Can Hybrid Inverter act as AC Coupled Inverter

It may seem like an odd thing to do BUT, I have an existing solar PV set up. I would like to add a Hybrid inverter and battery to it but would rather NOT replace the exisiting inverter for FIT reasons.
If the Hybrid was installed without Solar panels, would it just act like an AC Coupled inverter; detect when export was occuring, and use that to charge the battery? or can a Hybrid only charge from DC or when timed to charge from grid regardless of import/export.
If I did replace the existing inverter with the Hybrid but kept the existing capacity of Solar Panels, would that scupper my FIT as presumably, though I wouldn't, I could charge and discharge the battery from the grid and that would show up on the generation meter.
Thoughts ?

kwmc Accepting that you want to leave the existing FIT installation well alone, I think your question is "how can I use a hybrid inverter to charge a battery from energy that would otherwise be exported?"

The Givenergy Hybrid can monitor import/export but I don't think there's a mode to set it to charge the battery from the grid other than by a timed charge. You could manually set it to charge "from the grid" when you know the existing PV is exporting but if clouds pass over you'd have to manually stop the charge.

The other way you could do it is to monitor the export with another device such as a Raspberry Pi (connected to an EM115 would give you accurate data, I think @Seye has done this) and then use Node-RED or something to switch the inverter on and off. The only thing is that I don't know how well you can control the rate at which it would draw energy to charge the battery.

What you really need is a Zappi and an EV to soak up your export!

As far as I know changing the inverter will generate a new MCS certificate which would cancel your FIT.

I maybe missing the point but why not just add an AC Inverter and battery to the existing panel / inverter setup? With that you get the best of both worlds - FIT from existing system and ac inverter to charge the battery from excess...

THALL That's interesting, so current question aside - if my inverter packs in and I replace it does that cancel my FIT ? I hope not. I thought it was only if I added more panels to the system or increased it's capacity, that my FIT woul change proportionately but not be cancelled

locked Using an AC Coupled inverter would be best but I may have access to hybrid and wonder whther I should replace the exisiting inverter with the hybrid or can configure it as an AC Coupled inverter just not using the PV inputs.

kwmc That would be a question for an installer to confirm. But I would guess an out of warranty replacement so a different make and model would void the FIT.

It would be reasonable for the FIT to be cancelled on the installation of an AC coupled inverter and batteries. After all, that would completely negate the concept of 50% deemed exports...

Would you not have to inform someone first? I know a couple of people with FIT/batteries/off peak tariff etc. And I know for sure that they have replaced failed inverters along the way.

I was under the impression providing you don't fundamentally change anything that affects the metered system output (i.e add more panels, BIGGER inverter) you could exchange equipment / inverter under FIT for a comparable output one (i.e 3.6kW Growatt for a 3.6kW Givenergy) no problem - it would be unlikely for the original inverter to make it to 20 year mark anyway.

I believe you could even add DC Coupled battery storage behind the FIT meter (so long as it couldn't be charged from AC all your doing is deferring the output anyway) - I even use one of these now on my non FIT install.
Adding a new hybrid with storage capable of AC charge from my take would be a big no no.

Another Hybrid & panels or just AC coupled AFTER the Fit meter would however be fine to hoover up export though.
It's not really any different to adding a Solar Diverter to take away some of the excess.

Since one is allowed to use as much of the generated power as one wants AFTER the generation meter, AC coupled inverters are just another appliance. One is deemed to export 50% but you don't need to and it is not metered. AC coupled inverters are intended to work alongside existing Solar PV without affecting FIT. I'm fortunate that the original inverter is still doing its stuff after 11 years of service. In some ways an AC coupled inverter is just another diverter only it stores electricity rather than hot water. You can heat water with gas at much less cost than using electricty which, if you can store it as electricity is worth much more to you than hot water

kwmc exactly this. As long as the FiT system isn't touched, then adding an AC inverter and batteries is just another "house load" really. You do have to inform you're FiT provider of a battery install - I think largely they just want confirmation the battery install hasn't been wired in so as to "pollute" the generation meter (which a hybrid set up would).