"Kenneth" wrote

Beyond that, the standard "battery backup" units for the
sump pump seem to have a run time on the order of 15-20
hours and I recall an ice storm in which we lost power for
more than 96 hours.

Further threads provided additional info Application.

Years ago, we sold a mini SCADA unit designed spefifically for this
type application.

You would monitor the incoming power.

If it would fail, a contact would close, then call you and announce
the power was out.

It could also close a contact to electrically start a generator.

Found a lot a application in Canada for monitoring telecommunication
facilities out in the boonies that were only accessible by helo in the
winter.

This is at least 20 year old technology and had about a $3K cost back
then.

Today, the net will have revolutionized SCADA systems.

Try a Google for SCADA and see if small systems are still offered.

Lew