Dabop
Master Poster
That's why hybrid inverters have inbuilt changeover switches in them- they are designed specifically for the job of being both a gridtie inverter AND safely powering the household loads during a blackout....A friend who just retired to Orkney has such a system. As business resilience had been his work, he knew exactly what he wanted and was able to get the installer to do more than offer a single isolated socket which could stay live. Instead he has a changeover breaker which isolates their house from the mains and enables their inverter to run with no mains to synch to.
Isolation is the big problem of course. If your inverter ran in a power cut, for one thing it would be trying to power the whole district and for another when the mains came back on the two systems wouldn't be in phase and sparks would fly.
This is my own 12kw hybrid inverter (thats running this computer right now lol) being used in its 'offgrid' mode...

It doesn't need an external ATS, as it has one built in from the factory... (ATS is Automatic Transfer Switch)

It has the 'AC input'- that goes to the grid connection....
AC Output is connected to the household fusebox/consumer unit feed point and its loads via the consumer unit...
Like many, mine can be programmed in multiple ways- as an 'emergency backup'- where the AC in is just connected to the AC Out terminals usually, and the PV inputs (6kw of panels) feed back to the grid ie gridtie inverter mode... if the grid fails, then it turns on the inverter and switches the house loads to that, running off its battery bank, which is now being charged by the panels.... at this point the AC in is totally disconnected from the inverters internal supply...no actual connection and no 230v appears on the AC Input
For areas with 'dirty power' ie lots of spikes and surges, it can be run in a similar way, but with the inverter running the loads 24/7, and instead, the inverters internal battery charger circuit is supplying the inverter with power, and keeping the battery 'topped up'- because the inverter is always powering the loads, this is its UPS mode (Uninterruptible Power Supply)- again if the grid fails- it relies on the panels and battery bank to feed the loads... and the grid input is again totally disconnected in this mode whenever it fails- no power can ever go back out the mains input if there is no power there, but it acts like a conventional gridtie and exports excess power once the battery bank is fully charged...
Like many- I'm running a hybrid purely offgrid- its a good way of allowing the battery bank to be charged via a generator if needed without buying a separate battery charger- the panels charge the battery bank up as normal, but if you hook a generator up to the mains input terminals- whenever you start the genny- you can either run the house directly from the genny , or by putting it in UPS mode, you can use a 'dirty generator' to feed the house loads without worrying that you will spike them- the genny simply runs the internal battery charger, and charges the battery bank while running the inverter, which is running the actual house loads...








