How should I connect my panels/do I need optimizers?

elilanda

Hey everyone,

Im planing on installing solar system at my house. The thing is my roof isn't flat, and its facing multiple directions (main direction is 35 NE)

I made a 3D model of my roof and placed panels where there is place -

The thing is, some the panels will be shaded during the day (different panels depending on the time), so my question is - Do I need to get optimizers? If so, it needs to be on all the panels or only on the ones that get shaded?

I thought about "batching" to "stringing" couple panels with the same shading curvature is series and connect them in parallel to the Inverter and by doing so avoid the use of optimizers, is it ok? Is there any other solution (other than micro-inverters).

bullit_dodger

Hmm, interesting roof layout.

Couple of points to be aware of.

1. If you are going for the grant, you'll need 50cm gap to the edges of the roof. Couple of panels above there seem to be right at the limit. The SEAI folks won't sign off on the grant if you don't adhere to this rule. If your not going for the grant, then "have at it" - your dime, your roof.
2. Are you going for a battery? If you are not, then micro inverters might be a better option. They usually come in 1, 2 and 4 panel options, so you should be able to come up with a solution there for your roof.
3. With respect to #2, if you went micro-inverters, you'll struggle to get installers and or NC6 sign off, as opposed to a string inverter where you might have 8-9Kwp of panels on say a 5Kw inverter, your limit would generally be 5Kw of panels or so as that's what you have with NC6 nowadays.
4. With 28 panels and call it (say) 400w per panel, that's 11.2Kwp. You'll struggle to get that all installed and stay compliant.

elilanda

https://www.boards.ie/discussion/comment/122514781#Comment_122514781

Thanks for your answer! And yes that's a terrible roof layout for a solar system I know..

Im not going for a battery, and I looked up micro inverters and it seems more cheap to go with optimizers.

Didn't really understood points 3 and 4, what is NC6? and what do you mean by "get that all installed and stay compliant"? English is not my native language so it may be a language barrier.

SD_DRACULA

You can defeat the non compliant SEAI nonsense very easily, leave all cables from the panels which are "non compliant" unplugged from the inverter, the inspector will have to exclude them from the assessment.

That was told to me by the the inspector as I had some "non compliant" panels and they made me change them before giving the grant.

10-10-20

https://www.boards.ie/discussion/comment/122514862#Comment_122514862

Are you based in Ireland? If not then a lot of the info about SEAI is not relevant.

You're going to have some difficulties with those aspects and the shading. When you said that the main direction is NE, does that mean that 23 of the panels are facing NE, or how is the orientation working out for the roof as it's not clear.

I think I'd do two strings like this:

Green and red. If the panels are "half-cut" types (with dual bypass diodes) then you should not need optimisers on the panels at all.

I'd ditch the panels with the red X - they are just going to give you problems due to shading. As for the others, micro-inverters would be best for them as @bullit_dodger said.

idc

https://www.boards.ie/discussion/comment/122514862#Comment_122514862

If you are in Ireland (not sure of rules if your in Northern Ireland) and connecting to the grid you need to submit a NC6 form to inform ESBN that you'll be connecting an inverter to the grid.
see here for much more info

Micro-Generators (esbnetworks.ie)

slave1

are you out the country? ground mount an option?