[Cialug] [omaha] Google Datacenters

[Stuart Thiessen]

Regarding this, it sparked a question that I have wondered about ...  
at least once a year, I go to different locations in Africa, and I do  
some work there. The group I work with does not have a backup  
generator at their location. African electricity is not always  
"consistent". :) So, I've wondered what would be the best way to have  
a longer-lasting backup battery (than just carrying a charged spare  
laptop battery) so that I could work longer even when power is out.  
Flying out there with a UPS is probably not a weight efficient  
alternative. Would you guys have any suggestions?

I'm using a MacBook Pro if that helps any.

Thanks,

Stuart

On Apr 10, 2009, at 11:22 , <murraymckee at wellsfargo.com> <murraymckee at wellsfargo.com 
 > wrote:

> I was thinking that it would be really useful to have 12V power  
> connections on my desktop and monitor so I could just hook up an  
> extra car battery during power outages as a UPS.  Then when it got  
> low you could just take it back out an hook it back up to the car to  
> recharge it.  Unfortunately my laptop runs on 20V so I doubt it  
> would work if I fed it 12V, and might never work again if I  
> connected two in series and fed it 24V.
>
> Murray McKee
> Operating Systems Engineer
> WFFIS - Wells Fargo Financial Information Systems
> 800 Walnut Street
> MAC F4030-037
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> -----Original Message-----
> From: cialug-bounces at cialug.org [mailto:cialug-bounces at cialug.org]  
> On Behalf Of Daniel A. Ramaley
> Sent: Friday, April 10, 2009 11:08 AM
> To: Central Iowa Linux Users Group
> Subject: Re: [Cialug] [omaha] Google Datacenters
>
> Possible? Of course. Practical? I don't know.
>
> You need very thick wires (thick inch-thick bars of metal) to carry
> enough current at 12V if the distance spaned is very far. If the wires
> are too thin, they will have too high a resistance and drop too much  
> of
> the potential. If the wires are really too thin, they will get hot and
> melt. Making thick enough wires out of copper might be prohibitively
> expensive. Cheaper metals that don't conduct as well would require  
> even
> thicker wires. Of course, if you have a room temperature  
> superconductor
> (presumably made of unobtainium), then it might be more feasible.  
> But i
> don't know much about superconductors; they might have limits on how
> much current they can carry too.
>
> People with more electrical knowledge please correct me if necessary.
>
> On 2009-04-10 at 10:49:09, jrnosee at gmail.com wrote:
>> I've often wondered if it would be possible to convert AC to 12VDC  
>> for
>> the entire datacenter then run 12V lines to each server and only have
>> a DC->DC 12V/5V/3.3V Point of Load power supply do the conversion.
>> Thus eliminating power loss in the multiple AC-DC conversions and
>> running all the extra power supply fans, etc.
>
> ------------------------------------------------------------------------
> Dan Ramaley                            Dial Center 118, Drake  
> University
> Network Programmer/Analyst             2407 Carpenter Ave
> +1 515 271-4540                        Des Moines IA 50311 USA
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