Should I optimise this string

[u/cameronpc]

I am in a bit of an interesting position - the array you see here faces WSW - there is another one that faces opposite. This array has no shading from the chimneys you see but the other one does.

I historically have installed solaredge systems for family members and previous houses (as an enthusiast) - there are some shading issues at this property but mostly due to the parapit wall the end in the evening, I hear bypass diodes are meant to help but I cannot conclude they will help in this scenario and whether its worth fitting the optimisers before I fit bird mesh and take scaffolding down. I am concerned its taking the whole string out.

Today was a clear day but there has been several huge jumps in power (could just be the inverter).

I have a 6kW SolarEdge Inverter from my old house and 12 x S500B's I can put on before the scaffolding comes down. But wondering whether its worth doing economically (as my new hybird inverter was cheap) and whether the gain is worth it, I reckon somewhere between 9 and 13%?

Panels are JA Solar 525W bifacials x12

Current Inverter is a 6kW Solis Hybrid Inverter - would save me from installing a seperate AC coupled battery.

Any help would be great, thanks!

[u/rob_nosfe]

There is absolutely nothing an MLPE (module level power electronics i.e. optimizers or micro inverters) can do with this kind of shading that isn't already done by the modules themselves. MLPE don't work at cell level.

Let's get some context: your solar modules have a white bar in the middle with 3 diodes behind it. Every diode is connected to its upper and lower cell subset (two columns) in a parallel configuration, so when the bottom half is shaded current will only flow on the upper half. No MLPE nor diode involved. Diodes were historically implemented to deal with shadows entering or exiting the long side, not the short. In fact part of the reason half-cut technology got developed recently is being able to also deal with shadows hitting the short side of the panel.

Note that every cell subset has all its cells in series, so when the first (lower) cell gets shaded the whole subset gets a spike in internal resistance, forcing the current to flow somewhere else. If you had full cell modules it couldn't flow anywhere, you have half-cut modules so it flows on the upper half. We are obviously talking half the current, we can't squeeze sun out of shade.

[u/cameronpc → u/rob_nosfe]

thank you! this is very useful, so not even optimisation from the one at the far end (thats more shaded than the others) will help?

[u/rob_nosfe → u/cameronpc]

Sadly no, but for another reason: diagonal shading mitigation is no easy task. I remember a specific field test published by the European PV magazine "Photon International" in 2013 or so, that couldn't lead to any yield gain at all with MLPE and this specific type of shading.

[u/Riplinredfin]

Thats a bizarre roof the way it meets in the middle.

[u/MaximusMeridius26006 → u/Riplinredfin]

I think the term is azimuth of the roof.

[u/Riplinredfin → u/MaximusMeridius26006]

Alot of water would be collecting in the middle.

[u/Ok_Garage11]

Optimization is for differences between panels, it won't help when a panel is partly shaded unfortunately.

[u/cameronpc → u/Ok_Garage11]

there is a difference between the far panel and the rest though - its just whether its worth optimising for this.

[u/Ok_Garage11 → u/cameronpc]

If there was one with no shading, yes optimizing that one when the others are shaded would help, but in your pic they are all shaded.

[u/iSellCarShit]

I doubt you'd gain anything, shading is pretty uniform across this string

[u/cameronpc → u/iSellCarShit]

not even from optimisation from the one at the far end?

[u/iSellCarShit → u/cameronpc]

No, best thing to do is enable global tracking/ shadow scan on the inverter, if it's an option

[u/Pergaminopoo]

What would Prime do?

[u/ResidentOfMyBody]

Your best bet would be to have those modules be in landscape orientation rather than portrait, so that they aren't shaded across all cell groups.

[u/ObjectiveResistance]

You could rotate the panels 90 degrees. Right now when you have shade at the bottom, all 3 bypass diodes will be activated rather than 1/3rd or 2/3rd of them.

[u/pastein]

Reverse tilt your panels. That should help.

[u/DFX74]

Judging from the architecture, I’m guessing you’re in the UK or East Coast of the US. Solar Edge Optimizers should be installed and since you have a hybrid Energy Hub Inverter, your generation capacity should be adequate for charging. Regarding the shading issue:
Optimizers help with shading issues similar to Micro Inverters so should prevent entire string from disengaging with production. Rom e the overlapping panel, reduce the shadow footprint that’s my opinion

[u/cameronpc → u/DFX74]

in the UK, thanks!

[u/TransportationOk4787]

Check out this video before spending money on optimizers

https://youtu.be/Ur1HXsx09Jw?si=HjU_ublMJc4W5JkV