So we have been running at between 242V and 252V for years... (Australian standard voltage is supposed to be 230V +/-10%)
Yesterday we had an all day scheduled maintenance power outage....
After power came back on, the Voltage was down at 236V - lower than I have seen it in 10 years of keeping an eye on it (ever since I got a glorified multi-plug unit combo surge-protector with a readout of the voltage! - Belkin Pure-AV PF60) - today, on a bright sunny day (on the cusp of autumn) - the Voltage is up to 242.5V.... but 2 days ago under similar conditions (peak solar panel output time) - it would have been between 248V and 252V.
Very happy to see the voltage at a more reasonable level - would like it to actually approach the standard of 230V - but I guess that won't happen until/unless I make my home grid independent.