Date: 24 Sep 89 22:23:46 PDT (Sunday)
From: Bruce Hamilton <Hamilton.osbuSouth@Xerox.COM>
Subject: Yes, the power grid IS getting less reliable
Since the reliability of the power system relates directly to the reliability
of many computer systems, the following info is probably of interest.
I spoke with a friend who used to be in charge of building large power projects
for Southern California Edison (SCE). He said that, due to increasing
competition and decreasing ROI, over the past ten years or so SCE has planned
its power grid to "N-1" standards, whereas previously they planned to "N-2".
"N-1" means they can lose only one major transmission line without a major
system blackout. He added that even "N-1" is marginal in some cases.
Of course, they DID learn a lot from the big (1964?) blackout in the Northeast,
where the system wasn't smart enough to partion itself in the face of
unexpected overloads, and so the whole system went black and huge generator
bearings melted down and were out of commission for months because the power
plants had no UPS's to pump lubricating oil.
Still, my experience is that most blackouts are small, localized ones due to
things like a car knocking down a transformer. We seem to suffer three or four
per year here in El Segundo, CA.
In summary: keep buying those UPS's for your data center.