I can only offer this. I think you'll be best off to find the loads that
run 24/7 and concentrate on
reducing them. Even a small improvement helps a lot with 24/7 loads. This
is obviously your
computer equipment. Can computing tasks be concentrated to a single
computer at certain times of
they day so another could be shutdown or at least put in power save mode?
Are you utilizing the
power saving features of the OS? Is it possible to buy a single larger
computer instead of several
smaller ones? Can you use a different type of disk drive that that allows
you to use fewer but
faster disk drives (SCSI or Fiber Channel)? Are there interface boards in
your computer that you
don't use that can be removed? Can you use fewer monitors and use a video
switch or KVM to allow
them to go away (or at least be powered totally off 99% of the time)?

I have tried to engage the power saving mode, but the PCs don't wake up
properly. Wacom, the maker of the drawing tablets, for instance, just
advised us to disable power saving mode, rather than fix their driver. I
didn't harp on it because there are few times these boxes are idle.
We've invested $2800 on each machine recently and they are under a year old,
with a five-year amortization before we even THINK about going through
another complex upgrade.
I used to run everything on one machine, but there were too many
cross-conflicts. We learned some important lessons and diversified the
machines (some MIDI/DAW hardware conflicts with Quadrant MPEG decoder
boards, and you really don't want to be rendering 3D animation in the
background while you're burning DVDs.)
We have only the minimum of interface boards we need. I am from the "KISS"
school of thought, because simple configurations result in less IRQ conflict
problems. As for disk space, I bought the largest discs that are considered
reliable and compatible with our mainboards (120GB drives in RAID0 pairs).
It hadn't occured to me either that the 3D accelerator cards used in the two
most powerful machines each use about 75W of power as well.
The monitors are basically off most of the time (they run cold on standby
and the current draw is at a trickle). My wife's which is an older NEC 5FG,
just gets turned off at night when she's not using it. KVM switches were
once something I looked into, but many of them aren't spec'd to work above
1600x1200, and the computer workstations are situated too far apart.
I don't think there is too much more that can be done about the consumption
angle. Believe me, I've been thinking about this since last summer, when we
made the upgrade from Pentiums to Athlon XPs and noted the increase in room
temperature, followed by the increase in electric bill.
The remaining solution is to look at alternate power sources for some or
most of the operating period.



The only other thing I can see from a system point of view is that the
computer is driven by DC. You
have losses in the power supply converting the AC to DC. You have even
more losses since you're
using a UPS going from AC to DC to AC and then the computer goes to DC. I
don't know if you could
buy a power supply or would have to make it (since you need multiple
voltages at a rather heavy
current), but a DC battery system that provides DC to your computers may
save some conversion
losses. Solar generation is also DC and you could gain some free
electricity that way.

This has up to a 20% advantage due to elimination of conversion loss, but
the complication of externalizing all those power leads probably brings more
risks than benefits and would be expensive and complicated to implement.
Therefore, my solution has to be able to convert solar to 120VAC.



I'd focus on finding a way to get external free DC into the UPS battery
system or a separate
computer power supply. If you add a lot of battery capacity, you may be
able to rig a controller
that removes AC from the UPS and runs off the batteries. Do this when the
sun is just beginning to
shine and continue to run from the batteries until they are some percent
depleted (perhaps 40%?). At
that point, switch the AC back on to charge them back up. Finding an off
the shelf system that works
well this way may be a challenge. But the hoepower people may have
equipment that works more for
what you're trying to do rather than a UPS.

If you only improve the computer power system by 20%, your overall power
bill will probably be
reduced by about 15%.

Possibly some savings could result if I could trickle charge the UPS off
solar, but I think the results would be so small as to be negligable.
Now if I ran everything off an inverter, things might be different.
Or maybe I could just take up golf and forget about computing. :-)


--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
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