Availability of Natural Gas during Blackout

Sun Aug 17 15:07:01 UTC 2003

There are a couple of problems with Natural Gas generators:

1. It takes an aweful lot of pressure to get a NG engine up past enough HP
to generate more than say 150KW.  At least thats what we have seen with
current models.  It seems to be an issue of pressure, and whether being fed
from a pipeline or coming from a tank separte (electric) compressors are
almost always needed.

2. In times of weather emergencies, snow and excessive cold, the gas
companies routinely shut down gas flow to non-residential areas (like where
you would put datacenters) to assure heat for people's homes.  This bit me
personally in a a very minor way a few years back in a region as far south
as McLean, VA.  We had a small kitchen with a gas stove in the office and
when we got snowed in one night it was shut off.  If the gas supply had been
powering the backup generator for our datacenter it would have been ugly as
the electrical power went out a few hours later.

On the other hand, LNG in tanks is a bit more reliable in the snow if you
have a large enough tank to provide pressure during cold whether and to get
you by during a prolonged snow emergency.  In our transmission shelters
which are spaced aout 50 miles apart along the fiber right of way, we always
try and use LNG generators because they don't have cold start problems the
way diesels do, they just fire up.  And the power needs for the repeater
stations in < 65kw so we dont need to worry about the limit in size on LNG
engines.

-vb

----- Original Message ----- 
From: "Randy Neals (ORION)" <randy.neals at orion.on.ca>
To: <nanog at nanog.org>
Sent: Sunday, August 17, 2003 10:51 AM
Subject: Availability of Natural Gas during Blackout

>
> Some weeks back there was a dicussion on the merits of naural gas versus
> diesel generators.
>
> It is my observation that Natural Gas continued to be available throught
> this recent blackout.
> In speaking to a friend who works for the gas company he informed me that
> the compressor stations on the main pipelines are driven by gas turbines,
> thus they don't require electrical power to operate.
> All telemetering/control equipment on the distribution network is either
> passive, or equipped with natural gas generators to ensure it operates.
>
> Did others notice if there was a gas interuption in your area during the
> blackout ?
> (A lot of people here were cooking on their Nat. gas bbque here)
>
> This was an exceptionally long blackout, did people have trouble getting
> diesel fuel replenished?
> Fuel trucks where no doubt having difficulty with traffic congestion due
to
> traffic lights not working.
>
> Regards,
> Randy
>
>