Almost everything that looks wrong in your solar app during load shedding is the grid's absence showing up as missing data, not a fault in your system. A grid-tied inverter is built to stop producing the moment the supply drops, so its zero is correct behaviour. A hybrid inverter is built to keep running, which means the readings worth your attention shift from daily yield to state of charge and load draw. Put every number on that screen into one of two piles — artefacts of a dead grid, or figures that still carry information — and the outage stops looking like an emergency.
I do that sorting at 20:04 on a Stage 4 night, standing in the kitchen with the phone in one hand and the fridge door shut, because I have learned not to open it. The app has refreshed twice. PV power: 0 W. Load: 340 W. Grid voltage: blank. Frequency: stuck at 50.00 Hz, which is the last thing it measured before the supply went. Battery state of charge: 78%, drifting down. My gut still says something has broken. It hasn't. I am reading a screen full of the grid's obituary.
Pile one: readings that are only the grid being gone
Zero production is the first one, and it is the one that catches people every time. If your inverter is grid-tied, or a hybrid running in a grid-following mode, anti-islanding is not optional — NRS 097-2-1 requires it to disconnect from the municipal supply when the supply disappears, and the same requirement sits behind your SSEG approval. That disconnect is the reason the panels go quiet. Zero watts at 20:04 is the system obeying the law, not failing to do its job.
Grid voltage is the next one. On some apps the tile empties. On others it holds the last value it saw, frozen, with no timestamp to tell you it has stopped updating. Frequency does the same thing. Both of these look like damage. Neither is. A sensor with nothing to measure does not report zero volts — it reports nothing, or it reports the last thing it knew. Zero volts and no volts are different conditions, and most apps never bother to say which one you are looking at.
Then there is the daily yield curve, which does a cliff-edge drop and leaves a flat section behind it. And the export reading sitting at zero, which it will, because there is nothing to export to.
Nothing in that pile tells you anything about the health of your panels, your battery or your inverter. It tells you the municipal supply is off. That is all.
Pile two: the figures that still mean something
When the grid goes, the useful information moves. It moves to state of charge first, load draw second, and battery discharge power third. Everything else on the screen is background.
State of charge is the obvious one, but the number is less useful than its slope. 78% means very little on its own. 78% falling to 61% in forty minutes tells you the household is pulling hard. 78% falling to 74% over the same forty minutes tells you it barely is.
Load draw is what explains that slope, and it is the reading I check first now. Watts out of the battery, right now, with the kettle and the air fryer going, is a completely different figure from watts out with the lights, the fibre router, the TV and a phone charger. Your inverter is not producing less in the second case. Your house is simply asking for less.
Discharge power, and any time-to-empty estimate your app calculates, sit in the same pile. Treat the estimate as a rough projection built on the draw at that instant. It will swing. That is the arithmetic doing its job, not the app lying to you.
Same house, same outage, two different curves
This is the thing that confused me for longer than I want to admit. Two Stage 4 slots, both two hours and fifteen minutes, and the state of charge curve came out completely different. First night: kettle, microwave, tumble dryer finished before the outage, dishwasher running. Second night: everyone asleep by 21:00, only the router and the fridge running.
The first night dropped 31 percentage points. The second dropped nine. Same battery, same inverter, same roof. If I had looked only at state of charge I would have concluded the battery was degrading. Overlaying the load draw graph on top of it made the whole thing obvious — state of charge is a consequence. Load is the cause. Watch the cause and the consequence stops looking erratic.
Why your history graph has holes in it
The next morning, the history view usually shows a gap or a flat stretch across the outage window. People read that as downtime.
Usually it is the logging, not the system. If your router sits on the backup circuit, logging carries on and you get a clean record. If it sits on the non-essential side, the inverter keeps working all night while the data simply stops arriving. The system was fine. The thing writing down what it did was not powered.
Timestamps can drift too, because the inverter's clock often syncs from the grid or from the internet, and one of those just vanished. A block of readings stamped an hour out of place is a time-sync artefact, not a recording of something strange happening on your roof.
The one entry worth writing down
Inverters log a grid-loss event when the supply drops, usually with a warning code attached. That log entry is the only piece of the whole picture that deserves a second look, and the only reliable way to interpret it is against the manufacturer's own documentation for your model.
So I write it down. Code, time, date, nothing else. I don't go into settings mid-outage, and I don't touch the data logging. When the power is back and I have a browser open, I look the code up in the manual and read what the manufacturer says it means. Nine times out of ten it is the grid-loss notification, which is exactly what the entry is supposed to be.
That is the discipline: the code goes in the notebook, the manual does the interpreting. Not the app's red banner, and not my mood at 20:04.
What I actually do now
When the lights go, I give the app two minutes and then read it in a fixed order. Load draw first. State of charge slope second. Event log last, and only to copy the code out.
I ignore PV production entirely if the system is grid-tied, and I ignore grid voltage and frequency whether it is grid-tied or hybrid. I ignore the shape of the yield curve, and I ignore the gap in tomorrow's history view until I can check whether the router is on the backup circuit.
By 22:30 the state of charge is at 54% and the screen looks exactly as alarming as it did at 20:04. Nothing has gone wrong. The house is running, the fridge is cold, the router is up. Sorting the numbers into the two piles is the whole trick, and it turns a night of quiet panic into a night of reading two graphs and going to bed.
