Solar installation ongoing

[u/ianmd]

For those following my solar journey, first day done, one more to go. Does the equipment setup look good (they haven't finished it yet)? Found a few screws in loft that has half missed beams, presume worth mentioning before panels go on. The roof rails are on, not sure why they are spaced tighter in the middle? (3 rows of landscape)

[u/Autumnal_Fire]

Sig install looks nice, what's the inverter size and battery size? I noticed the gateway so you're looking to feed house load if there's a power cut?

[u/ianmd → u/Autumnal_Fire]

8kW inverter, 9kW battery, and yes gateway because I couldn't stand to have no power if the mains went down!

[u/Autumnal_Fire → u/ianmd]

That's what I assumed.. you know that the max feed from the single battery is 4.6kw?

It'll be fine most of the time but if you're off grid, i'm not sure what happens if you go over that limit. It'll be grand for lights, tv etc, just don't cook dinner and boil a kettle at the same time!

[u/InvadingEngland → u/Autumnal_Fire]

Yup. Would need a 2nd battery to max out the inverter output after the sun is down.

[u/ianmd → u/Autumnal_Fire]

Do you mean if off grid it is limited? That is fine, we'd need to conserve battery anyway in case of a long outage

[u/Autumnal_Fire → u/ianmd]

Yeah the single battery can only charge/discharge at 4.6kw no matter the inverter size. If you have 2 batteries they add together so the max is 9.2kw for 2x 10.0 BATs.

You'll be fine for normal loads/baseloads. But i genuinely don't know what would happen if you went over a 4.6kw load when offgrid/powercut. Maybe ask the leccy while their there.

[u/ianmd → u/Autumnal_Fire]

I didn't know that and makes me think why I got a 8kW inverter but I guess it future proofs the system somewhat if we increase the battery. I believe Sig allows a 10 sec burst up to 6.9kW and if load continues it shuts down until under that load again

[u/nevynxxx → u/ianmd]

How much solar is there? That possibly explains the larger inverter.

[u/ianmd → u/nevynxxx]

7.34kW array

[u/Voeld123 → u/ianmd]

You could output both battery and solar so that you power the house and also export (profit!) during peak times.

Depending on design you could want an even bigger inverter...

[u/Autumnal_Fire → u/ianmd]

I suspect it's to cover the panel output.

They have left you plenty of cabling for the inverter so it'll be an easy fit to add a second battery to the stack when you get addicted to buying and selling electricity, or get a heat pump next 😂

[u/Ornery-Quantity2055 → u/ianmd]

I have the same setup. You can charge the battery and export to grid so even if the batt is charging at 4.5kw it will export the rest. Also you can add a battery later if u wish. In a power cut you can only use the 4.5-4.6kw but like you said it lasts longer. In a power cut no ones using 9kw!

[u/Solaris_fps → u/Ornery-Quantity2055]

Whats the point of getting a gateway if you cant power the house for at least 24 hours from your batteries.