"installing UPSes isn't hard"

Clearly you've never owned a UPS the size of a large DC Plant.

One of the ongoing problems with UPS boxes is they have batteries in them,
too, and they have to be managed and maintained.

one of the BIGGEST wins in going with House DC as a source is that
there is just one battery plant to be managed, and it is always rated
for at least 8 hours continuous full load. sizing a UPS for that
much is very, very expensive.

If you wanna run AC, use inverters from House DC. That's just a
UPS with the crap made redunant by a huge DC plant left off.

If you insist on buying AC-powered things, then you will have
inverters somewhere, either inside the UPS box or outside
connected right from the DC plant. EIther way, there are
many more parts involved to break. the MTBF WILL be lower.
there is no way around that.

The Telco folks have 100 years of hard-won experience and some
of it is worth borrowing to prevent learning it the hard way.

But if you insist on relearning them, be my guest. Just don't
offer bad advice to other impressionable young minds.

  -Mike O'Dell
   VP, Chief Scientist
   UUNET Technologies, Inc.