BrettS
Active Member
If so, and assuming there were a Scheduled Outage by the utility starting in the morning (~8am) and ending in the late afternoon (~5pm), would it be advisable to switch over to Self-Powered say 20minutes in advance of the scheduled outage and then revert to backup mode once said outage is over?
You certainly could do that. As I said above, in my experience, the switchover is still pretty minimal. The lights might quickly flash, but that’s about it. I personally probably wouldn’t worry about it. They say that it can take up to an hour for the powerwalls to switch modes, but it seems that it typically happens within a couple of minutes.
B) Given the PV is being instructed to “Shut Off” when an outage occurs due to there not being sufficient excess capacity in the PWs to absorb the excess PV production, what would be expected to occur should the home be drawing the full production of the PV AND drawing from the grid (i.e. the home electricity demand is higher than the current PV output in this moment) when an outage occurs in backup mode?
Whether the solar switches off depends entirely on the state of charge of your powerwalls. If you are in backup only mode, then your powerwalls should be fully charged. In that case, then when the outage occurs the solar will shut off and the house will be powered entirely by the powerwalls. After a short time, once the powerwalls get down to about 97% the inverters will come back online and your house will be powered by PV and the powerwalls, assuming that your house is still drawing more than the PV output. Or PV only if your house is drawing less than the PV output, with the excess going to charging the powerwalls.
However, if for some reason your powerwalls have less than a full charge (are at about 97% or less) at the time of the outage, then the inverters will not be shut off and solar will continue producing. If you are producing excess solar power and your powerwalls continue to charge, then the inverters will be shut off as soon as the powerwalls get up to about 98%, then once the powerwalls get back down to about 97% the inverters will come on again.
So just to clarify, we are saying that it’s normal for your inverters to shut off when an outage starts simply because you are in backup only mode and that keeps your powerwalls at a full charge.