I didn't bother with micro and went with string. There is no shading on the roof and the price of micro Vs the percentage gain didn't make it worth it for us. Payback period was far too long

Not sure if this is specific to the string inverter used or more general to modern equipment but I found this interesting from NRG Solar in Australia

@ken 

Great video thanks for posting, just my kind of testing I.e real life

Decision made

We have two string running to a Ginlong Model 8D inverter (which is quite old now) here you can see some shading and it's impact on generation... Exactly why I got the EmonPi to see what impact the winter shading was having on the generation. Don't know what a new inverter would do for us.

Someone tried to sell us a Solar Edge inverter without even looking at what we had... I was wanting to talk to them about a new ground mount system but never got a chance to even ask about that so sales lost out there...

@ken I've been looking into a string inverter for two new roof arrays with some slight intermittent shading.  I also found this video to be really informative, and encouraging.  I would like to avoid optimisers etc up on the roof if at all possible.

The video demo used a Fronius Primo inverter, which uses something called Dynamic Peak Manager.  Looking it up it seems to be their version of Global MPPT.  

I've been trying to establish how commonplace Global MPPT is in today's solar inverters, as it seems to be a notable benefit when operating a shaded string.  For example, I contacted Givenergy about their inverters but the tech support team didn't have any information beyond their datasheet.

Any opinions at all would be greatly appreciated. 🙂 

That was a gret little demonstration is that vid.

I did a bit more searching to try and find out why that is and this vid came up and to me helped explain very clearly in pretty straight forward terms what is going on with shading

Assuming this is accurate, it seems the simplest summary (anyone feel free to correct me if I'm wrong!) is that optimisers and microinverters are great for maximising output when the shading is diffused and there is essentially still some light reaching all of the cells on the panel (distant tree or cloudy inclement weather) or there's a small shadow (e.g. cable across a panel), but when the shading is heavy and blocking out a cell or more, there's no real difference as was demonstrated in the NRG video.

I agree with your summary, which was very surprising to me as I was always under the impression that the heavier the shading the greater the case for microinverters/optimisers!

Posted by: @skd

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@ken I've been looking into a string inverter for two new roof arrays with some slight intermittent shading.  I also found this video to be really informative, and encouraging.  I would like to avoid optimisers etc up on the roof if at all possible.

The video demo used a Fronius Primo inverter, which uses something called Dynamic Peak Manager.  Looking it up it seems to be their version of Global MPPT.  

I've been trying to establish how commonplace Global MPPT is in today's solar inverters, as it seems to be a notable benefit when operating a shaded string.  For example, I contacted Givenergy about their inverters but the tech support team didn't have any information beyond their datasheet.

Any opinions at all would be greatly appreciated. 🙂 

 

@skd did you find any information on Global MPPT?  I'm particularly interested in whether GivEnergy's inverters have it (not had a sensible answer from the Facebook GivEnergy forum ;-(