Will your PV array work when there is a power cut?

Calahonda52

Am getting different answers.

I know the array has to isolate from the grid but will it still work as if it were an off grid installation?.

Thanks as always

ELM327

NO.

No unless you install it in such a way to do so, and as such would not get the grant. Look up AC Coupled Inverters

unkel

You will get different answers here too, because the answer is both yes and no 😁

No for conventional inverters. But yes for most hybrid inverters and battery inverters as they have an emergency AC output, which WILL work but only when the grid is down.

ELM327

https://www.boards.ie/discussion/comment/119645692#Comment_119645692

that emergency outlet only works when the grid is out, and can only handle 13 amps on solis anyway.

In order for it to work properly you'd need a victron quattro or multiplus apparently as these are designed to support UPS/Off Grid transfer on the same output as the grid tied output

graememk

https://www.boards.ie/discussion/comment/119645757#Comment_119645757

On the solis the Backup AC outlet is always live. and on the 5G ones it should be able to output 5kw..

Sofar me3000 backup supply only goes live on grid outages.

ELM327

Must be a setup option then. Mine is not active in normal case - just tested there.

Edit:

Just checked the manual for my 5G inverter. It's rated for 3000w only, and 16a only

Solis_Manual_RHI(3-6)K_5G_ENX_V1.1(20200721)260501054200.cdr (solartricity.ie)

Jonathan

https://www.boards.ie/discussion/comment/119645825#Comment_119645825

Solis 5G 4.6kW and higher inverters have a 5kW backup output. As Graeme says, it is always live.

Sounds like you were mis-sold a 3.6kW inverter if it only has a 3kW output.

ELM327

No, I see it further down, theres a 5kW backup output. You have to enable it in the menu - which I've now done.

There's only 2 3 pin plugs on it currently. Is it possible to change this by unplugging the cables from the mains input and putting it to the backup

Jonathan

https://www.boards.ie/discussion/comment/119645961#Comment_119645961

What are you trying to achive? You shouldn't backfeed an inverter its own EPS output as a pseudo grid connection.

con747

OP what you need is a changeover switch fitted so you can use battery power to run your base load.

ELM327

https://www.boards.ie/discussion/comment/119645974#Comment_119645974

Perhaps I didnt explain my question well, I am a noob at this very much.

I'm looking to include an off grid operation too. I already have a generator which I will run on a changeover switch, but would like something similar for the inverter

graememk

https://www.boards.ie/discussion/comment/119646047#Comment_119646047

The way my dad's changeover switch is wired, The backup is wired into the changeover switch.

At the inverter there is also a MCB to enable power to the changeover, when this is enabled it also energises a NC contactor, which breaks the Mains grid feed to the inverter. (so not to feed its own power). House then is in off grid mode. (fireman switch too)

steps are : Move Changeover switch to the middle, (off)

Flick backup mcb at inverter

Move changeover switch to backup.

You possibly could Have a changeover, before your changeover. to switch your backup modes (although id be wary of putting generator power into the hybrid inverters.... beyond my knowledge there.)

slave1

Yes/No/Depends, AC coupled inverter (which a few of us have) is easy peasy via a hard wired double socket, I can then run the router, TV, laptop, circulation pump etc from this.

As Con pointed out, a changeover switch is the proper job but I don't see the expense as being justified for me given I can run as above on the extremely rare times we are without Grid

ELM327

https://www.boards.ie/discussion/comment/119646128#Comment_119646128

Makes sense. I havent actually got the changeover switch for the generator wired yet, so I will mention that to the electrician and see if I can have a combined switch to include backup mode operation for the solis.

https://www.boards.ie/discussion/comment/119646159#Comment_119646159

Where have you connected the AC coupled inverter? I've got my eyes on a victron quattro as a main inverter and moving my solis to a non hybrid application. PV into the solis, solis into the victron, batteries & grid connected to victron.

silver_sky

I must check what my 6kW Solis is set at. I have the changeover switch like graememk mentions above. I do wonder if the cabling for the backup would be rated for 5kW so I'd be hesitant to switch that without confirming.

slave1

"Where have you connected the AC coupled inverter? I've got my eyes on a victron quattro as a main inverter and moving my solis to a non hybrid application. PV into the solis, solis into the victron, batteries & grid connected to victron."

I've string inverters in Attic (neither are hybrid) and batteries/Sofar right beside Consumer Unit so Sofar is awaiting connection to Consumer Unit

Calahonda52

https://www.boards.ie/discussion/2058264301/will-your-pv-array-work-when-there-is-a-power-cut

Did'nt mean to poke the bear here :)

Thanks for all the discussion.

So to summarise: in a power cut:

1 SEAI grant aided Panels with plain vanilla inverter with no battery will not work.

2 Panels with hybrid inverters with no battery will work in a power cut, but no grant available

3 Panels with hybrid inverters and battery will work in a power cut, but no grant available

4 SEAI grant aided Panels with plain vanilla inverter with no battery, with a change over switch will work.

pls correct

unkel

I just built a 2kWh battery for my bike. Well more like 1kWh, those Chinese specs can't be trusted. Anyway it's more than enough to roast a medium size chicken and a large portion of chips in the double airfryer in the very rare event of a grid outage lasting more than a few minutes here in Dublin 😂 Or give a range of about 100km on the bike without the need to pedal, even for this 100kg+ lad 😁

@ELM327 - if you're thinking of selling that hybrid 5kW Solis, let me know, I'm looking for one. Well ideally I want a 6G one that can charge at 125A, but they won't be around until nearly next summer. If I get a hybrid inverter, I will be selling my Sofar ME3000SP. Or I could do some sort of deal with someone looking to change the other way around.

con747

https://www.boards.ie/discussion/comment/119646446#Comment_119646446

What most people do is wait until the chance of an SEAI inspection has passed 4-5 months after getting the grant and then install the changeover switch.

graememk

https://www.boards.ie/discussion/comment/119646446#Comment_119646446

I think you need a hybrid inverter with a battery to have some sort of backup. But open for correction.

The Seai rules have been clarified recently and in their rules, the fireman switch must not be part of the backup power.

House can be run from batteries only.

Once the grant is completed... There's nothing stopping you from changing it.

unkel

Are the PV subsidies still going? Seems insane now we have a generous FIT?

ELM327

https://www.boards.ie/discussion/comment/119646588#Comment_119646588

lol. Always after a bargain. I'll take a fluence in part exchange.

As con747 says below, I'm waiting until the chance of an SEAI grant inspection passes before making any substantial changes. After that though it'll be all systems go (I plan on spending the grant money on the quattro!)

https://www.boards.ie/discussion/comment/119646654#Comment_119646654

unkel

Best of luck with your system @ELM327!

Wish I had a big house with a big roof and some land (preferably with a stream!), I would have a mahoosive renewable setup for sure 😁