After two days of very little sun my off-grid solar system shut itself down for a few hours just before dawn. Not a big deal, it came back up this morning once there was sun on the solar panels.
But... my web server is an old laptop, and the outage was long enough that it shut itself down. I'm 400 miles from home and there is no one there to punch the button to start it up again. I guess that I'll need to replace the laptop with a machine that supports boot on power restore.
@daniel
Problem solved!