Difficult decision about solar panels setup

UnhappyCustomer

My idea was to get 19 x 420 panels (7.9 kW), but after having the roofers here and looking into the possibilities, the funny roof wouldn't allow that.

Now, the possibilities I have are:

1. Put panels in the shed. I could fit way more panels but I need to upgrade the cable from the house (or the grid) to the shed + a fuse board, cut a couple of trees, and it would still get some shade during the winter from a house nearby.
2. put panels in the south and west front roof 15 x 420 (6.3 kW) with 2 optimisers or trimming a massive tree (around €2/3k)
3. put panels in the south, west front and west back roof 18 x 420 (7.5 kW) but the west back roof would barely get sun during the winter as it would be covered by another roof.

What do you think would be the best financial-efficient option?

10-10-20

Option 2 I think sounds like it might be viable...? Does it only need a dual MTTP inverter or how were they planning on laying out the strings?

Why only 2 optimisers, are two more shaded than the rest and does the installer's choice of optimiser allow him to install just two optimisers rather than having to install one on each panel (some brands do and some don't)?

Does option 3 need three MTTP strings?

UnhappyCustomer

https://www.boards.ie/discussion/comment/120982421#Comment_120982421

2 strings, each string can take up to 10 panels.

2 optimisers because it would be the ones affected by the shade of a tree but it may need more.

Now what I wonder is how much does the direct sun really matters depending on the time and season?

I could get direct sun on the west back roof but it would be just at the end of the day during summer or none during winter.

this is south - west front at the end of April at 8pm

This is the west back and north at the end of April at 12pm

10-10-20

I see your predicament there.

I'm tempted to say South - West as the aspect is better and you appear to have more available roof-space, but as you say you're going to have shading losses for a good part of the year.

What do others think?

UnhappyCustomer

https://www.boards.ie/discussion/comment/120983203#Comment_120983203

@bullit_dodger would you have a saying here? I remember our conversation here https://www.boards.ie/discussion/2058294263/microinverter-or-hybrid-inverter

TerraSolis

Can we see the shed?

UnhappyCustomer

https://www.boards.ie/discussion/comment/120985946#Comment_120985946

the tree circled in red has been taken down

UnhappyCustomer

would anybody else have an input or suggestion here?

10-10-20

https://www.boards.ie/discussion/comment/120996687#Comment_120996687

Pop a post into the Solar for Dummies thread and see if you get more feedback there?

TerraSolis

https://www.boards.ie/discussion/comment/120986465#Comment_120986465

That's a lot of shade all right ... I wouldn't consider the shed a runner. What about simply plastering all roof aspects - takes the hesitation out of it haha