Micro inverters Vs Optimisers in shaded instalation


I recently received this advice from a supplier I asked for a quote for my situation in a shaded area, regarding Optimisers Vs Micro inverters. reply is as follows:

Using an inverter technology like SolarEdge with optimisers behind every panel, or even using a string inverter like a Fronius with TIGO optimisers behind every panel, still have a weakness when compared to Micro inverters. Optimisers work well when some of the panels are shaded, but in order to continue functioning, they always need at least 6 panels to be receiving sunlight… If most of the array is shaded, and there are only 4 or 5 panels left receiving sunlight, these optimised systems will not function. With micro inverters on the other hand, you could have every single panel shaded except for just 1, and that 1 panel will still keep pumping out its full power completely unaffected by all the other shaded panels.

So, for moderate/partial shading, I would have recommended SolarEdge optimisers, but because you roof is subject to even heavier shading at times, Micro inverters are the better choice long term.

Supplier name with held.

Thanks in advance


Hi @harrisga

I believe what he is saying is accurate. I haven’t used optimisers before, but I understand that it is true regarding needing a number of panels to produce power for the inverter to function.

I guess the logic that if you have heavy shading then you should use micros is probably fair also. Although, if your shading is that bad, are you sure you’ll get enough sunlight for solar to be worthwhile? Is the supplier able to give you an idea of the output of the system, and what impact the shade will have?



I just reviewed your roof photos and quotes again. I agree with supplier, Enphase is a good option there I think.