WSJ: Big tech firms seeking power

Sat Jun 17 04:41:13 UTC 2006

On Fri, 16 Jun 2006, David Lesher wrote:

> who insist on perpetuating that most medieval of units... the BTU.

Well, if you do away with that you can continue with the "mile" as well, 
then lose the pounds and yards and gallons while you're at it.

On the other hand, I have a question I was pondering at the nanog power 
session (which was a really good one).

What is the amount of energy coming out of a server as heat as opposed to 
what you put in as electricity? My guess would be pretty close to 100%, 
but is it really so? And I've also been told that you need approx 1/3 of 
the energy taken out thru cooling to cool it? So that would mean that to 
sustain a 100W server you really need approx 130-140W of power when 
cooling is included in the equation. Is this a correct assumption?

In one of our data centers we use community cooling, we get 4 C (I think 
it was approx 4 C) degree water and we're required to heat it at least by 
8 C before we return it, this is then used in the community power plant to 
produce hot community water, and this process I've been told is quite 
effective. Any thoughts on this? Guess it doesn't work in the boondocks 
though...

There were also plans to use heat converters to have the cooling water 
from nuclear power plants heat community hot water, but politicians 
chickened out. Now we just spew that cooling water straight out into the 
ocean.

I guess none of this makes sense in the southern part of the US, but 
further up north where houses actually need heating and not cooling most 
of the year, are things like this done?

-- 
Mikael Abrahamsson email: swmike at swm.pp.se