Re: Looking for advice on datacenter electrical/generator

[Daniel Senie <dts () senie com>]

At 07:42 PM 4/4/2003, Stephen Sprunk wrote:

> Thus spake "Bill Woodcock" <woody () pch net>
> >       On Fri, 4 Apr 2003, Matthew Kaufman wrote:
> >     > natural gas has been off for multiple days in a row twice.
> >     > So for the last datacenter I built, I went with diesel.
> >
> > I'm not following your logic...  How does the fact that natural gas
> > is _usually_ available on-tap, and diesel _never_ is make diesel
> > preferable?
>
> As noted by other posters, natural gas often goes out at the same times as
> electricity in some areas (e.g. California).  In fact, many power companies
> use natural gas to generate electricity.
>
> Relying on one public utility to supplant another is not logical unless
> either you have historical data to satisfy you that outages in one are
> rarely linked to the other, or you can store natural gas onsite to run "long
> enough" and only need the utility to refill later.

It's quite as simple to store propane as it is diesel. Propane stored 
on-site is stable, needs no cleaning, and the genset is the same as you'd 
use for natural gas. Given the choice between storing a large quantity of 
diesel and storing a large quantity of propane, I'd take propane. Other 
folks would argue the other way. Scared about fire reaching your propane 
tank? Use in-ground tanks. Unlike fuel oil or gasoline, buried propane 
tanks are allowed, at least in some places. Think about it... leaking 
propane tanks don't pollute the soil, they pollute the air.

Though I'm in an area where interruption of gas service isn't really a 
problem, the availability of gas is. Some towns just don't have gas 
service. So, we store propane. Not a big deal.

I suspect, though I've never seen it done, that it'd be possible to set up 
a gas genset with both a pressurized tank of fuel and a connection to the 
mains, with valves to switch between.