Existing solar PV install - grid failure ideas??

oojohoo1

Hi,

So, we currently have a 6kw Solis 5G inverter with 2.4kw battery and 7kw of panels.

What would be the best solution to keep power to the house in the event of a power failure?

1. Have a second more basic 6kw or 8kw inverter installed in parallel to our existing one. This would be configured for off grid. Then have a few change over switches installed that we could move the pv panel and battery supply over to it and isolate from the mains also? Have a small generator connected to the AC input to top up the battery as needed?
2. Install a change over switch for just a generator. Probably cheapest option, but then the generator would have to be running full time to keep house powered up.
3. Swap out our existing inverter for one that can switch between on and off grid and has a gen port? I know sunsynk and Solarx have this function but not sure of any other brand with this functionality.
4. Keep existing system but increase to 15kw of battery backup and install a change over switch for the emergency backup port on the solis to switch the whole house supply over to it and hope the power isn't gone for more than 2 days? No guarantee batteries would be full either when the power does go?

Or any other ideas :)?

And just to clarify, we would be isolating the house supply from the mains also with all these options to prevent backfeeding

Thanks.

graememk

Over thinking it a little bit, your first suggestion isnt one. way too much to switch etc

Simplest option (1) - Changeover switch on your current inverter. Will last as long as you have power in batteries. 2.4kWh will not cut it. There is ways of powering the fireman switch in this scenario, so solar can be running when power is off.

More advanced (2)- (was shown a photo of this recently, was a very tidy job)
2 Changeover switches, One to select solar or generator and a second to select backup or grid, It could run from a generator or inverter. Quite a lot of wiring to do this properly, usually means rerouting the main tails into a new consumer unit, Backup feed, and generator feed. (and with above ways to keep solar running too)

Big outages from storms, are predicted so usually you have time to charge the batteries before hand (or keep them charged)

Option 1 with the likes of a sunsynk is also good, as then you can run off grid, run the generator and the sunsynk can charge the batteries from the generator, so the generator doesnt have to run all the time.

the more fancy you go, the harder to find the people to do it but they do exist but the cost may be higher as its not common or run of the mill.

oojohoo1

I didn't realise you could do something with the fireman switch. I suppose the handiest option would be to find an electrican to switch over the AC supply for the switch over to the AC Backup supply. Pv panel should kick in then. Just need to find an electrician :/.

The one grievance I have with sunsynk is I'd have the drop from a 6kw inverter to a 5.5kw inverter.

Would you know of any other inverters other than SunSynk have a gen port?

Any ideas on how you go about finding a sunsynk installer without sending out a mail to 50 installers :(