Tigo optimisers with half cell panels

[green_bean]

Good morning all.

I've been researching into when and where optimisers are required for arrays, and would be super helpful if I could tap into the huge knowledge base on here.

I've been advised that the newer half cell panels (mostly looking at JA & Qcell 365W panels) have blocking diodes that give them a rudimental version of a built-in optimiser, thus removing the need for individual optimisers (I'd be using the Tigo brand) unless a panel is fully shaded in an array.

Does anyone know if this is true?

I'm struggling as everyone I speak to seems to have an agenda RE selling me specific products.

My understanding is that if a half cell panel is half-shaded, then the other half can function as normal, and that it doesn't need to be optimised. It's only if say 1 panel out of 8 in a string is fully shaded, then it would need optimising...

All help/thoughts appreciated!

Cheers,
green_bean

[oregon_phil]

Good morning all.

I've been researching into when and where optimisers are required for arrays, and would be super helpful if I could tap into the huge knowledge base on here.

I've been advised that the newer half cell panels (mostly looking at JA & Qcell 365W panels) have blocking diodes that give them a rudimental version of a built-in optimiser, thus removing the need for individual optimisers (I'd be using the Tigo brand) unless a panel is fully shaded in an array.

Does anyone know if this is true?

I'm struggling as everyone I speak to seems to have an agenda RE selling me specific products.

My understanding is that if a half cell panel is half-shaded, then the other half can function as normal, and that it doesn't need to be optimised. It's only if say 1 panel out of 8 in a string is fully shaded, then it would need optimising...

All help/thoughts appreciated!

Cheers,
green_bean

There is plenty of info online that supports your understanding of half cut solar cell panels and potential shading benefits.

Factors that might influence your decision.

1) Is this a roof mount installation where you need to install a rapid shutdown device anyway?
2) Exactly how will shade hit the solar panel? Shape of shade and solar panel orientation will influence whether or not only 1/2 of solar panel will be affected by shade.
3) You won't know the exact benefit of adding optimizers vs no optimizers even if you perform the experiment on the exact same array. Solar panels at time zero have no aging effects and are very very clean. As time goes on, everyday dirt, dust, leaves, bird droppings, solar panel aging, etc. will reduce maximum power output potential.

The cost difference between a rapid shutdown device and a Tigo TS4-A-O is about $20. For the optimizer solution, you also need a Tigo CCA and TAP which might run another $200. From what I understand, Tigo optimizers are buck only devices that are robust (no capacitors). My installer hasn't seen any Tigo Optimizer failures.

I have some winter shading so I opted to have Tigo optimizers installed on all my panels. For me it was worth it to install optimizers on all my panels because my panels are on a 16' roof and I only want to pay labor costs to do this once.

[Mike90250]

any solar panel with diodes, has bypass diodes, not blocking diodes.
The blocking diode function is contained in most charge controllers built after the 90's

link to an explanation with cheesy ads

https://solartechadvisor.com/bypass-blocking-diodes/

[green_bean]

any solar panel with diodes, has bypass diodes, not blocking diodes.
The blocking diode function is contained in most charge controllers built after the 90's

link to an explanation with cheesy ads
https://solartechadvisor.com/bypass-blocking-diodes/

This is really interesting, thanks!

Correct me if I've misunderstood this, but it does seem to confirm my thoughts that the bypass diodes negate the need to use optimisers to a certain degree..

In my scenario where I have 8 panels (for reference, model #JAM60S-21-365-MR-AB-MC4-SM) as mentioned above they are JA or Qcell half cell) roof-mounted, and 2 panels experience shading over half the panels but are still producing a good current, they do not need to be optimised?

[Mike90250]

By-Pass diodes should exist in all PV panels and perform a simple function of keeping some panel output alive

Optimisers, actively manage the available power of un-shaded cell groups of a panel, and trade voltage for amps, so that one panel being shaded, won't throttle the whole array back.

Optimisers CANNOT produce power that does not exist. An entire shaded panel produces pretty much nothing, so there is nothing for an optimizer to work with. Bypass diodes then have to pass the power of the entire array, and eventually burn out, because they seldom have proper heat sinking. Optimisers will not prevent bypass diode burnout.