Updated on 18/12/25 by Chris_OVO
Guessing here: a smart meter should retain much of the data it collects in non-volatile memory. A power cut should raise flags (start and stop) so that any data collector will know why data are missing from the sequence. I’ve no inkling of how a power outage would affect meters connected to off-grid sources - your PV array, for example. The meter will presumably continue to operate, though, whether that’s by its backup battery or (in your case) solar power.
I suppose it varies from collector to collector how they react to power cut flags, but I’m prepared to bet that it will take time for their data to look anything like normal again.
The Aclara SGM 1400 manual I referred to recently might help you fathom this out.