from that (albeit in minimal power ~4W mode).  The mains adaptor is plugged in ready but switched off to save its 'vampire' 0.8W unloaded draw.

I may be going to help with some wind farm prospectors for a few days shortly so I can flip it over to mains before I go and not worry about running out of juice before I go.

Or I can let it ride and have my other half flip things over if the batteries fade.

Decisions decisions...  Should I tempt Murphy?

Rgds

Damon