Running a SunFire V100 on Solar Power
This is all a bit of a work in progress. At home I
have a SunFire V100 that lives under the stairs, and
Johanna and I have SunRay client machines. It works
for us.
When things go italic you have reached the
stage of where I am now with the project.
12v SunFire
The SunFire as I have it configured uses about 40W of
power at 240V. To run it from solar power I needed it
to run from a 12V supply. The ever handy
e-bay had
a seller selling some very nice DC-DC boards branded Pico-PSU.
I got the 80W one, more than ample for the SunFire. The documentation
that comes with the Pico PSU claims 96% efficency. I've not calculated
that yet, but it certainly wastes no energy in heat, it runs very cool.
The first job was to make sure it worked:
This involved unplugging the Sun PSU from the motherboard
and plugging the Pico-PSU in, the Sun PSU had to be
dismantled to work out how the power switch worked, thankfully
it was simply wired through the PSU, and so would be easy to
remove.
The next job was to calculate power consumption. I put a
multimeter in the 12V supply feeding the Pico PSU.
I use a old Thinkpad for a terminal, which is what you can see
in the images below. These are the sort of values I was
measuring:
SunFire Consumption (Amps@12V)
------------------------------------------------------
LOM Live, machine off 0.07
PowerOn Self diag 2.34
Kernel Loading 2.69
ZFS Mounts 2.71
System Booted - idling 2.59
The next stage was to have it running in my study on 12V
for a few days to make sure it didn't overheat, misbehave
or any of that sort of thing. It has one fan missing now
because of it not having a PSU, this does not seem to be
a problem.
I ran it from both a 4W 12V PSU "brick" and also from a set
of batteries during the few days:
The last real bit of testing was to see how long the SunFire
would run on a charged set of batteries. I currently have 90Ah
worth of deep cycle batteries. I charged them with a normal
charger and then left the SunFire on, using it at times.
I ran "uptime" every minute and re-directed the output to a file,
if I was in the room I measured the voltage and appended it
to the log, here is the log with the times that I recored the
voltage:
Uptime Voltage
-------------------------------------------------------------------
5:33pm up 2:20, 1 user, load average: 0.09, 0.07, 0.07 12.2
6:02pm up 2:48, 1 user, load average: 0.05, 0.05, 0.05 12.0
7:11pm up 3:58, 1 user, load average: 0.11, 0.07, 0.05 12.0
8:05pm up 4:52, 1 user, load average: 0.25, 0.26, 0.26 11.9
9:41pm up 6:28, 1 user, load average: 0.34, 0.37, 0.37 11.8
4:12am up 12:59, 1 user, load average: 0.35, 0.36, 0.36
The machine lasted 10:45 from 90Ah. A useful thing to know.
Making the 12V Supply Tidy
Now I had finished geeking with the machine, it was time to tidy
up the supply as the next stage really is external to the machine.
I took one old Sun mouse mat (keeping with the Sun theme!), and with
a pair of tin snips cut out a panel to fit where the mains PSU had
one been. The tin snips made easy work out of the mousemat! The
next step was to cut out a hole for the power supply and on off
switch:
And then power off the Sunray and solder everything
up tidily and put it back together again:
And the job done:
Charge Control
The charge controller should arrive from Ebay any
day now. I hope to use a K8055 and some code to
monitor the state of the batteries and then if needs
be (hope not!) flip over to a mains derived 12V supply.
Until I get the panels I'll be running from mains derived
12V.
The charge controller has a set of status LEDs that I
wanted the V100 to monitro - mainly so I can check the
battery is ok, but also for the geek value of plotting
when I am charging and the like. It was a simple matter
to hack at the electronics of the charge controller,
basically picking up the voltage driving the LEDs, however
this comes out as a common a +5v. To get around the problem
I created a circuit that uses some opto-isolators to convert
the signals into something the K8055 understands.
The schematic, and the PCB are below:
What the inputs and outputs are
With the PCB built I then modified the K8055 demo code
to read the values from the K8055.
k8055 code
The code also switches one of the digital outputs to turn
over to using mains supplu if needed, this is a simple
circuit with a relay in it:
Circuit
Photos
Running From Solar
As soon as I have saved my pennies .... I'll be getting
some solar panels and will hook them up to the charge
controller. I've got the K8055 sort of detecting voltage,
and have some C that sort of works:
Costs (*gulp*)
All in UKP. I'll add to this as time and money goes on.
Purchase Cost
------------------------------------------------------
3 * SunRay 1 0 (already had them)
1 * SunFire V100 50 (Ebay)
1 * PicoPSU 25 (Ebay)
1 * 10A Charge Controller 15 (Ebay)
1 * 20W Solar Panel 82 (Ebay, 18 was postage)
Equiv. 90Ah Battery 0 (Found in Shed)
1 * 6mm SAW Cable (10m) 22
1 * K8055 Board 0 (already had it)
----------------------
184
Now, if I had to buy everything from scratch now(!):
Purchase Cost
------------------------------------------------------
3 * SunRay 1 100 (Ebay)
1 * SunFire V100 50 (Ebay)
1 * PicoPSU 25 (Ebay)
1 * 10A Charge Controller 15 (Ebay)
1 * 20W Solar Panel 82 (Ebay, 18 was postage)
Equiv. 90Ah Battery 157 (barden-ukshop)
1 * 6mm SAW Cable (10m) 22 (City Electrics)
1 * K8055 Board 30 (Maplin)
----------------------
481
I suspect in the end it will be cheaper to use mains power, but
running Solaris from solar power cheers the geek in me up!
Thanks
Mark Neal - Handy advice on batteries and Solar "stuff".
Les Dean - Handy advice on the electronics side.